HomeMy WebLinkAbout5-18-2015 Complete WRAB Packet
WATER RESOURCES ADVISORY BOARD MEETING
MEETING DATE: Monday, 18 May 2015
MEETING TIME: 7:00 p.m.
MEETING LOCATION: Municipal Services Center, 5050 Pearl St., Boulder, CO 80301
Agenda Highlights:
1.Call to Order (7:00 p.m.)
2.Approval of 27 April Meeting Minutes (7:01 p.m.)
3.*Public comment (7:05 p.m.)
4.*Public Hearing and Consideration of a Recommendation to City Council Regarding the Skunk
5.*Public hearing and Consideration of a Recommendation to City Council Regarding the South
Boulder Creek Floodplain Mitigation Plan (7:45 p.m.)
6.Information Item Preliminary Capital Improvements Program (9:15 p.m.)
7.Matters (9:45 p.m.)
From Board
From Staff
8.Discussion of Future Schedule (9:55 p.m.)
9.Adjournment (10:00 p.m.)
Additional Information Items:
Boulder Civic Area Update
Boulder Creek Mitigation Plan
GAC (Greenways) CIP
* Public Comment Item
Agenda item times are approximate.
Information:
Please contact the WRAB Secretary email group at:
WRABSecretary@bouldercolorado.gov
Packets are available on-line at: http://www.bouldercolorado.govA to ZWater
,
Resources Advisory Board (WRAB), Next Water Resources Advisory Board Meeting
CITY OF BOULDER, COLORADO
BOARDS AND COMMISSIONS MEETING MINUTES
Name of Board / Commission:
Water Resources Advisory Board
Date of Meeting:
27 April 2015
Contact Information of Person Preparing Minutes:
Andrea Flanagan 303.413.7372
Board Members Present:
Vicki Scharnhorst, Dan Johnson, Ed Clancy, Mark Squillace
Board Members Absent:
Lesley Smith
Staff Present: Jeff Arthur, Director of Public Works for Utilities
Annie Noble, Flood and Greenways Engineering Program Coordinator
Katie Knapp, Engineering Project Manager
Kristin Dean, Utilities Planner
Ken Baird, Utilities Financial Manager
Douglas Sullivan, Acting Principal Engineer for Water, Wastewater and Stormwater
Tom Settle, Water Treatment Manager
Ward Bauscher, Engineering Project Manager
Kevin Clark, Utilities Project Manager, Sourcewater Infrastructure
Steve Buckbee, Engineering Project Manager
Christin Shepherd, Civil Engineer
Milford John-Williams, Budget Analyst
Andrea Flanagan, Board Secretary
Cooperating Agencies Present:
Alan Turner, Senior Project Manager, CH2M HILL
Shea Thomas, Urban Drainage and Flood Control District
Meeting Type: Regular
Agenda Item 1 Call to Order [7:00 p.m.]
Agenda Item 2 Approval of the 16 March 2015 Meeting Minutes [7:00 p.m.]
Motion to approve minutes from March 16 as presented.
Moved by: Seconded by:
Squillace; Johnson
Vote: 4:0 (Lesley Smithabsent)
Agenda Item 3 Swearing In/ Election of Officers [7:03 p.m.]
Ed Clancy was sworn in for his term on the WRAB.
Motion by: Clancy; Seconded by: Squillace
Move to postpone election of officers until such a time as all five board members are present to vote.
Current arrangement of officers would continue until that time.
Vote: 4:0 (Lesley Smithabsent)
Agenda Item 4 Public Participation and Comment [7:04 p.m.]
Public Comment:
Karl Anuta, Crif Crawford, Bruce Thompson (each speaker took a portion of the pooled time)
Karl Anuta spoke on behalf of residents of Frasier Meadows Retirement Community and presented a
petition with signatures to the Board to ask for their support in the construction of a flood control facility,
south of highway US 36. Citizens are concerned about the South Boulder Creek area, which the city has
studied for many years. Over 300 homes of the total homes damaged by the flood event were on the west
side of Foothills. This is not a flood that came up through basements, or caused by an over-taxed sewer
system. This flood damage was caused strictly by surface water flowing over the turnpike and into homes,
including several major buildings. Asking for Board support for construction of this area.
Crif Crawford:
Showed videos of flooding at: Table Mesa and US 36, Frasier Meadows (from Thunderbird), Underground
Garage to illustrate the flows and seriousness of the flood waters in their community.
Bruce Thompson
Asking for Board support to further prevent water from South Boulder Creek Basin from topping over US
WRAB Minutes
27 April 2015
Page No. 1
36 andoverflowinginto residential areas, west of Foothills Parkway. Highest priority is saving lives. If
anyone had been in the Frasier Meadows parking garage, they might not have survived. It took less than 15
minutes to take 88 cars. Residents had to be carried across 3 feet of water to safety, which is a miracle that
no one was lost. 43 residents of Frasier Meadows are present today and instead of speaking individually,
they signed a sheet agreeing to these comments.
Al LeBlang
Concurs with the aforementioned statements.
Clinton Heiple
This was not a gently rising flood; this was water that came on very quickly and if anyone had been
sleeping in their basement they could have died. Primary responsibility of government is to protect the
lives and safety of its citizens. Hopes for Board to move forward.
Laura Tyler
Member of the South Boulder Creek Steering Committee, shared update about what the group is doing.
Concerned that safety piece was not addressed at earlier study session. Group has reached out to City
Council members, as well as University of Colorado (CU) staff. Reactions have been overwhelmingly
positive. Council sees this as an opportunity to cooperate with CU. CU representatives are very positive
and both groups clearly see the seriousness of this situation. There is a feeling of momentum. Shared a
clip from Daily Camera about annexation and shared quote about for South Boulder Creek
Mitigation Project and Southeast Boulder section and wanted to include this as part of the conversation.
This conversation is happening and it is very positive.
Payson Sheets
Spoke about a possible future hazard that he would like to have avoided, with regard to expansion of Eldora
cooperatively with
residents, but they are now unwilling to listen to residents. Sediment load is going into Peterson Lake and
they would like to build additional trails, which would cause greater sediment issues. The ski area has been
granted an expansion in both directions. EPA in Denver looked at their plans and found that the
environmental impact statement was incomplete, and they were unable to assess the environmental impacts.
Feels that this needs to be reassessed by the City. Nederland Advisory Board is preparing objections and
he urges Board to file a firm objection to the expansion. Read from a key statement by Bret Linenfelser
from April, 2014. Appreciates anything the Board can do to protect Boulder Creek.
Jim Johnson
Represents Southeast Boulder Neighborhood Association, which includes surrounding neighborhoods.
, which is that they want to work together with the City,
County and FEMA to prevent water from further flooding these neighborhoods. Held up a map to show the
Board. Hopes group can plan ahead with University of Colorado and would appreciate anything the Board
can do to work with these entities to help protect residents. Mitigation is needed badly.
Agenda Item 5 [7:28 p.m.]
Public Hearing and Consideration of a Recommendation to City Council Regarding the Gregory
Creek Mitigation Study
Katie Knapp and Utilities staff presented the item to the board.
Executive Summary from the Packet Materials:
The purpose of this memorandum is to present the Gregory Canyon Creek Draft Flood Mitigation Plan
(Attachment A)
The city has retained CH2MHill to evaluate potential alternatives to help alleviate future flooding along
s included as
(Attachment A).
Appendix A of the Draft Flood Mitigation Plan This Analysis contains a detailed
description of the data and models used to determine the improvements which would help flood
conveyance along Gregory Canyon Creek. The intent of the Analysis was to identify various types of
improvements which could be constructed along the creek corridor, assess the costs and benefits associated
WRAB Minutes
27 April 2015
Page No. 2
Staff reviewed the Analysis and developed a staff recommended plan based on the engineering
recommendation, input from the public and observations from the 2013 flood event. The staff
(Attachment
recommended plan is illustrated graphically in Section 6 of the Draft Flood Mitigation Plan
A)
which also includes additional information about the Gregory Canyon Creek watershed, the planning
process and the alternatives considered. Please note that not all sections of the document have been
completed. Pending consideration and input from WRAB, conceptual drawings will be developed and the
mitigation plan will be finalized and presented to City Council for acceptance.
WRAB Discussion Included:
Question about four private culverts and asked if property owners agree to dedicate easements in
order for city to install
Question if residents support installing a pedestrian bridge.
Stated that it is likely that we will exceed a ten-year flood and questioned if infrastructure will
support anything greater than a 10-year flood.
Asked about the cost-to-benefit analysis and questioned the numbers presented because they did
not match what is in the report.
Commented that a 7% discount rate is not realistic. Concerned that if the discount rate is changed,
the numbers will be skewed.
Suggests the calculations be made under different discount rates. Numbers seem speculative.
Stated that the culvert replacement over the ten-year event does make sense.
Asked for further clarification on method used for property acquisition.
Stated that it is odd that city would agree to pay for the easements and suggested further
discussion of this topic.
Asked if there is a consideration at this time for what would come first as a priority, so that larger
problems are not created and requested further clarification of the overall timeline approach.
Questioned how the benefits get assessed in this situation.
Requested further clarification on road improvements and property acquisition and whether these
aspects could not be made part of the recommendation and instead, be a part of another program?
Stated that this project affects neighborhoods directly and recommends a more adaptive approach
that allows adjustments as more information is found out and suggests adding this to
recommendation.
Requested clarification on whether there is a reason that street improvements need to be included
in the recommendation.
Stated that Board has been discussing Gregory Creek since 2008 and something needs to happen.
Requested whether it is normal practice for landscaping to be replaced, if damaged.
Recommended that residents be asked to grant easements without compensation, as to allow
funding to be stretched.
Stated that if property value increases, it seems odd that the city would pay for easements.
Public Comment:
Holly Pearen
Stated that staff and Board have been very open and solicitous to the neighborhood concerns. As the plan
has developed, the landowners have some concerns, both on macro and micro scales. Inconsistencies lead
to deep concern. Glad that benefit-cost analysis has been addressed. The value of the damages presented
in the documents are inconsistent. Has to be some sort of calibration to what actually happened.
Understands that the damages are estimated, but this cannot be accurate. No realistic assumptions about
the value can be made based on these numbers. Open to hearing explanation as to how these numbers were
arrived at from CH2M Hill. Landowners would appreciate if city and CH2M Hill could be more
transparent about the cost to landowners. If in fact properties gain or lose value, tell them how much and
reflect this in the budget. If easements will be given to the city for free, this may not be realistic, especially
based on her experience throughout this process.
Stewart Machle
Would like to thank city for all the help given to him since the flood. Rock walls have been rebuilt.
WRAB Minutes
27 April 2015
Page No. 3
Question about intersection of Anderson Ditch and Gregory Creek. Heard comment about an overhead
culvert or culvert separate from Gregory Creek and agrees they should be separated. Asks if a decision has
been made about what is going to be done with this location, as this is a critical area.
Laz Nemeth
Asked why everyone is in favor with box culverts. They are ugly. Preference is for keeping Anderson
Ditch open so children can play there. Running water is aesthetically pleasing. Based on personal
experience, Anderson Ditch was actually shut off during the flood. There was no more flow in Gregory
Creek afterwards. Something needs to be done. Asks if there is a reason for always having two box
culverts and if it is more cost-effective.
Rebecca Roser
Part of her property is Anderson Ditch, which goes to the edge of her property. Flows stopped in Anderson
Ditch, because it was filled to the top with silt during the flood. Agrees that the area where Gregory Creek
t the edge of her property. Appreciates that
neighbors have been solicited and looking forward to working with city with regard to easements.
Motion by: ; Seconded:
Squillace Johnson
Vote: 4:0 (Lesley Smithabsent)
Motion Passes
Staff requests Water Resources Advisory Board consideration of this matter and action in the form of the
following motion:
Motion to recommend the Gregory Canyon Creek Flood Mitigation Plan be finalized based on the
Staff Recommended Plan and presented to City Council for acceptance.
Agenda Item 6 [8:40 p.m.]
Information Item Preliminary Draft 2016 Utilities Budget (Water, Wastewater and Stormwater/
Flood Management) including the 6-year Capital Improvement Program (CIP)
Douglas Sullivan, Ken Baird, Annie Noble, Kevin Clark, Steve Buckbee, and other Utilities staff
presented the information item to the board.
rocess, Utilities develops a six-year planning budget, this year for the
time period of 2016 through 2021. The Water Resources Advisory Board (WRAB) role in this process is
s and capital
and expenditure projections for each of the three utility funds through the year 2021. Within the budget
process, City Council approves and appropriates funds only for the first year, 2016. In addition to the six
year CIP described above, Utilities staff develops a 20-yr CIP. The purpose of the 20-yr CIP is to look at
long range needs for all three utilities. The 20-yr CIP is a valuable mechanism to look at upcoming
regulatory requirements, asset management needs for aging facilities, and the associated debt service for
existing bonds.
IP. Input
from WRAB will guide staff in preparation of a draft CIP for discussion by WRAB at the May meeting.
WRAB will be asked to make a recommendation to City Council regarding the 2016-2021 CIP at its June
meeting. The Planning Board will review the complete city CIP, including utilities, in July. City Council
generally plans for two study sessions in September, prior to adopting the 2016 budget.
WRAB Discussion Included:
Stated that there is some concern that the rate increases may be a bit heavy, considering they have
been flat for so long. Concerned This could largely impact
commercial users.
Stated that perhaps we should exercise more thoughtfulness on how we conserve water and
consider the possibility of selling our product (water) while we have it. If we continue to
conserve, what are we losing in revenue?
WRAB Minutes
27 April 2015
Page No. 4
eed to acquire new
water supplies.
Stated that these changes could be more significant than the public may even understand.
Expressed concern that we may be on a track that is not aligned with inflation.
Stated that what some local communities want that is in the best interest of protecting their
properties, may not actually be w
Commented that we do need to play catch-up on sewage updates, as we saw what happened during
the flood event in 2013.
Stated that CII was never completed and suggest revisiting.
Asked whether there is any potential to sell any of our resources to generate additional revenue.
Questioned whether our plant investment fee is high enough and whether or not it is fair for people
who buy in later.
Questioned if there was any conclusion that came from the inspection of sewer lines that were
inspected by a pipeline
Agenda Item 7 Matters from the Board: [10:12 p.m.]
Board Member Clancy brought up the below matter(s):
Requested clarification on dates for future open houses.
Requested to find out if PowerPoint presentations will be posted following meetings.
Board Member Johnson brought up the below matter(s):
Requested more information on Eldora expansion, with regard to public comment.
Agenda Item 8 Matters from Staff: [10:15p.m.]
Kim Hutton provided an update on water supply for 2015. There is no need to implement water
restrictions at this time, based on current snow pack conditions.
Department of Health and Human Services has recently released a fluoride recommendation.
City is determining next steps and will follow up at future meeting.
Agenda Item 9 Future Schedule [10:24p.m.]
May:
South Boulder Creek Mitigation
Skunk Creek Mapping Update
Update on Wastewater and Stormwater Collection System Master Plans
Preliminary Capital Improvements Program update
Boulder Civic Area Update
Boulder Creek Mitigation Plan Update
Adjournment [10:31 p.m.]
There being no further business to come before the Board at this time, by motion regularly adopted, the
10:31
meeting was adjourned at p.m.
Motion to adjourn by: ; Seconded by:
JohnsonSquillace
Motion Passes 4:0 (Lesley Smith absent)
Date, Time, and Location of Next Meeting:
Monday, 18 May 20157:00 p.m.,City's Municipal Services
The next WRAB meeting will be at at the
Center, 5050 Pearl St., Boulder, CO 80301
APPROVED BY: ATTESTED BY:
_______________________________ __________________________________
Board Chair Board Secretary
_____________________________ ___________________________________
Date Date
An audio recording of the full meeting for which these minutes are a summary, is available on the Water
Resources Advisory Board web page.
https://bouldercolorado.gov/boards-commissions/water-resources-advisory-board-next-meeting-agenda-and-packet
WRAB Minutes
27 April 2015
Page No. 5
C I T Y OF B O U L D E R
WATER RESOURCES ADVISORY BOARD
AGENDA ITEM
MEETING DATE: May 18, 2015
AGENDA TITLE:
Public hearing and consideration of a recommendation to City
Council regarding the Skunk Creek, Bluebell Canyon Floodplain
Mapping Update
PRESENTER/S:
Jeff Arthur, Director of Public Works for Utilities
Annie Noble, Acting Principal Engineer for Flood and Greenways
Katie Knapp, Engineering Project Manager
EXECUTIVE SUMMARY
Floodplain mapping provides the basis for flood management by identifying the areas at
the highest risk of flooding. This information is essential for determining areas where
life safety is threatened and property damage is likely and is the basis for floodplain
regulations and the National Flood Insurance Program (NFIP).
maps need to be periodically updated to reflect changes in the floodplain resulting from
land development, flood mitigation improvements, new topographic mapping information
and new mapping study technologies.
The Skunk Creek Floodplain Mapping Update includes the , Skunk and
Bluebell Canyon Creek floodplains between the city limits to east of Foothills Parkway
where Skunk Creek confluences into Bear Canyon Creek as shown in red below.
AGENDA ITEM #4 PAGE 1
Engineering consultants provided hydraulic modeling to update the existing Federal
Emergency Management Agency (FEMA) Flood Insurance Rate Map (FIRM) and City
of Boulder floodplains, water surface elevations, conveyance and high hazard zones.
The proposed mapping of the Skunk Creek Floodplain would result in a net:
Increase of 38 structures identified in the 100-year floodplain;
Decrease of 22 structures identified in the conveyance zone and;
Decrease of 19 structures identified in the high hazard zone.
STAFF RECOMMENDATION:
Staff requests Water Resources Advisory Board consideration of this matter and action in
the form of the following motion:
Motion to recommend that City Council adopt the Skunk Creek, Bluebell Canyon
floodplain mapping update.
COUNCIL FILTER IMPACTS:
Economic:
Flood insurance is required for properties located in the 100-year
floodplain if they are financed by a federally-backed mortgage. Flood insurance
rates are set by FEMA based on the flood risk as shown on the flood insurance
rate maps. Accurate floodplain mapping helps facilitate accurate flood insurance
rates. The average annual rate for flood insurance within the city in 2014 was
$760 (3,830 policies)
the 100-year floodplain. Flood protection land use regulations also create costs for
property owners in the form of permit fees, increased costs of remodeling, and
restrictions on development. Flood insurance and land use regulations do,
however, provide protection from potentially catastrophic losses due to floods.
Environmental:
Flood events can result in damage or destruction to buildings
and corresponding release of man-made contaminants. Flood waters can also
cause erosion and damage to areas of the natural environment that are not capable
of conveying high-velocity stormwater. Updated flood mapping more accurately
identifies the areas with the greatest flooding risks and potential mitigation
opportunities.
Social:
Floodplain mapping provides the basis for flood management by
identifying the areas subject to flooding. This information is essential for
determining areas where life safety is threatened and property damage is likely.
Land use regulations help reduce risks to people and property in these high flood-
risk areas. Accurate mapping of flood risks also helps implement effective flood
preparedness and response programs, thereby increasing the safety of people
living, working or visiting the City of Boulder.
OTHER IMPACTS:
Fiscal:
Funding for this study is included in the Department of Public Works
Utilities Division budget.
AGENDA ITEM #4 PAGE 2
Staff Time:
Time for completing the study is included in existing work plans.
BOARD AND COMMISSION FEEDBACK
The Skunk Creek, Bluebell floodplain mapping was
first presented to the WRAB as an information item on August 18, 2014. The board
requested that staff continue to work with the public to inform them about the proposed
floodplain mapping and address comments and concerns. It was also requested that
(LOMA) process be made
available
the public and will continue to send out notification letters and postcards. Information
The floodplain mapping was then presented to the WRAB on September 15, 2014. At
the time of the WRAB meeting, additional refinements were being done to the mapping.
The WRAB passed the following motion with a vote of 3-2 (Clancy, Squillace opposed):
Motion to recommend that City Council adopt the Skunk Creek floodplain
mapping update including potential additional refinements made prior to
refinements result in substantial modifications to affected properties, that WRAB
would have the opportunity t
The opposition expressed a concern that an additional peer review should be conducted
for the work completed by Icon Engineering.
Icon Engineering had completed an initial peer review for the project in 2013 when the
mapping study was being done by Belt Collins. To address the boards concerns, a second
peer review was completed in January, 2015 by a third party consultant, Anderson
Attachment A
Consulting Engineers, Inc. The peer review comments are included as .
In response to the peer review comments, additional clarifications and minor revisions
Attachment B
were made to the study as described in .
After WRAB considers the mapping update, it will be provided to the Planning Board as
an informational item and presented to City Council for their consideration.
PUBLIC FEEDBACK
Public notification post cards about the mapping update have been sent to all property
owners in the study area and a project web site has been developed to provide
information (https://bouldercolorado.gov/water/skunk-creek-floodplain-mapping-update).
An open house was held on August 18, 2014 immediately prior to the WRAB meeting to
inform the public about the mapping update and hear comments and concerns about the
study. Staff has also met with residents in person and responded to phone calls and
emails. In general, most of the comments and questions have been about impacts to
specific properties and requests for more detailed information such as proposed base
AGENDA ITEM #4 PAGE 3
flood water elevations. There were also concerns about the high hazard zone delineations
th
and the distribution of the Bluebell Canyon Creek split flow paths downstream of 15 St.
In response to the public feedback, the high hazard zone delineations have been re-
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evaluated and refined. The flow distribution at 15 Street has also been reviewed. A
Attachment C
summary of the public feedback is provided in .
BACKGROUND
The risk of flash flooding is an important issue for the City of Boulder primarily due to
its location at the mouth of Boulder Canyon and other canyon creeks. Approximately 13
percent of the city is located within the 100-year floodplains of Boulder Creek and its 14
tributaries.
Floodplain Management
floodplain regulations and flood insurance can be found at:
Overview.
The city delineates four flood zones as described below:
500-year floodplain: The 500-year floodplain delineates the flood limits resulting
from a storm that has a 0.2 percent chance of occurring in any given year.
100-year floodplain: The 100-year floodplain delineates the flood limits resulting
from a storm that has a one percent chance of occurring in any given year (26
percent chance over a 30-year mortgage).
Conveyance zone: The conveyance zone is defined as the areas in the floodplain
that are reserved for the main passage of the entire 100-year flood flow when the
100-year floodplain is artificially narrowed until a maximum six-inch increase in
flood water depth is created. This zone is delineated to allow development to
occur up to the narrowed floodplain and still provide passage of 100-year storm
flows.
High hazard zone: The high hazard zone defines the area of the floodplain where
water depth and velocity pose a threat to life and safety. This area is delineated for
areas in the floodplain where water depths are four feet or greater or where the
water velocity multiplied by water depth equals or exceeds the number four.
Skunk Creek, Bluebell Canyon Creek, and Kings Gulch were first studied in 1987 by the
consulting firm Greenhorne & O'Mara and the resulting Flood Hazard Area Delineation
(FHAD) report included the delineation of the 100-year floodplain along these creeks.
The Flood Insurance Study (FIS) and Flood Insurance Rate Map (FIRM) approved for
these creeks were originally based on the 1987 FHAD and included a federally-regulated
one-foot rise floodway. Since that time, both the City of Boulder and the State of
Colorado have adopted a ½ foot rise floodway, which the City refers to as the
Conveyance Zone.
In 1989, Love and Associates delineated the High Hazard Zone and City of Boulder
Conveyance Zone (½ foot rise floodway). The delineations were based on the hydraulic
models used in the 1987 FHAD.
AGENDA ITEM #4 PAGE 4
On May 6, 1991, FEMA issued a Letter of Map Revision (LOMR) for Skunk Creek to
incorporate the results of a channel improvement project. The limit of the LOMR was in
of Colorado Avenue to just
upstream of the confluence of Boulder Creek.
Several road-crossing structures for Skunk Creek have been improved since the
regulatory floodplain was adopted in 1991. Culverts at Broadway and at 27th Way,
crossings at Anderson Ditch and the cemetery maintenance road, and the low water
crossing upstream of 27th Way were not included in the 1991 regulatory model, but were
incorporated into the current mapping study.
The City initially contracted with Belt Collins to develop the updated floodplain maps but
they closed their Boulder office in 2013. ICON Engineering provided a peer review of
1 initial study and was selected to complete the project.
In 2013, the city acquired state-of-the-art Light Detection and Ranging (LiDAR)
technology to produce high-resolution topographic mapping. The new LiDAR mapping
was compared to the 2003 topographic base mapping and areas showing substantial
differences were updated in the hydraulic models.
In December, 2014, Anderson Consulting Engineers was selected to complete a peer
review of the floodplain mapping study completed by ICON Engineering. The peer
Attachment A
review comments are included as . In response to the peer review
comments, additional clarifications and minor revisions were made to the study as
Attachment B
described in .
ANALYSIS
This mapping study updates the hydraulic models and flood hazard mapping for the 100-
year floodplain, Conveyance and High Hazard Zones for the entire reach of Skunk Creek,
including the and Bluebell Canyon Creek tributaries.
A 2-dimensional hydraulic model was developed for the creek system to determine
primary flow paths and split flow areas. Information from the 2-dimensional model was
-dimensional hydraulic model used for
the analysis.
The existing 100-year floodplain
Creek is primarily along the creek corridors and roadway areas with some spillage into
surrounding properties. The proposed 100-year floodplain is more extensive than the
existing mapping in most areas and bears resemblance to the September 2013 flood
extents. The September 2013 flood extents were not used to delineate the floodplains but
were used to check assumptions on flow paths. For Skunk Creek
Bluebell Canyon Creek, the September 2013 flood extents are similar to the proposed
floodplain mapping.
AGENDA ITEM #4 PAGE 5
The existing Conveyance and High Hazard Zone mapping for Bluebell Canyon Creek
did not include a significant neighborhood area that has a history of
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flooding east of 15 Street. The proposed mapping extends the Conveyance and High
Hazard Zones through this residential area to their confluence with Skunk Creek along
Broadway. The proposed mapping also extends the Conveyance and High Hazard Zones
for Skunk Creek north of Broadway to include more roadways, split flows and other
areas not previously mapped.
The revised mapping indicates a greater flood risk area in the Skunk Creek Drainage
Basin than was shown in the previous mapping. A majority of the structures newly
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identified as being at risk are located within the bounds of 15 Street to the east,
Broadway to the west, Baseline to the north and King Avenue to the south.
The High Hazard Zone (HHZ) was initially delineated based solely on the 1-dimensional
model results, which was the standard approach used in previous studies. Similar to the
new approach taken for the Upper Goose Creek and Two-Mile Canyon Creek floodplain
mapping study, the HHZ areas were re-evaluated by reviewing the 2-dimensional model
results. The proposed mapping was revised to delineate HHZ only in areas where results
from both the 2-dimensional and 1-dimensional models indicate HHZ areas. As a result,
several of the HHZ areas were modified and some isolated pockets were eliminated.
Attachment D
includes figures showing a comparison between existing and proposed
floodplain mapping and how the mapping impacts existing structures.
NEXT STEPS:
Following a recommendation of approval from the WRAB, the floodplain mapping study
will be provided to the Planning Board as an informational item so that it can be
considered for planning purposes. The study will also be considered by City Council for
adoption. If City Council approves the study, the city will submit a request to FEMA for
review. During the 2-4 year FEMA review and approval process, it is recommended that
the new mapping be used for regulatory purposes by regulating to the more restrictive of
the existing and proposed mapping. This would mean that development within the newly
identified flood zones would be subject to the city floodplain regulations. In accordance
with FEMA requirements, development within areas being removed from the floodplain
are e new
floodplain mapping. Following formal adoption by FEMA, the city would regulate solely
based on the new mapping.
ATTACHMENTS
A.Peer Review Memo dated Feb. 5, 2015
B.Response to Peer Review Apr. 27, 2015
C.Public Comments
D.Existing and Proposed Floodplain Maps
AGENDA ITEM #4 PAGE 6
Attachment A - Peer Review Memo dated Feb. 5, 2015
Attachment A - Peer Review Memo dated Feb. 5, 2015
Attachment A - Peer Review Memo dated Feb. 5, 2015
Attachment A - Peer Review Memo dated Feb. 5, 2015
Attachment A - Peer Review Memo dated Feb. 5, 2015
Attachment A - Peer Review Memo dated Feb. 5, 2015
Attachment A - Peer Review Memo dated Feb. 5, 2015
Attachment A - Peer Review Memo dated Feb. 5, 2015
Attachment B - Response to Peer Review Apr. 27, 2015
8100 S. Akron Street, Suite 300, Centennial, CO 80112 - Phone (303) 221-0802 / Fax (303)-221-4019
April 27, 2015
Ms. Katie Knapp, P.E.
Planning
Engineering Project Manager
Department of Public Works / Utilities Division
nd
1739 Broadway, 2 Floor
Boulder, Colorado 80302
Design
RE: Skunk Creek, Bluebell Canyon Creek, and King’s Gulch Request for Physical Map
Revision
Dear Ms. Knapp,
This letter provides responses to the comments provided by Anderson Consulting Engineers as
part of their peer review regarding the Skunk Creek, Bluebell Canyon Creek, and King’s Gulch
Request for Physical Map Revision – Hydraulic Report, dated August 1, 2014. A revised Hydraulic
report will be provided under separate cover.
Report Text
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1. On Page 6, Table 1, please change the location of Flow Change ID from 20 Street
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Street. Also, the 500-year discharge value appears to be incorrect at the
to 16
upstream study limit (the table indicates a discharge of 50 cfs, which is lower than
the 100-year discharge at this location). Please add a flow change location at
Cross Section No. 4282 in order to account for the inflow from Node B_2 from the
FLO-2D analysis as well as providing some explanation as to how this value was
determined.
Table 1 has been updated. The 500-year discharge has been revised. A flow change
occurs at cross section 4258 in order to account for the inflow from Node B_2. Please
note that the flow distribution between the Bluebell Canyon Creek and Mariposa Avenue
has been determined by the 2D model. The B_2 inflow value was determined by its
relative contributing size within the full drainage basin (flows to design point 212 in the
effective information).
2. On Page 8, the FHAD Design Point on the Skunk Creek outfall should be labeled
“306” instead of “302”.
The label has been revised.
3. On Page 9, Table 2, please change the River Station ID at Flow Change ID No. 1
from 4034 to 3841.
The table has been revised.
Skunk Creek, Bluebell Canyon Creek, and King’s Gulch Request for Physical Map Revision
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4. It is unclear as to why the 100-year discharge on King’s Gulch is 14 cfs lower at the
upstream study limit than at Bellevue Drive. It seems unlikely that discharge
would change over this short distance. Consider maintaining the higher discharge
at the upstream study limit for all return periods.
This was done to reflect reduced contributing area at the upstream limit of the study.
Discharges have not been revised.
5. Please explain why the peak discharges are lower (approximately 8-9%) in the last
line of Table 2 on page 9 than what is listed in the FHAD. For example, the 100-
year discharge in King’s Gulch is stated as 340 cfs in the table; the FHAD lists the
100-year discharge equal to 373 cfs.
This was done as part of the original project approach in order to address slight changes
in contributing area between this study and the FHAD.
6. The first paragraph on page 10 describing a hydrologic adjustment factor and the
distribution of flows into the Skunk Creek model from Bluebell Canyon Creek and
King’s Gulch is confusing. We would recommend reviewing the effective HEC-1
model in order to ascertain the timing of the flows at confluences. For example, it
appears as if the peak 100-year discharge between FHAD DP 301 and FHAD DP 302
should be between 640 and 710 cfs (based on the FHAD, the peak 100-year
discharge of 640 cfs at FHAD DP 301 appears to include the King’s Gulch drainage
area; however, this should be verified). The model indicates the total flow coming
from these two drainages to this point is approximately 900 cfs.
The revised models have approximately 1098 cfs flowing into Skunk Creek from Bluebell
Canyon Creek and King’s Gulch. The total increase in discharge along Skunk Creek is
630 cfs as a result Bluebell Canyon Creek and King’s Gulch. In order for the discharge
along Skunk Creek to not exceed the effective hydrology, the flow increases along Skunk
Creek were reduced in order to match the effective hydrology total discharges. This was
done as described in the first paragraph on page10.
7. On Page 10, Table 3 of the report please change River Station ID from 11437 to
11847. It appears that Flow Change ID No. 2 was omitted when it should be
included in the table as well. Please provide justification as to how the discharges
were determined at FHAD DP 302. For consistency, the values in this row should
not be bolded as they are not listed as being effective discharges. River Station
1022 associated with FHAD DP is located along Baseline Road and not the main
Skunk Creek flow path. Please include a cross section in the table along Skunk
Creek associated with the flow change. Please change Flow Change Location
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from “Upstream of 29 Street” to “Downstream of 29 Street”. Please change the
River Station ID from 5277 to 4497 and Flow Change Location from “Upstream of
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Street”. Also, to be consistent, the Flow
Euclid Avenue” to “Upstream of 34
Change ID No. 7 row should be bold and include all applicable 500-year discharges
as they were included in the FIS.
The table has been revised.
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8. On Page 16 in the first paragraph, the second to last sentence is not clear. Please
revise this discussion to provide additional clarity.
The text has been revised.
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9. On Page 18 in the first paragraph at the top of the page, revise “27 Street” to “27
Way”.
The text has been revised.
10. On Page 18, please consider revising the downstream boundary condition on the
King’s Gulch reaches to normal depth to be consistent with the other flow paths. It
is standard for FEMA to require using normal depth. The use of tailwater from
receiving streams normally requires justification (which can simply be previous
precedent).
The starting water surface elevations for King’s Gulch have been revised to normal
depth.
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11. On Page 28, the description of the hydraulic model from its upstream limit to 20
Street along Bluebell Canyon Creek does not describe how flows are able to split
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out to the east along the Mariposa-US-16 flow path. Also, the 500-year spill is
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Street to the south along Mariposa Avenue, but not the
mentioned upstream of 15
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100-year spill. Junctions are mentioned at 16 and 17 Streets that distribute the
flow; however, they do not appear to be present in the HEC-RAS model. Also, a
majority of the flow is said to go north and east along Columbine; however, it
appears a majority of flow heads east down Mariposa Avenue. Please revise the
text as necessary.
Report text has been revised.
12. On Page 28 under the “Baseline Spills” section, it states that flows are lost to the
north along Baseline Road but return at the US-36 interchange in the Skunk Creek
model. It does not appear that local topography would support this assumption.
Please justify. Also, this 100-year spill appears to be approximately 90 cfs; a split
flow path or shallow flooding zone may need to be defined for this spill.
The watershed boundary and spill flows north of Baseline Road were discussed with the
City of Boulder and Belt Collins West, who initiated the mapping update. It was agreed
that these flows would predominately return to Skunk Creek further downstream, closer
to Aurora Avenue. However, the flows were requested by the City to be added back to
Skunk Creek at the US-36 interchange to remain consistent with the current effective
FEMA discharges at that location. This decision was believed to be consistent with past
Skunk Creek, Bluebell Canyon Creek, and King’s Gulch Request for Physical Map Revision
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input provided by both the City of Boulder and UDFCD. No additional revisions have
been completed.
13. On Page 29 under the “Broadway to Skunk Creek” section, the discussion
regarding the adding in of flows to satisfy the hydrology of DP 212 is confusing.
Please revise as necessary.
Report text has been revised.
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14. On Page 29 under the “Kings Gulch from the upstream limit to 20 Street” section,
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it mentions that the 500-year floodplain upstream of 15 Street includes Bellevue
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Drive from 15 Street to the Bellevue Drive culvert pipe. The 500-year floodplain
mapping appears to be confined to the main channel in this reach. Please revise
as necessary.
Report text has been revised.
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15. On Page 30 change any references from “22 Avenue” to “22 Street”.
Report text has been revised.
16. On Page 31, the final paragraph describes how flow splits were determined for the
25-, 50-, and 500-year events into the NIST reach by pro-rating the 100-year spill
along the right bank lateral structures. Please provide additional explanation for
this assumption. Also, it states that the discharges were pro-rated down to
Bluebell Avenue which is downstream of the NIST reach. Please provide
clarification.
Based on the original modeling approach and discussions with the City, this method of
split flow determination is considered reasonable. The text has been reviewed and
revised to provide additional clarification.
17. Page 34 indicates the 100-year discharge was increased by 10 percent at Cross
Section No. 7407 (increases from 1,350 cfs to 1,525 cfs, an increase of 175 cfs).
Please provide justification for this increase. It is noted the FHAD hydrology
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indicates that not until Madison Avenue and 35 Street does the 100-year
discharge increase by 520 cfs (1,350 cfs to 1,870 cfs).
This reflects the previous modeling approach and provides a more gradual increase in
discharge. No revisions have been made.
Skunk Creek, Bluebell Canyon Creek, and King’s Gulch Request for Physical Map Revision
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18. On Page 35 under the “Wellman Canal” section at the bottom of the page, the
second sentence is lengthy and confusing. Please revise to provide additional
clarity.
Report text has been revised.
Skunk Creek HEC-RAS Model
19. The HEC-RAS model indicates the downstream boundary condition along the main
flow path is normal depth. It appears that the culverts immediately downstream at
Foothills Parkway could create backwater. Please consider moving the
downstream cross section for the Skunk Creek model downstream of Foothills
Parkway.
The downstream tie-in area with both Bear Creek and Boulder Creek has been revised.
The HEC-RAS model now extends downstream of Foothills and ultimately to Boulder
Creek using modeling taken from the pending Boulder Creek and Bear Creek studies.
20. The lateral structures modeled along the left overbank immediately upstream of
Foothills Parkway (12 total) are modeled using a weir coefficient of 2.4. The report
states in Section 3.5.2 (page 36) that “weirs were coded…using a weir coefficient
of 2.4 to reflect high backwater in the left overbank (Boulder Creek floodplain).”
This assumes concurrent flood peaks. Please verify that these weir coefficients
are reasonable.
The weir coefficients have not been revised as they consider the backwater (from spill
out of Skunk Creek – not from concurrent flood peaks) in the Boulder Creek overbank.
21. Cross Section No. 1635 is being exceeded along the left overbank during the 100-
year event. Consider placing a lateral structure(s) upstream and downstream of
this cross section.
Cross section 1635 has been revised to reflect the ground elevations at the top of the
embankment. The cross section is now contained.
22. It appears that Lateral Structure No. 12535 (Reach 1.020-Innova, located along the
left overbank between Cross Section Nos. 12550 and 12500) spills across the flow
path into Reach 1.010-Inova, which is located along the right overbank. Please
confirm this model configuration is appropriate. Please consider eliminating the
lateral structure as the spill appears to be minimal and mapping the floodplain as a
backwater area.
This configuration reflects the storm sewer system that collects discharges in the left
overbank and then outfalls into the open channel on the east side of Innovation Drive. No
revisions to the model have been made.
Skunk Creek, Bluebell Canyon Creek, and King’s Gulch Request for Physical Map Revision
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23. Both ends of Cross Section No. 12000 are being exceeded during the 100-year
event. Please extend the endpoints of this cross section to contain the flow.
Cross section 12000 has been revised and is now contained.
24. The cross sections along Innovation Drive between Discovery Drive and Colorado
Avenue show 100-year water surface elevations exceeding the left overbank
ground elevations. Please extend the left ends of the cross sections in order to
contain the water surface elevation.
This reach of innovation drive is bounded by large buildings on the left overbank. It is not
necessary to extend the sections as the flow will be adequately contained by the
structures.
25. Cross sections between Euclid Avenue and Colorado Avenue along Skunk Creek
do not appear to be perpendicular to flow streamlines; it appears as if two flow
paths could be modeled through this area. Please review and revise if necessary.
This approach reflects the original modeling efforts. This area has also undergone a 2D
confirmation of split flows that confirmed the original modeling approach.
26. There appear to be a number of areas that have limited or no use of blocked
obstructions and/or ineffective flow areas. Rather, higher assumed n-values
appear to have been used to represent the presence of flow obstructions. This is
not consistent with other areas in the model and may influence the definition of the
CZ and HHZ. Please review, along all flow paths, including Bluebell Canyon Creek
and King’s Gulch, and explain or revise as necessary.
This approach was discussed with the City. With exception to areas where new
modeling was developed, the original modeling approach was maintained.
27. The report (Table 3) indicates the total 100-year discharge at Cross Section No.
6517 should be 1,780 cfs; the model indicates a total flow coming to this point
(before splits) of approximately 1,529 cfs. Also, the report (Table 3) indicates the
100-year discharge should be 2,230 cfs at Cross Section No. 4886; however, the
FHAD indicates that this is the discharge at the outfall. Please revise as
necessary.
These discharge issues were reviewed and the application of the flow was not changed.
The 2233 cfs total occurs somewhere between Madison Avenue and the confluence with
Bear Creek. Given the presence of multiple split flow paths and the tributary basin
partially located both north and south of Colorado Avenue, the total discharge values
were considered reasonable.
Skunk Creek, Bluebell Canyon Creek, and King’s Gulch Request for Physical Map Revision
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28. The cross sections immediately upstream of 29 Street are very tightly spaced
(within approximately five feet in the overbank). Please consider eliminating some
of these cross sections, unless the spacing is necessary for modeling accuracy.
This was done per the original modeling approach and will not be revised.
29. The flow path along Baseline Road crosses over the Skunk Creek hydraulic
baseline, and the lateral spill along the right overbank spills back underneath
Baseline Road. Please clarify the flow splits in this area.
The right overbank spill will enter a multi-use trail underpass and flow north underneath
Baseline Road.
30. Flows that split from Skunk Creek (334 cfs) south along U.S. Highway 36 are
assumed to return to the creek north of Baseline Road. It appears that the local
topography might preclude this from happening. Please review and revise as
necessary. If this is justified, an additional flow path may be required to define this
split.
This reflects original project approach and is based on previous direction provided by the
City of Boulder. This area was reviewed with the City, who elected to not add the
additional flow path.
31. The total 100-year discharge passing beneath Broadway on Skunk Creek is
approximately 1,090 cfs. Was the timing of the hydrographs from FHAD Design
Points 212 and 302 investigated in order to define this peak discharge? It appears
the discharge at this point could be roughly between 1,200 and 1,300 cfs. Please
explain or revise as necessary.
As a result of revisions to drainage basin B-2, there is a portion of that basin that
contributes discharge to Skunk Creek downstream of Broadway. This contribution of
approximately 293 cfs accounts for the noted discrepancy.
32. There are a number of lateral structures in the model that are not optimized.
Please provide justification as to why these structures were not optimized (notes
in the model are also recommended) and justification for the split flows that are
represented.
Some lateral structures were not optimized in order to get the model(s) to converge. Split
flows that are represented are based on vertically extended cross sections and
topography that indicates that the split flow would not immediately return to the main flow
path.
Skunk Creek, Bluebell Canyon Creek, and King’s Gulch Request for Physical Map Revision
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33. There are a number of locations where discharges change across crossing
structures. Please verify modeling results in these cases are appropriate. It is
recommended that discharges remain constant through each crossing.
In these areas it has been assumed that surface discharge will flow from the roadways
and enter the channel on the downstream side of the crossing structure. For this reason
it was common for discharges to change across crossing structures.
Bluebell Canyon Creek & King’s Gulch HEC-RAS Model
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34. Lateral Structure No. 2450 (King’s Gulch – Kings-US-17 Reach) should have the
tailwater set at Cross Section No. 15814 instead of Cross Section No. 15731.
Please revise as necessary.
Discharge that flows through lateral structure no. 2450 will flow into cross section no.
15731. The model has not been revised.
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35. It appears that split flow paths should be considered off of King Avenue along 18
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and 19 Streets. Please review and add flow paths as required.
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The depth of flow that would travel north along 18 and 19 Streets is estimated to be
less than 0.5 feet, which is consistent with the Zone X shaded designation that has been
used in these areas. Additionally, these two flow paths were not identified during
flooding in September 2013.
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36. It appears that several cross sections along Bluebell Avenue east of 20 Street are
angled downstream farther than would be consistent with lines of constant water
surface elevation. Please re-orient these cross sections to be more perpendicular
to the flow (this would apply to BFEs as well).
Due to the split flows in this area and the ditch influence, the cross sections are aligned
as best possible to facilitate reasonable floodplain delineation. The cross sections have
not been revised.
37. Cross Section Nos. 1885, 1936, and 2055 along King’s Gulch have Manning’s n-
values of 0.45. Please provide justification as to the use of such conservatively
high values. Also, please refer to Comment No. 8 in the Skunk Creek HEC-RAS
model comments section concerning the use of flow obstructions and physically
representative n-values.
Manning’s n values at cross sections 1885, 1936, 2055, and 2208 have been reduced to
a value of 0.06. Please note that this change affects the flow over the adjacent lateral
weir and downstream flow distributions which have been revised accordingly.
Skunk Creek, Bluebell Canyon Creek, and King’s Gulch Request for Physical Map Revision
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38. It appears as if there is a flow split occurring along the right overbank between
Cross Section Nos. 5696 and 5828 (37 cfs toward Bellevue Drive) on Bluebell
Canyon Creek; however, the discharge profile along Bluebell Canyon Creek does
not reflect this reduction in flow. Please revise or explain as necessary.
This flow split was identified by the 2D model but is not evident by the 1D model. In an
effort to remain conservative with the main channel of Bluebell Canyon Creek, yet show
the identified flow split, the minor reduction in discharge for flows leaving the main
channel has not been accounted for along the main channel.
39. Based on the flow split occurring between Cross Section Nos. 4282 and 4258 on
the Bluebell Canyon Creek flow path, it appears to be reasonable that the flow
change along Mariposa Avenue should occur at Cross Section No. 3141 (adjacent
to Cross Section No. 4258) instead of at Cross Section No. 3081 (i.e., upstream of
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15 Street). Please revise as necessary.
The discharge increase for Mariposa Avenue has been moved upstream from cross
section 3081 to 3141.
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40. Cross sections in the vicinity of 20 Street and Columbine Avenue do not appear
to be oriented perpendicular to the flow and, in some cases, cross over one
another, or are nearly concurrent with one another. The 5440 BFE also crosses
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Cross Section No. 11998 on 20 Street. Please revise.
The cross section layout in this area is complicated by the Anderson Ditch, junction of a
split flow reach, and the start of another split flow reach. As a result, the cross sections
were aligned as best possible given the modeling and topographic constraints.
41. It does not appear that the discharge profile in the HEC-RAS model along Bluebell
Canyon Creek matches the profile provided in the report. For example, the 100-
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year discharge along Mariposa Avenue just east of 19 Street is 273 cfs, and the
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discharge one block north along Columbine Avenue just east of 19 Street is 121
cfs. The total discharge at this point is 394 cfs, and according to the table, the
discharge at Flow Change ID No. 3 should be 590 cfs. Please revise or explain as
necessary.
Upon further review of the hydrology for drainage basin B-2 (draining to FHAD design
point 212) it was determined that the area north of Baseline Road does not contribute to
Bluebell Canyon Creek upstream of US Highway 36. As a result, B_2 inflow node has
been adjusted and the B_3 inflow node has been removed. The 394 cfs value is valid
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from 15 street east to Broadway.
Skunk Creek, Bluebell Canyon Creek, and King’s Gulch Request for Physical Map Revision
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st
42. The lateral structures along Baseline Road between 21 Street and Broadway are
not optimized. Please explain how these splits are determined. Also, adding notes
within the model is highly recommended.
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All lateral structures along Baseline Road between 21 Street and Broadway are now
optimized and reflect the split flows that occur in this area.
43. The 100-year flow splits to the north from the main Bluebell Canyon Creek flow
path to the upstream end of Columbine Avenue do not match. It appears as if
there is 70 cfs splitting to the north (121 cfs to 51 cfs), while the Columbine flow
path has 65 cfs. Please revise as necessary.
At this location, the discharge values have been based on a 2D model and compare
within 5 cfs (4% of total flow). This difference was not further refined.
44. The flow is reduced from approximately 80 cfs to 20 cfs during the 100-year event
between Cross Section Nos. 11100 and 11030 along Baseline Road. Is there a flow
split occurring to the north? If so, please explain how the split was determined.
Yes, a flow split occurs at this location. Discharge values are now based on lateral weir
spills that are now optimized accordingly.
45. The 100-year flows at the intersection of Baseline Road and Broadway do not seem
to maintain continuity. The model indicates there is approximately 20 cfs along
Baseline Road both upstream and downstream of Broadway, whereas the
upstream end of Broadway has 150 cfs, directly downstream of Baseline Road.
The 100-year WSEL at Cross Section No. 14900 is also nearly 0.3 feet higher than
at Cross Section No. 10725 immediately upstream. Please revise as necessary.
This is a result of the B_4 inflow location. No model revisions were completed.
46. The source of an additional 70 cfs along Broadway between Baseline Road and
Columbine Avenue during the 100-year event is not apparent. Please explain.
This errant addition of 70 cfs along Broadway between Baseline Road and Columbine
Avenue has been fixed. The B_4 inflow is the only discharge increase in this general
vicinity.
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47. According to the 100-year discharges in each reach, the total flow that could
potentially reach Broadway (assuming no splits north off of Baseline Road and no
splits south off of Mariposa Avenue toward Bluebell Avenue) is 616 cfs (Bluebell
Canyon Creek only). Assuming that the split of 37 cfs off of Bluebell Canyon Creek
onto Bellevue Drive should be accounted for, the total discharge would drop to 579
cfs. Table 1 indicates the total discharge should be 740 cfs. Please revise
accordingly.
This discrepancy is the result of recent changes to Basin B-2 in order to more accurately
account for the portion of the basin north of Baseline Road that will not be accounted for
until downstream of US Highway 36. Table 1 has been revised and Figures 3.1 and 3.2
have been created to provide a map showing the flow increases and discharges along
the various split flow reaches of Bluebell Canyon Creek. Please note that the flow
profiles reflect total flow and may not necessary accurately reflect discharge within a
given split flow reach.
48. The residual 100-year discharge along Baseline Road is approximately 20 cfs, and
the flows in front of the Basemar Shopping Center are approximately 41 cfs. The
discharge east of this intersection is approximately 10 cfs rather than what would
appear to be 61 cfs. Please explain or revise as necessary. Further downstream,
the flows tie into the Skunk Creek model, and the flow at the upstream end of this
reach (Cross Section No. 1548) is 225 cfs. It appears continuity may be an issue at
this location. Please review and revise.
Due to minor changes the residual discharge along Baseline Road is now approximately
23 cfs and the flows in front of the Basemar Shopping Center are approximately 29 cfs.
The discharge east of the intersection of these two split flows has been revised to 52 cfs.
Further downstream the discharge increase to 225 cfs is a result of an increase in
discharge as a result of flows that originate or spill into the drainage basin on the north
side of Baseline Road. In order to match the FEMA flows along Bluebell Canyon Creek
and ultimately Skunk Creek, the full discharge has been returned to the model at US
Highway 36, as discussed previously.
49. Cross Section Nos. 1570 and 1520 along Columbine Avenue have n-values for the
street portion of the cross section of 0.1. Please provide justification for this
roughness value or revise as necessary.
The Manning’s n values have been revised to reflect a value of 0.03 within the roadway
sections in similar fashion to sections upstream and downstream.
50. Cross Section No. 2793 has a negative surcharge (-0.2 ft) in the conveyance zone
plan. Please revise as necessary.
This section does not have floodway encroachment into the effective conveyance area.
Also note that the change in energy grade is +0.49 feet.
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Floodplain Workmaps
51. According to the HEC-RAS model, 100-year flows begin spilling over the left
overbank on the main Skunk Creek flow path downstream of Cross Section 1437.
Figure 4.9 depicts the 100-year floodplain boundary extending past this point to
Cross Section 1237. Please revise as necessary.
This area has been revised to reflect the spill downstream of cross section 1437.
52. The 100- and 500-year floodplain mapping limits along the split flow path 1.020-
Innova, in particular between Discovery Drive and Colorado Avenue, are mapped
against adjacent structures. Please use the bare earth topography to map the
floodplain limits.
Given the size of these structures and the mapping source (LiDAR) there is not
reasonable bear earth topography available for use. Additionally, the size of structures is
such that they will provide significant containment of the floodplain. In order to remove
any ambiguity, the floodplain mapping limits were adjusted in order to clearly show
buildings that are impacted by the adjacent floodplain boundary.
53. General mapping note: BFEs need to be coincident with the 100-year floodplain
limits as well as the associated contour elevation unless being tied to the DEM. As
an example, BFE 5255 on Skunk Creek, immediately upstream of Cross Section
No. 1968, extends past the 100-year floodplain limit (as well as the 5255 contour).
Other examples include the 5590 BFE (King’s Gulch; ties to the 5591 contour on
one side) and the 5595 BFE (King’s Gulch; extends past the 5595 contour on one
side and doesn’t reach it on the other).
This issue (generally less than 2 feet in size) appears to result from the use of survey
data in place of mapping.
54. The 5490 BFEs along Bluebell Avenue and King Avenue should tie to the
floodplain limits and not extend into the shallow flooding area.
These BFEs have been revised.
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55. It appears that Shaded Zone X should be mapped between 19 Street and 22
Street and Mariposa Avenue and Bluebell Avenue. Please review and revise as
needed.
This area has been revised to reflect a Zone X shaded designation.
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56. There are a number of locations where cross section alignments intersect one
another on differing flow paths, in particular at the intersection of King Avenue and
Skunk Creek. Please orient the cross sections to not intersect.
The cross sections were aligned as best possible given the modeling and topographic
constraints. This issue is generally a result of the alignment of multiple flow paths where
there is not a reasonable approach to alternative orientation.
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57. The BFEs along and south of Columbine Avenue between 18 and 19 Streets are
generally not parallel to the adjacent cross sections and some cross between flow
paths. Also, as an example, the 5470 BFE is shown crossing the 5472 contour
elevation. Please adjust as necessary.
The orientation of the BFEs reflect the condition of discharges transferring form the south
to the north. The 5470 BFE is shown as crossing the 5472 contour in order to avoid
showing a small island in the middle of the floodplain.
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58. A detailed floodplain with BFEs is mapped along Columbine Avenue between 20
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Street and 22 Street at a 100-year discharge of 13 cfs; however, a detailed
floodplain is not mapped along Bellevue Drive and Mariposa Avenue upstream of
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15 Street for a 100-year discharge of 37 cfs (mapped as Shaded Zone X). Please
explain or revise as necessary.
The 13 cfs along Columbine has been shown as detailed study as it eventually receives
additional discharges for a total flow of 58 cfs. The 37 cfs along Mariposa Avenue has
been mapped as Shaded Zone X as a result of continuously shallow flooding and a lack
of discharge increase.
59. The 100- and 500-year floodplain limits do not extend upstream through Cross
Section No. 20270 on the Skunk Creek – 7.122 NIST S flow path. It appears as if
there is a split occurring along the main Skunk Creek flow path into this flow path.
Also, please add a gutter line between the Skunk 7.121 NIST N and 7.122 NIST S
flow paths.
The delineation for 20270 reflects the original modeling approach and has not been
revised. Similarly, the gutter line has not been added as the floodplains are joined.
60. Please indicate that minor flows would leave the system east of the intersection of
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29 Street and Baseline Road. One option would be to use dashed floodplain
boundaries with a flow arrow heading east.
The flows leaving have been determined to be insignificant and shallow enough to not
warrant additional designation. Likewise, the full discharge has been accounted for
within Skunk Creek to remain conservative. No revisions have been completed.
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61. BFE 5335 at the intersection of 29 Street and Skunk Creek crosses two separate
flow paths, crosses Cross Section 7489, and runs parallel to the flow split going
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north down 29 Street. BFEs 5300 and 5305 have similar orientation issues.
Please revise as necessary.
Given the urban shallow flooding condition, this has been a challenge to depict. The
BFEs have been drawn to best illustrate the respective flood risk and also to reflect the
major flow directions. In an effort to keep the mapping simple, extensive use of gutter
lines has not been used.
62. Please show the 500-year floodplain boundary on the south side of Mariposa
th
Avenue west of 19 Street.
This area has been designated as Zone X shaded.
63. Please add flow path identification on the work maps.
Separate flow path identification work maps have been prepared. Please see figures 4
and 5.
Please let me know if there is any additional information needed to clarify our responses to the
above review comments.
Sincerely,
Brian LeDoux, P.E., CFM
ICON Engineering, Inc.
Skunk Creek, Bluebell Canyon Creek, and King’s Gulch Request for Physical Map Revision
Peer Review Comment Response
14
ICON Engineering Inc.
RH7X
39th St
Cordry Ct
22nd St
39th St
Cordry Ct
29th St
27th Wy
20th St
2055
5515
2208
16th St
157312408
2527
15th St
4019th St17317
17458
1342
1947
1465
17604
2136
1547
17675
5485
2313
5490
1829
364315166
5505
5505
2055
5515
2208
5520
157312408
2527
15th St
5390
0181
319
0923
5430
1099
1319
5440
17038
1522
1626
17174
1106
5460
172117246
2739
17317
17458
1342
1947
1465
17604
2136
1547
17675
5485
2313
5490
1829
3643
15166
5505
5505
2055
5515
5360
28th St
28th St
5360
5390
0923
1099
21st St
5420
1319
5430
5440
2469
17038
1522
1626
17174
172117246
2739
4017317
17458
1947
54655470
32nd St
31st St
30th St
5325
631
7234
5325
726
5340
7840
28th St
5360
5365
36th St
238
6.49
140.5
6.79
278
180
45
304
212
83
252
5926
373
274
124
7.99
5995
151
413
315
8.42
441
345
202.5
31st St
9.02
240
395
9.64
455
308
347
10.29
518
642
546
575422
10.88
30th St
5305
190
360.5
472
631
5325
726
5315
5320
5255
5260
5245
Attachment C - Public Comments
ǡ
ǯ
Open House Date:
Aug. 18, 2014
Open House Meeting Location:
Municipal Building Lobby
Number of attendees that signed-in:
23
Staff in Attendance:
Robert Harberg Katie Knapp Kristin Dean
Laurel Olsen-Horen Douglas Sullivan
Public Comments:
1.Location: 2042 Baseline
Commenter: Property owner (Ben Chancellor; Christina Jurgens)
Comment: Did not see flooding in September 2013 and do not feel that the high hazard
designation iswarranted; question split values for Mariposa vs. Columbine
Response: The high hazard zone delineations have been refined based on a review of
adjacent grades. Adjacent to the structure at 2042 baseline, the delineation was revised
such that the structure sits just outside of thehigh hazard zone. Split flow values for
Mariposa and Columbine are being re-evaluated using 2Dmodeling to see if the September
flood event can be more closely replicated in the modeling. It should be noted that the
September 2013 flooding reflected a lower intensity and longer duration storm compared
to the regulatory 100-year design storm that is a significantly higher intensity but shorter
duration storm. This difference in storms can result in significant differences between the
regulatory 100-year floodplain mapping and what was experienced in the September flood
event.
2.Location: Area south of Baseline Road between 20th and Broadway
Commenter: Several property owners
Comment: Flooding in September 2013 was confined to streets; no flow behind homes;
water did not appear to be originating from Bluebell Canyon Creek proper.
Response: Split flow values for Mariposa and Columbine are being re-evaluated using
2Dmodeling to see if the September flood event can be more closely replicated in the
modeling. It should be noted that the September 2013 flooding reflected a lower intensity
and longer duration storm compared to the regulatory 100-year design storm that is a
significantly higher intensity but shorter duration storm. This difference in storms can result
1
Attachment C - Public Comments
in significant differences between the regulatory 100-year floodplain mapping and what
was experienced in the September flood event.
3.Location: 22nd and Mariposa Avenue
Commenter: Several property owners
Comment: Flows traveling east on Mariposa turned north on 22nd Street and continued to
Columbine Avenue; this is not shown as 100-year flooding.
Response: This flow path has been added to the documentation of the September flood
event. The portion of 22nd Street between Mariposa and Columbine is shown as shallow
flooding (Zone X) for the proposed floodplain. The proposed floodplain mapping is this area
is being re-evaluated.
4.Location: 19th and Mariposa Avenue
Commenter: Property owner
Comment: structure at south east corner is shown in the 100-year floodplain but did not
experience damage during the September 2013 event; please review assumptions here.
Response: Split flow values for Mariposa and Columbine are being re-evaluated using
2Dmodeling to see if the September flood event can be more closely replicated in the
modeling. It should be noted that the September 2013 flooding reflected a lower intensity
and longer duration storm compared to the regulatory 100-year design storm that is a
significantly higher intensity but shorter duration storm. This difference in storms can result
in significant differences between the regulatory 100-year floodplain mapping and what
was experienced in the September flood event.
5.Location: 955 Quinn Street
Commenter: Property owner (Lee Payne)
Comment: Structure does not show as impacted on floodplain maps (tree cover issue?);
how was floodplain delineated at corner of Denton Avenue and Quinn Street.
Res
ponse: Due to the large amount of tree cover, the structure was inadvertently excluded
from the proposed floodplain map exhibit. The maps have been corrected to show the
-ye
principal structure located outside of the proposed 100ar floodplain.
6.L
ocation: 3130 Aurora
Commenter: Property Owner
Comment: It seems like the HHZ could be the result of a small depression that we may not
want to include
in the mapping.
Response:
7.Location: 1700 Bluebell
Commenter: Property Owner (Bill Mooz)
Comment: Structure is shown as in proposed floodplain but was not impacted by
September 2013 event;wants to know why actual data was disregarded.
2
Attachment C - Public Comments
Response: The September 2013 flooding reflected a lower intensity and longer duration
storm compared to the regulatory 100-year design storm that is a significantly higher
intensity but shorter duration storm. This difference in storms can result in significant
differences between the regulatory 100-year floodplain mapping and what was experienced
in the September flood event. Split flow values for Mariposa and Columbine are being re-
evaluated using 2Dmodeling to see if the September flood event can be more closely
replicated in the modeling.
8.Location: 1849 Mariposa Ave,
Commenter: Property Owner (Steve Brown, Guen Simons)
Comment: Water from Bluebell creek did not flow to Mariposa. It flowed down the Bluebell
drainage but primarily to the north along 19th Street and down Columbine.
Response: Split flow values for Mariposa and Columbine are being re-evaluated using
2Dmodeling to see if the September flood event can be more closely replicated in the
modeling. It should be noted that the September 2013 flooding reflected a lower intensity
and longer duration storm compared to the regulatory 100-year design storm that is a
significantly higher intensity but shorter duration storm. This difference in storms can result
in significant differences between the regulatory 100-year floodplain mapping and what
was experienced in the September flood event.
9.Location: 2100 Baseline
Commenter: Property Owner (Jamie Karpohl)
Comment: a) There were no eastbound flows observed on Columbine west of 20th Street.
b) The flooding at 20th and Columbine originated from the Anderson ditch on the north side
of Columbine. This waterflowed through properties to the north-east and down the
Columbine North alley towards 21st. At 21st the flows split - continuing down the alley and
heading north towards Baseline. c) During the flood, there was no flow observed coming
down Columbine west of 20th. The only flows observed in Columbine were from Anderson
ditch on the north side of the street. When I visited the location of Bluebell Canyon Creek at
th
St. on the morning of September 14th, I observed all of the flow heading down
15
Mariposa. I did not observe any man-made diversions at this location.
Response: a) The city has received conflicting information about the flooding observed
thth
and 20 Streets. At this time the flood extent
along Columbine between 19
th
documentation shows this area as having flows that came north from Mariposa along 19
Street and then continuing east on Columbine. The documentation of the September 2013
flood extents will continue to be refined as additional information is received.
b) Split flow values for Mariposa and Columbine are being re-evaluated using 2Dmodeling
to see if the September flood event can be more closely replicated in the modeling. It
should be noted that the September 2013 flooding reflected a lower intensity and longer
duration storm compared to the regulatory 100-year design storm that is a significantly
higher intensity but shorter duration storm. This difference in storms can result in
significant differences between the regulatory 100-year floodplain mapping and what was
experienced in the September flood event.
3
Attachment C - Public Comments
Public Hearing:
WRAB Meeting, Aug. 18, 2014
Meeting Location:
Council Chambers
Public Comments:
1.Steve Brown, Guen Simons - Water from Bluebell creek did not flow to Mariposa. It flowed
th
down the Bluebell drainage but primarily to the north along 19 Street and down
Columbine.
2.Lee Payne - My home does not show up as either added, removed or remaining in the 100
year floodplain on the “structures affected proposed 100 year floodplain”. I believe this is
due to the dense tree cover on my lot. The buildings on this lot look to be un-included in the
100 year flood zone, but it is unclear. The grading and slopes on my lot are high from the
street and I believe the new mapping to be close to reality in that the homes are excluded.
and what the base flood
Can you please contact me to clarify if the structures are excluded
elevation is in this area? There is also no information on sections or elevations for this lot on
the city’s website. Thank you!
Public Hearing:
WRAB Meeting, Sept. 15, 2014
Meeting Location:
Council Chambers
Public Comments:
1.Christina Jurgens – Concerns are with the Bluebell and that there were no diversions, which
isn’t reflected accurately in the mapping presented. Question is if a lot of water falls inthe
area, water will not flow uphill to 19th street and over Columbine if it’s natural direction is
downhill. She would like for this to be considered when moving forward with the
amendment.
2.Bryan Boots – Owns a home at 20th and Columbine, which is in anewly designated hazard
zone. He was completely unaware of the changes in zoning and is feeling like he is coming
to the conversation late. Questions the assumptions that are going into this decision
making and having a hard time reconciling the recent studies with what he actually
experienced last September. He would like to better understand the next steps in the
process regarding what is decided. It doesn’t seem reasonable to put the burden on
residents. He is requesting better, more effective outreach to citizens.
3.Tim Fuller-Rowell – Lives on Columbine Avenue, which is affected by the new floodplain,
which now makes up half of his property. Increase in the water table flooded the basement.
Flow down Mariposa didn’t affect us. Rock dam broke causing a flash flood and persistent
rainfall and wonders if that was factored into the analysis, but didn’t see any major flow on
4
Attachment C - Public Comments
Columbine. Wants to understand the actual impact of flood to his property and physical
reasons why it is now included on the floodplain. What is the process for deciding how the
new boundaries are drawn and decided? Premature to start approving a new floodplain
before the previous event is fully understood and would like the city to have more
interaction with the people who are actually affected.
4.Jamie Krapohl – Property owner affected by the proposed flow split changes at 15th is his
major concern. He didn’t observe what is being shown on the maps and feels there is a lack
of correlation in how the split affects these three blocks. On the Saturday of the flood, he
was at 15th and Mariposa and didn’t observe any diversions that were put into place by
residents. The flooding on his corner was due to the Anderson Ditch overflowing, which is
not represented in the changes. Since the open house, he has reached out to neighbors,
but there are many renters around his property. He contacted three other property owners
and informed them of the recent flood mapping changes. Feels that neighbors were not
aware of these new changes. Concerned with the accuracy of the models, based on
observations from walking around the neighborhood and what is being reflected in the
updated maps. He feels this just doesn’t make sense.
5
22nd St
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RH7X
C I T Y O F B O U L D E R
WATER RESOURCES ADVISORY BOARD
AGENDA ITEM
MEETING DATE: May 18, 2015
AGENDA TITLE:
Public hearing and consideration of a recommendation to City
Council regarding the South Boulder Creek Major Drainageway Flood Mitigation
Plan.
PRESENTER/S:
Jeff Arthur, Director of Public Works for Utilities
Tracy Winfree, Interim Director, Open Space and Mountain Parks
Annie Noble, Acting Principal Engineer for Flood and Greenways
Kurt Bauer, Engineering Project Manager
Kristin Dean, Utilities Planner II
EXECUTIVE SUMMARY:
A Recommended Plan for flood mitigation along South Boulder Creek was presented to
the public, Water Resources Advisory Board (WRAB), Open Space Board of Trustees
(OSBT) and City Council at a Study Session in 2014. The Recommended Plan was
comprised of three phases:
Phase I: Regional detention facility at US 36;
Phase II: West Valley improvements; and,
Phase III: Arapahoe Avenue detention.
In 2014, the WRAB and City Council were generally supportive of the mitigation
proposed under Phases II and III. The OSBT also indicated their support for Phases II
and III as it was not seen to have effects on city open space properties. However,
significant concern was voiced by both boards and by City Council regarding potential
environmental impacts, including those to Open Space and Mountain Parks (OSMP)
lands from the proposed US 36 regional stormwater detention facility (Phase I). As a
result, staff was directed to evaluate other options, including potential use of a larger
portion of the Univers
environmentally sensitive areas.
Since then, six additional options were developed for US 36 detention, all designed to
prevent the overtopping of US 36 during a 100-year design storm and reduce flooding
impacts downstream and each with fewer impacts to OSMP than the original proposal.
This memorandum presents the US 36 regional detention options, a comparison of
potential impacts to OSMP and CU lands and a summary of potential next steps. Staff is
recommending that the Phases II and III concepts remain unchanged in the mitigation
master plan and that Phase I be accomplished using Colorado Department of
AGENDA ITEM #5 PAGE 1
Transportation (CDOT) Right of Way (ROW) and CU Campus South (Option D) for
construction of a regional stormwater detention facility at US 36. In this alternative, the
berm would be located within the existing CDOT right of way, and, with the exception of
potential temporary impacts from construction of the berm, OSMP lands would only be
affected when stormwaters are retained. Each of the additional options have a greater
2014. However, while CU
prefers the 2014 plan, they have also indicated they are willing to discuss use of their
land to facilitate the implementation of Option D for regional detention.
STAFF RECOMMENDATION:
Staff requests Water Resources Advisory Board consideration of this matter and
recommends action in the form of the following motion:
The Water Resources Advisory Board recommends that City Council accept
the South Boulder Creek Major Drainageway Flood Mitigation Plan including
Option D (single berm using Colorado Department of Transportation (CDOT)
Improvements as the recommended comprehensive alternative to mitigate flood
risks associated with South Boulder Creek.
COUNCIL FILTER IMPACTS:
Economic: A total of 700 structures (442 within city limits) and approximately 1,200
dwelling units (962 within city limits) are located within the 100-year South Boulder
Creek floodplain. A risk assessment completed in June 2009 estimated a 100-year
1
event would result in $215 million in damages. South Boulder Creek (SBC) had the
drainageways. Approximately 362 structures (893 dwelling units) within the city
limits would no longer be located in the 100-year floodplain if the study
recommendation is constructed (approximately 80 structures would remain in the
floodplain within city limits under the recommended plan). Structures removed from
the floodplain would be less likely to be damaged from a flood and would also benefit
from no longer being subject to paying for flood insurance.
Environmental: One of the Boulder Valley Comprehensive Plan general policies
space preservation. OSMP land within the
project area has some of the highest ecological values in the Boulder Valley. The
project area on OSMP lies entirely within the South Boulder Creek State Natural
Area (SBCSNA) which was designated by the State of Colorado in recognition of the
state-wide significance of this exceptional riparian and floodplain ecosystem
- Tresses Orchid (ULTO) habitat, tallgrass prairie,
wetlands, habitat for declining grassland and riparian bird species, habitat for
declining amphibians such as the Northern Leopard Frog, and habitat for declining
native fish. Tallgrass prairie is considered one of the most endangered plant
1
This estimate includes properties in the city and the county.
AGENDA ITEM #5 PAGE 2
communities in the world and OSMP land in the project area contains some of the
highest quality remaining tallgrass prairie in the state and the region. Additionally,
federally threatened plant species. This area is also managed as part of one of the
oldest and most productive agricultural landscapes on city open space. While
previous flood mitigation options would have directly and permanently impacted
these resources, construction of the recommended regional detention facility berm at
US 36, Option D, has fewer impacts on OSMP lands and associated resources.
Temporary impacts to OSMP lands may be necessary for the construction of the
berm. In times of flooding, a portion of Open Space lands behind the berm will be
inundated, depending on the magnitude of the storm, and sediment deposition is
likely to occur. It should be noted that this area is currently in the 100-year
floodplain, which could result in inundation and sediment deposition without the
berm. However these effects are likely to increase by the construction of the berm.
Newly deposited sediments will require management to avoid the establishment and
spread of invasive plant species and habitats impacted by additional sediment
deposition may require restoration.
Social: The flood hazards associated with SBC are a significant risk to life, property
and business. The SBC floodplain includes hundreds of residential structures,
affordable housing, senior housing, medical facilities, and numerous businesses. In
addition, federal highway US 36 overtops during major storm events, eliminating use
of a major thoroughfare into and out of the city. While construction of the study
recommendation would temporarily cause disruption to local residents, businesses,
and transportation routes, mitigating these hazards would further social
sustainability goals and benefit a diverse set of community stakeholders by protecting
them from the significant damage which can be caused from a large flood event.
OTHER IMPACTS:
Fiscal: Implementation of the study recommendations is estimated to cost
approximately $46 million for all three phases. Funding in the 2015-2020
Department of Public Works Utilities Division CIP budget for this project is
$11,750,000. Staff will be recommending increasing the budget in the 2016-2021
CIP by $15 million (in 2018) to a total of $26,750,000. The project could be
constructed in phases with each phase estimated to cost from $11 - $25 million. The
city would also seek grants to fund this project.
Staff Time: Time for completing the study is included in existing work plans.
However, implementation of the recommended option will require additional staff
time from multiple city departments including Public Works, Comprehensive
Planning & Sustainability, Open Space & Mountain Parks, and Parks & Recreation.
BOARD AND COMMISSION FEEDBACK:
Conceptual alternatives were first presented to WRAB in 2010 with a recommendation
from the Board to move forward with four of nine alternatives. The Open Space Board
of Trustees was updated in 2010 by staff. A staff recommendation was presented in
August 2014 to both WRAB and the Open Space Board of Trustees (OSBT), resulting in
the following motions:
AGENDA ITEM #5 PAGE 3
OSBT 2014 Motions:
stream
unanimously.
component which may have lesser potential for environmental impacts. The motion
passed unanimously.
Make a statement to City Council: The Board believes that constructing a regional
detention facility at US 36 would require a significant disposal of Open Space lands,
which would be subject to all applicable Open Space charter provisions. The motion
passed unanimously.
Motions passed 4-0, Dunbar absent.
WRAB2014 Motions:
recommended alternative to mitigate flood risks associated with South Boulder
Creek.
alternative only after looking at alternatives which may have lesser potential for
environmental impacts, and which may provide faster and less costly opportunities
for equivalent mitigation in that area, such as use of CU property detention, private
property detention, and eminent domain options.
The motions passed unanimously (5-0).
A summary of the South Boulder Creek flood mitigation project along with Board
recommendations were presented to City Council at a Study Session in September 2014.
City Council supported development of additional alternatives involving CU South to
reduce potential environmental impacts.
PUBLIC FEEDBACK:
Conceptual alternatives were initially presented at a public meeting in March 2010.
Refined alternatives were then presented at a second public meeting in September 2010.
A public open house was conducted just prior to the August 18, 2014 WRAB meeting to
present the recommended plan and answer questions. Two OSBT meetings were also
held in 2014 and there were public comments at both meetings.
ents in the Frasier
Meadows area, has met with several City Council members, several WRAB members,
and city staff. They also presented a 15-minute video to the OSBT at April 8,
2015 meeting. Approximately 65 residents from the Frasier Meadows area attended the
April 27, 2015 WRAB meeting. Several residents spoke at the meeting and also
presented a video of the 2013 flood.
AGENDA ITEM #5 PAGE 4
A meeting with the OSBT was held on May 13, 2015. Prior to that meeting, staff was
available to provide information about the seven options for providing regional detention
at US 36.
BACKGROUND:
In the mid-1990s, CU evaluated the purchase of land located at US 36 and Table Mesa
Drive. During this evaluation, inaccuracies in the 1986 regulatory flood mapping were
discovered. Studies commissioned by the city and the Urban Drainage and Flood Control
District (UDFCD) revised the 100-year floodplain and estimated that a 100-year storm
event would result in approximately $215 million in damages in the South Boulder Creek
drainage basin. During the 2013 flood, South Boulder Creek overtopped US 36.
Reported property damage in the South Boulder Creek floodplain was the greatest of all
the South Boulder Creek Major Drainageway Flood Mitigation Project web site
(www.southbouldercreek.com) and in the study report (Draft South Boulder Creek Major
Drainageway Plan).
The South Boulder Creek Flood Mitigation Planning Study began in early 2010 and is
being funded by the city and the UDFCD. The study, completed by an engineering
consulting firm, focused on developing and evaluating alternatives to mitigate flood
hazards affecting structures and areas within the current incorporated city limits,
Attachment A).
primarily within the West Valley area (see
Conceptual alternatives which were initially developed included a wide range of flood
mitigation measures. These concepts were then presented at a public meeting and to the
WRAB in 2010. The concepts were subsequently screened based on input received at the
meeting, hydraulic modeling and field visits. The results were used to formulate 15
alternative plans. Concept-level sizing, configurations and costs were developed for each
of these 15 plans along with an estimate of likely benefits and environmental and social
impacts. From
alternatives were presented at a second public meeting and to the WRAB in 2010. The
WRAB recommended moving forward with the following four alternatives:
1.Maintaining the status quo;
2.High Hazard Zone mitigation and critical facility protection;
3.Regional detention at US 36 with downstream improvements; and
4.Distributed regional detention.
In 2014, a draft recommended plan was presented to the public, WRAB and OSBT and to
City Council at a Study Session. The recommended plan included the following phases:
1.A regional stormwater detention facility at US 36;
2.West Valley improvements including a stormwater detention facility at or near
Manhattan Middle School, a small stormwater detention storage area at the
intersection of Foothills Parkway and Baseline Road, and placing a segment of
Dry Creek No. 2 Ditch in a 72-inch diameter pipe;
3.A stormwater detention facility located at Flatirons Golf Course.
AGENDA ITEM #5 PAGE 5
Both Boards made motions to recommend that City Council accept the second and third
phases of the recommended plan but did not support the Phase I regional detention
concept without first evaluating other options to reduce environmental and other Open
Space impacts. Additionally, City Council directed staff to involve CU in discussions to
develop a US 36 regional stormwater detention facility which would use more of their
land in order to effectively reduce environmental and other Open Space impacts (see
Board and Commission Feedback section above).
In response to the direction given by council, six new options for detention at US 36 have
been developed. From a technical aspect, all options function to effectively mitigate
flooding from South Boulder Creek in the same capacity. Construction of all the phases
of the recommended alternative would eliminate overtopping of US 36 and subsequent
flooding in the West Valley during a major storm event and all of the options reduce
impacts to environmental resources and to Open Space compared to the 2014
recommended plan.
City Utilities and OSMP staff met with CU and on several occasions to discuss these
options and to obtain their feedback. In those meetings, as well as at the 2014 public
meetings, CU has stated they are willing to consider use of a portion of the CU South
parcel for flood mitigation. In addition, staff has also met with CDOT to discuss an
option that would use existing ROW. CDOT has stated that it would be willing to work
with the city to develop an agreement for use of existing ROW for this project.
The CU-South Boulder Campus property consists of 302 acres. This property is located
outside of city limits in Boulder County. CU developed a conceptual master
plan for this property identifies
areas for building potential, flood storage, natural areas, ponds, and access points. This
plan has not gone through any city review processes, nor has it been endorsed by the city.
The 2010 Boulder Valley Comprehensive Plan (BVCP) currently designates the majority
of CU South parcel as open space (214 acres) but also includes low- and medium density
residential designation (27 and 67 acres, respectively). The property is located in Area II
which are lands where the city anticipates future annexations. If City Council supports a
flood mitigation alternative that requires land use discussions with CU, it is anticipated
that those discussions would be integrated into the BVCP update that is currently
underway.
ANALYSIS:
Based on feedback from the 2014 public process, six new and very conceptual options for
stormwater detention at US 36 have been developed. As a result, engineering features
and anticipated resource impacts presented in this memorandum are master planning
level, but all of the options would prevent the overtopping of US 36 from a 100-year
design storm. To avoid confusion in relationship to previously considered flood
mitigation alternatives, the seven concepts for providing stormwater detention at US 36
are labeled as Options (A-G). Option A is the concept presented in 2014.
The options are variations of single and dual berm detention systems. Three dual berm
detention options have been developed that include varying degrees of fill and excavation
(Options E, F, and G). The dual berm detention system would require breaching the
AGENDA ITEM #5 PAGE 6
existing CU South levee and constructing an open channel segment within the CU South
parcel. Staff has concerns with these options because debris could block the breach in the
levee which would then prevent water from reaching the secondary detention basin.
Three options have been developed that modify the single berm system (Option A)
presented in 2014 (Options B, C, and D). These options also vary in the degree of fill
and excavation. It should be noted that only Option A (the 2014 option) impacts
Meadow Jumping Mouse (PMJM) critical habitat along
South Boulder Creek. However, all other options would impact habitat occupied by
PMJM. Impacts to PMJM habitat from Option D have already been mitigated by CDOT.
Attachment BTable 1.0
illustrates Options A through G. presents a comparison of
analysis factors for the options including environmental impact.
Table 1.0: Summary Comparison of Conceptual Stormwater Detention Options Upstream of US 36
Green = lowest impacts of options compared
Yellow = medium impact relative to other options compared
Red = greatest impact of options compared
Total
Total Berm Maximum
Impacts Total Est.
impacts to Berm Est. Cost Est. Benefit
Option to CU Detention on Benefit to
OSMP Height ($millions) ($millions)
1 2
ParcelOSMP(acres) Cost Ratio
(acres) (feet)
(acres)
A 2014 Option 56 5 35 34.5 24 26.5 1.1
B - Single Berm with
90 2 5 27.5 21.5 26.5 1.2
Excavation
C Single Berm with
80 3 17.5 30.5 22.5 26.5 1.2
Excavation and Fill
D Single Berm
79 0 19 30.5 22 26.5 1.2
CDOT ROW
E- Dual Berm no
3
142 1 3.5 26.5 26 27 1
Excavation
F Dual Berm with
100 2 5 27.5 31 27 0.9
Excavation
G Dual Berm with
99 0.5 8.5 28.5 34.5 27 0.8
Excavation and Fill
1 Includes berm footprint and detention storage area
2 Includes only the storage pool area, not the current 100-year floodplain area
3 The dual berm options do not reduce the floodplain downstream, but do reduce the flood depth in certain
locations. Thus, the additional benefits from the dual berms reflect a decrease in damage from flooding,
but it is still assumed that the structures in this area do experience some damage.
CU has stated that their preferred regional detention plan is Option A because it uses the
least amount of university land compared to other options. CU has expressed an interest
in working with the City to identify potential sites on their property where environmental
impacts associated with Option A could be mitigated and additional enhancements could
potentially be provided. However, staff does not believe that this approach is consistent
with prior direction from Council and feedback from the boards. While Option D does
option. CU is also open to discussing Option G, but staff does not recommend any dual
berm configurations due to their cost, visual impacts, and relatively low benefit to cost
ratio.
AGENDA ITEM #5 PAGE 7
Staff recommends including Phases 2 and 3 unmodified as conceptually presented in
2014 in the final mitigation plan. Staff also recommends moving forward with Option D
(single berm using CDOT Right of Way) as the concept for providing regional
stormwater detention to prevent overtopping of US 36 during a 100-year design storm.
This alternative would provide the least direct impact to OSMP lands and environmental
resources from berm construction.
This CDOT ROW option calls for modifying the multi-use path that CDOT is currently
constructing within land it owns. CDOT has already mitigated for environmental impacts
for use of this land and therefore staff anticipates little or no mitigation for modification
of the path for the regional stormwater detention berm would be needed.
The multi-use path would need to be modified including constructing walls and raising
es
could fit within the existing CDOT ROW, but the design phases would need to confirm
this assumption and identify any possible temporary impacts that would need to be
mitigated during construction.
CDOT representatives have stated that should the ultimate US 36 configuration be
constructed, additional lanes could be built on the north side of the existing highway and
within their existing ROW. This would eliminate the need to remove and replace the
path a second time, and would leave the berm unaffected.
request to
consider developing an agreement to use a portion of the US 36 Phase 2 Bikeway located
within CDOT ROW to function as a berm provided that the mainline of US 36 and the
permanent water quality features remain intact. The estimated cost for this option is $22
million with a B/C ratio of 1.2.
CU has also indicated they are willing to engage in discussion to move forward with
implementation of Option D. If this recommendation is accepted by City Council, the
plans would be refined according to agreements reached with CDOT and CU. This
mitigation plan would then need to be reviewed through the Community Environmental
Assessment Process (CEAP) and the berm would need to be reviewed and approved by
the Office of the State Engineer.
However, the Boards could recommend and City Council could accept other options for
Table 2.0
South Boulder Creek flood mitigation. below presents a summary of the
anticipated next steps resulting from potential City Council decisions.
AGENDA ITEM #5 PAGE 8
Table 2.0: Summary of Approval Processes
Outcomes:
EnvironmentalCU CDOT Comp Plan # Structures in 100-Yr.
Council Decision
ProcessAgreementsAgreementsUpdates Floodplain within city
limits
Status Quo
None None None None 442
Phase II and III
Approved but US
None None None
CEAP 442
36 Detention not
Approved
Staff
Recommended
Yes Yes Yes
1/2
Option D with CEAPOSE 80
Phases II and III
Approved
Option C with
Yes No Yes
Phase II and III EA or EIS/OSE 80
Approved
Option A with
Yes No Yes
Phases II and III EIS/OSE 80
Approved
Any of Options
B, E, F, or G
Yes No Yes
EA or EIS/OSE 80
with Phase II and
III Approved
1. Assumes Option D can be constructed with no impacts to Threatened or Endangered Species or regulated
wetlands.
2. Office of State Engineer review and approval of the detention facility.
Any City Council acceptance of a capital improvement project will also require a design
phase and floodplain remapping submittals to FEMA, and may require wetland permits
and USFWS consultation.
The remaining options are not being recommended at this time as they all have similar or
greater berm and associated environmental impacts to OSMP lands. All other options,
except for Option A, have greater i property. Additionally, all of the dual
berm options carry a higher cost and a lower benefit to cost ratio than the single-berm
options.
NEXT STEPS:
The revised options and staff recommendation along with the WRAB and OSBT motions
will be presented to City Council on Aug. 4, 2015. Should City Council accept the
South Boulder Creek Flood Mitigation Plan with Option D as the concept for US 36
regional detention, city staff will initiate discussions with CU and CDOT in order to
further refine the plans. Consideration of changes to the land use designations on CU
Campus South as a component of the BVCP update will also factor into these discussions
with CU. A CEAP will also be initiated once plans reach the appropriate stage of
refinement.
ATTACHMENTS:
A. Study Area
B. US36 Regional Detention Options A-G
AGENDA ITEM #5 PAGE 9
CITY OF BOULDER
WATER RESOURCES ADVISORY BOARD
AGENDA ITEM
MEETING DATE: May 18, 2015
AGENDA TITLE:
Information Item - Draft Proposed 2016 Utilities Budget (Water,
Wastewater and Stormwater/ Flood Management) including the 6-year Capital Improvement
Program (CIP)
PRESENTERS:
Jeff Arthur, Director of Public Works for Utilities
Ken Baird, Utilities Financial Manager
Douglas Sullivan, Acting Principal Engineer Water, Wastewater, and Stormwater
Annie Noble, Acting Principal Engineer Flood and Greenways
Joe Taddeucci, Water Resources Manager
Bret Linenfelser, Water Quality & Environmental Services Manager
Russ Sands, Watershed Sustainability & Outreach Supervisor
EXECUTIVE SUMMARY:
a six-year planning budget, this
year for the time period of 2016 through 2021. The Water Resources Advisory Board (WRAB)
role in this process is defined in the
assessments and capital improvements conductUtilities
staff has formulated initial revenue and expenditure projections for each of the three utility funds
through the year 2021. Within the budget process, City Council approves and appropriates funds
only for the first year, 2016.
WRAB will be asked to make a recommendation to City Council regarding the 2016-2021 CIP at
its June meeting. The Planning Board will review the complete city CIP, including utilities, in
July. City Council will discuss the CIP in August at a study session, and the overall budget is
scheduled to be adopted by City Council in October.
This packet contains the draft proposed 2016 Utilities Budget and 2016-2021 Utilities CIP. The
Attachment A
fundfinancials ()have been updated to reflect actual revenues and expenditures
for 2014, and the revised budget for 2015. These fund financials incorporate recommended
changes to the CIP. There will be other likely less significant changes in the operating budget as
the guidelines recently provided by the budget office are incorporated into each fund. The draft
proposed CIP spreadsheets for Water, Wastewater and Stormwater/Flood Management are
Attachment B
included in .
Page 1
AGENDA ITEM #6
FISCAL IMPACTS:
Based on updates to the CIP and updated Fund Financials, staff is recommending rate increases
of 8% in the Water Fund, 5% in Wastewater, and 4% in Stormwater/Flood Management. These
were the anticipated increases for 2016 based on the six year CIP presented through the 2015
budget process.
PUBLIC FEEDBACK:
A public hearing and recommendation is scheduled for the June WRAB meeting. At the June
meeting, staff will request that the WRAB provide a final recommendation to City Council
regarding the proposed 2016-2021 CIP and associated rates changes.
BACKGROUND and ANALYSIS:
The preliminary draft 2016 budget provided with this memorandum reflects the following billed
revenue increases:8% Water, 5% Wastewater, and 4% Stormwater/Flood Management. The
following table summarizes the 2015 adopted increase and preliminary projections for 2016-
2018. The preliminary 2016 increases are in bold.
Table 1 Proposed Rate Increases
2015201620172018
Water5%8%8%8%
Wastewater30%5%5%5%
Stormwater/Flood Management75%4%8%8%
Utility Bill Comparisons
Attachment C
Colorado Front Range communities. shows the annual single-family residential
comparison for each of the three utilities. Since 2016 rate proposals are not yet available for the
other cities, therefore, the survey uses their 2015 rates. Based on rate projections previously
published by other utilities, on will be similar once all
2016rates are known.
Single Family Residential Customer Bill Impact
The proposed preliminary 2016 revenue increases (8%-5%-4%) would increase a typical
monthly utility bill by $4.98 or an increase of $59.76 annually. The
following table provides a breakdown of the potential increases by utility. Details about bill
impacts for commercials will be provided during the May 18 WRAB meeting.
Page 2
AGENDA ITEM #6
Table 2 Average Monthly Bill Impacts
Monthly Bill Monthly Bill Monthly
2015Rates2016RatesDifference
Water$36.59$39.48$2.89
Wastewater$30.23$31.78$1.55
Stormwater/ Flood Mgmt$13.46$14.00$0.54
Total$80.28$85.26$4.98
Impact of Rate Changes
The impact of a 1% increase in revenue varies substantially across the three funds:
Table 3 Rate Impact
1%2%3%
Water$235,000$470,000$705,000
Wastewater$185,000$370,000$555,000
Stormwater / Flood Mgmt$ 100,000$200,000$300,000
Also, as a point of reference, $100,000 provides for debt service coverage on a bond of
approximately $1,000,000. So a revenue reduction of $100,000 could mean reduced funding for
aone-time capital expense or capital bond project by $1,000,000.
Summary of Changes tothe CIP Since April 28:
Thecurrent draft proposed CIPs contain several changes from the version reviewed by WRAB at
the April 28 meeting:
Water Fund - $2,500,000 was removed in 2016 for the Annexation Related Water System
Expansion project.
annexing properties into the City, but this level of funding is not needed. Reducing this project
from the CIP will net to zero impact on the Water Fund Financial due to also eliminating the
corresponding anticipated revenue that would have been received from the residents annexing
into the City.
Wastewater Fund - $116,986 was added to the Wastewater Treatment Facility (WWTF)
Activated Sludge project in 2017. This will fund regularly scheduled maintenance to the three
blowers that supply the air requirements for the facilitActivated Sludge biological process.
Stormwater/Flood Management Fund - the funding of $2,250,000 for the Boulder Creek project
has been moved from 2016 to 2018. The change in the timing for this project will better coincide
with the Boulder Creek Mitigation Plan.
Page 3
AGENDA ITEM #6
BOARD FEEDBACK:
At the April 27, 2015 WRAB meeting, staff provided an overview of the 2016-2021 CIP with an
emphasis on key projects and asset management needs in each of the three funds. The WRAB
was generally supportive of the proposed projects in the CIP and discussion focused largely on
financial aspects. Additional information in response to WRAB feedback and discussion is
provided below and will be presented in greater detail at the May 18, 2015 meeting.
Ongoing Rate Increases
Board members raised concerns that the proposed 2016 increases and those anticipated in future
years were larger than what had been done historically. There was also concern about erosion of
public support and customer ability to pay with increases being requested every year. The history
Attachment D
of rate increases since 2003 is included in . In the years 2010 through 2012, the
increases were either 0% or 3%, but previous to that the rates were more varied, with the most
notable being two years of 20% increases in the Wastewater Utility in 2005 and 2006. These
larger rate increases corresponded to a Wastewater Treatment Facility project for which over $45
Million in bonds were issued. In the proposed 6-year CIP in the Water fund, there are nearly $72
Million in bonds anticipated to be issued for major projects. An alternative rate scenario in the
Water Fund to having 8% increases for the next three years is to have a larger increase in 2016,
followed by smaller inflationary increases in the subsequent years. For example, one option
would be a 12% increase in 2016, and then 4% for the following years. The current
and instead spread the impact to multiple years.
In considering the reasonableness of rate increases, a common comparison is the all items
Consumer Price Index (CPI), which measures the average change over time in prices paid for a
Attachment E
market of consumer goods and services. As shown in , the combined
Boulder water and wastewater charges have increased at a greater rate than overall CPI since
have increased at a lower rate between 2007 and 2014. With the larger rate increases in 2015,
d wastewater increases are now closer to the national water and sewer index.
This national trend of higher than CPI rate increases was also confirmed in a recently published
rate survey that can be accessed at this link.The same is true when comparing rate increases
Attachment F
with Front Range communities. shows Boulders charges for water, wastewater
and stormwater have lagged behind peer cities between 2007 and 2014, and the 2015 rate
increases bring the bills to slightly below average of the comparison communities. The years of
0% to 3% rate increases created a relative lag behind other Utilities, and resulted in less funding
available through those years.
It is also worth noting that several comparison cities have approved or are considering significant
future increases to address issues such as increased regulatory requirements, aging infrastructure,
and flood management. Indications are that the average rates charged in the past (both regionally
and nationally) are not sufficient to address current and future infrastructure needs. There is also
the question of whether maintaining below average rates is consistent with other city objectives.
Page 4
AGENDA ITEM #6
The city has developed and maintains a water system with complexity more comparable to much
larger cities, in part to ensure a high level of reliability into the future. The community places a
high value on environmental stewardship and regularly strives to exceed minimum regulatory
standards and industry norms. Finally, the city is widely recognized as having the highest flash
flood risk in the state. The city has been able to maintain what is in many cases above average
service with below average rates through a long history of innovation, strategic investments, and
proactive approaches.
Utility Rate Study
The Utilities Division is in the early stages of conducting a rate study. The scope of the analysis
will be determined after receiving feedback from the community, WRAB, and City Council. In
April, post cards were sent to all customers inviting them to attend one of three open houses and
to complete an online survey. . Approximately 10 members of the public attended each event.
As of May 4, 2015 there have been 101 responses to the survey, out of approximately 29,000
customer accounts. The survey will remain open until May 22, 2015. Feedback received from
these events and the survey will be brought to WRAB at the June 22 meeting. The rate study will
t process including possible rate structure
modifications that could be implemented for 2017.
Water Conservation Impact on Rates
Based on r
(city) Water Conservation Program (WCP) officially started in 1992. Program goals included
reducing total consumption, reducing peak usage, and helping to delay the need for capital
improvement project investments (like the upgrades in capacity at the 63rd Water Treatment
Plant which were, in part, achieved due to water conservation efforts).
Goals set in the 2000 Water Conservation Futures Study to reduce total water usage by 20% were
shown to have been achieved in the 2011 Water Utility Master Plan. However, this reduction is
not necessa
from the 2002-
fixtures/appliances have had significant impacts on reduced consumption levels across the Front
Range.
.9 Million
gallons which could equate to roughly $15,000 in lost revenue each year. If the total loss in
revenue was totaled for the 23 years the WCP has been in place and applied to a single year, the
cumulative impact might result in a one-time, 2% rate increase. Thus, in any given year, water
conservation savings likely have a negligible impact on rate increases. Rather, because water
conservation efforts reduce the need to purchase new supply, decrease system water loss and
minimize municipal water usage (which does not contribute to utility revenue), the water
conservation program may actually help keep rates lower.
Page 5
AGENDA ITEM #6
Today, the Water Conservation Program works to meet multiple goals across the city in addition
to core conservation efforts (e.g. supporting climate goals through the water-energy nexus; water
loss analysis; etc). In addition to the State Water Plan, there are also new state requirements for
2016) which captures city water conservation goals and efforts. Staff will be working to update
the Water Efficiency Plan in 2015-2016 and will coordinate with WRAB on setting any new
water conservation goals.
Northern Water Rates and Carter Lake Pipeline Annual Maintenance Costs
organization, and also had questions about annual operating costs associated with the Carter Lake
Pipeline. Concerning costs, Northern Water completed a Cost-of-Service Rate Studyin 2014. In
The result of the Study is that open Colorado Big Thompson (CBT) rates will increase from $28
per acre-foot to $56.20 per acre-foot from 2014 to 2018 for municipal and industrial customers.
By way of comparison based on very rough estimates, it costs the City of Boulder about $300 per
acre-foot to deliver source water to the treatment facilities. Northern is able to deliver water at a
lower cost due to economy of scale (more water and larger population served). As another point
of reference, Section 5 of the Northern study presents benchmark comparisons and concludes that
Northern Water employs fewer staff (FTEs), carries less debt, and has lower total expenses on
average than other similar water providers.
he rate study was approved by the Northern Water
Board of Directors. The Board, similar to City Council, establishes policy and strategic direction
for the district. Directors from the eight counties within Northern Water boundaries are appointed
to 4-year terms by District Court judges. Boulder County has three representatives on the
Northern Board. Any future policies or policy changes would need to be approved by the
Northern Board, which holds monthly meetings that are open to the public. Like City Council,
the Northern Board provides opportunity for public input on policy matters.
Once completed, the Carter Lake Pipeline will carry
Boulder Reservoir Water Treatment Facility. The pipeline will be operated and maintained by
Northern Water, and there will be an annual operating cost to each of the project participants,
including the City of Boulder. Staff will work with Northern Water to confirm operating costs
prior to the 2017 budget process. Staff will also work with Northern to establish plans for hydro
development associated with the project and whether hydro would be a City or Northern facility
(City hydro revenue would be obtained either way).
Master Plan Updates
The Stormwater Master Plan (SMP) was completed in 2007 and provided the City with the
necessary planning tools and capital improvement projects to address flood management and
water quality. T
conveyance system, consisting of storm drains 18-inch diameter and greater, as well as larger
ays.
Page 6
AGENDA ITEM #6
The September 2013 flood event resulted in localized flooding throughout the City, and
highlighted that much of the city was developed prior to the adoption of current stormwater
rrent standards including
many areas with no formal stormwater facilities currently in place. . As described in the 2007
SMP and Design and Construction Standards (DCS), the current level of service
specified for residential areas is the 2-year design storm. All other areas of local and collector
storm drain system are designed for a 5-year storm level of service. With this master plan
update, the City
drainage conveyance and stormwater regulatory compliance. A draft update to the SMP is
expected to be completed for WRAB review in the summer of 2015.
The Wastewater Collection System Master Plan (WWCSMP) was completed in 2009. The
master plan included the development of a new GIS based hydraulic model and a list of
collection system recommendations.
The September 2013 flood was an extreme event that overwhelmed the sanitary sewer system in
numerous locations through rainfall induced inflow and infiltration (I&I). Following the event,
the city undertook a city-wide flow monitoring study to assess the level of baseline I&I in the
collection system. The flow monitoring evaluation consisted of 58 flow meters installed in the
collection system to measure flows for a three month period from May to July 2014.
The objectives of the WWCSMP Update include the following:
1.Incorporate I&I Evaluation data and results
2.Incorporate new information regarding flow split manholes
3.Incorporate 2013 flooding system capacity observations
4.Refine level of service recommendations from the 2009 WWCSMP
A draft update to the WWCSMP is expected to be completed for WRAB review in the summer
of 2015.
BUDGET SCHEDULE:
The current schedule of major budget milestones is provided below. Elements involving the
WRAB are highlighted in bold italics.
Milestone Date
WRAB Draft CIP Review May 18, 2015
Proposed Budget Submittal to City Manager May 29, 2015
WRAB Recommendation on CIP/Budget June 22, 2015
Departmental Budget Review by City Manager May/June 2015
Planning Board Recommendation on CIP July 2014
City Council Study Session on CIP August 11, 2015
City Council Study Session on Budget September 8 and 22, 2015
City Council Consideration/Adoption of Budget October 6 and 20, 2015
Page 7
AGENDA ITEM #6
NEXT STEPS:
Staff will present additional information to the WRAB at the May 18 meeting and staff is seeking
feedback on the draft proposed CIP, updated financial information, and potential rate impacts.
This feedback will be considered in finalizing the proposed budget that will be presented at the
June 22, 2015 WRAB meeting. At that meeting, staff will request that WRAB provide a final
recommendation concerning the proposed 2016-2021 CIP to Planning Board and City Council.
Attachments:
A:
Fund FinancialsWater, Wastewater, Stormwater/Flood Management
B:
Draft Proposed 2016-2021 CIP, Water, Wastewater, Stormwater/Flood Management
C:
Colorado Utility Bill Comparisons Water, Wastewater and Stormwater/Flood Management
D:
City of Boulder Utility Rate Change History
E
: Consumer Price Index Comparison
F:
Residential Annual Bill Change Comparison Boulder and Front Range Average
Page 8
AGENDA ITEM #6
Attachment B - DRAFT WATER CIP
AHIJKLMNO
1 11-May-15CITY OF BOULDER
2 DRAFT 2016-2021 CAPITAL IMPROVEMENT PROGRAM
3 WATER UTILITY FUND
4
5
6 Assumed Inflation Rate20142015201620172018201920202021
7 PROJECT NAMEACTUALREVISEDPROJECTEDPROJECTEDPROJECTEDPROJECTEDPROJECTEDPROJECTED
8
9 Treated Water Pressure Reducing and Hydroelectric Facilities
10 Kohler Hydro/PRV Facility$0$50,000$0$0$0$0$0$0
11 Maxwell Hydro/PRV Facility$0$50,000$0$0$0$0$0$0
12 Orodell Hydro/PRV Facility$0$0$75,000$0$0$0$0$0
13 Sunshine Hydro/PRV Facility$0$0$0$271,875$0$0$0$0
14 Pearl Street Hydro/PRV Facility$0$0$0$0$24,333$243,331$0$0
15 Subtotal - Treated Water PRV and Hydro$0$100,000$75,000$271,875$24,333$243,331$0$0
16
17 Water Treatment Facilities
18 Betasso WTF$413,974$1,108,318$900,000$0$0$0$00
19 Betasso WTF - Bond Proceeds$0$0$24,000,000$0$0$0$0$0
20 Bond Issuance Costs$0$0$240,000$0$350,000$0$100,000$0
21 Boulder Reservoir WTF$203,296$7,100$164,000$0$0$0$2,000,000$0
22 Boulder Res WTF - Bond Proceeds$0$0$0$0$0$0$0$0
23 Subtotal - Water Treatment Facilities$617,270$1,115,418$25,304,000$0$350,000$0$2,100,000$0
24
25
Treated Water Pump Stations
26 Cherryvale Pump Station$0$0$0$0$0$0$0$0
27 Boulder Reservoir WTF High Service Pump Station$0$84,289$0$0$0$0$0$0
28 Iris Pump Stations$0$0$0$0$0$0$0$0
29 Subtotal - Treated Water Pump Stations$0$84,289$0$0$0$0$0$0
30
31 Treated Water Storage Tanks
32 Gunbarrel Storage Tank$644,449$39,746$0$0$0$0$0$0
33 Maxwell Storage Tank$0$0$0$0$0$0$0$0
34 Booten Storage Tank$0$0$0$0$0$0$0$0
35 Devil's Thumb Storage Tank$0$50,000$0$0$0$0$0$0
36 Kohler Storage Tank$64$103,487$799,875$0$0$0$0$0
37 Chautauqua Storage Tank$0$0$0$0$0$0$0$0
38 Betasso Storage Tank$0$0$0$292,465$0$0$0$0
39 Boulder Reservoir Storage Tank$0$0$0$0$0$0$0$0
40 Subtotal - Treated Water Storage Tanks$644,513$193,233$799,875$292,465$0$0$0$0
41
42 Treated Water Distribution System
43 Zone Isolation Valves$0$0$0$0$0$0$0$0
44 Cathodic Protection$0$0$0$0$0$0$0$0
45 Waterline Replacement$3,293,113$3,522,017$3,352,960$3,487,078($0)$3,771,624$3,922,489$4,079,389
46 Subtotal - Treated Water Distribution System$3,293,113$3,522,017$3,352,960$3,487,078($0)$3,771,624$3,922,489$4,079,389
47
48 Treated Water Transmission System
49 Sunshine Transmission Pipe$568,313$2,259,938$0$0$0$0$0$0
50 Boulder Canyon - Orodell to Fourmile Pipe$0$0$0$0$0$0$0$0
51 Mountain Transmission Pipes$0$0$0$0$0$0$0$0
52 Zone 1 Transmission Pipes$0$0$0$0$250,000$0$0$250,000
53 Zone 2 Transmission Pipes$0$0$0$250,000$0$0$250,000$0
54 Zone 3 Transmission Pipes$0$0$1,200,000$0$0$250,000$0$0
55 Subtotal - Treated Water Transmission System$568,313$2,259,938$1,200,000$250,000$250,000$250,000$250,000$250,000
56
57 Source Water Transmission System
58 Lakewood Pipeline$0$530,400$0$0$0$316,330$0$0
59 Silver Lake Pipeline $0$0$0$0$0$0$0$0
60 Source Water Transmission Pipe Inspections$0$73,653$0$0$0$0$0$0
61 Subtotal - Source Water Transmission System$0$604,053$0$0$0$316,330$0$0
62
63 Barker Water System
64 Barker Gravity Pipeline Repair$305,389$475,882$667,416$1,169,859$1,216,653$1,265,319$1,315,932$1,368,569
65 Barker-Kossler Penstock Repair$0$0$0$116,986$0$0$0$0
66 Barker Dam Outlet$00$100,000$175,000$0$835,551$0$0
67 Barker Dam Outlet - Bond Proceeds$0$0$0$0$0$0$8,355,509$0
68 Barker Dam and Reservoir$2,625$495,174$65,000$50,000$0$0$0$0
69 Barker Hydro System Integration$0$0$0$0$0$0$0$0
70 Barker Relicensing$25,377$0$0$0$0$0$0$0
71 Barker Instream Flow Release$0$6,052$0$0$0$0$0$0
72 Barker Residence$78,481$214,799$0$0$0$0$0
73 Betasso Penstock$0$0$0$0$0$0$0$0
74 Kossler Dam$56,204$135,738$75,000$0$0$0$0$0
75 Subtotal - Barker Water System$468,076$1,327,645$907,416$1,511,844$1,216,653$2,100,870$9,671,441$1,368,569
76
77
Raw Water Storage Reservoirs
78 Albion Dam$0$80,000$125,000$0$341,636$3,416,361$0$0
79 Silver Lake Dam$0$75,000$0$0$100,000$0$0$0
80 Island Lake Dam$0$0$0$0$50,000$0$0$0
81 Green Lake 1 Dam$0$0$0$0$0$0$0$0
82 Green Lake 2 Dam - Bond Proceeds$0$0$0$0$0$0$0$0
83 Green Lake 2 Dam $0$24,719$0$0$0$0$75,000$486,773
84 Green Lake 3 Dam$0$0$0$0$0$0$0$0
85 Goose Lake Dam$0$20,000$0$0$75,000$0$0$0
86 Boulder Reservoir$0$0$50,000$0$0$0$118,434$0
DRAFT WATER CIP
Attachment B - DRAFT WATER CIP
AHIJKLMNO
1 11-May-15CITY OF BOULDER
2 DRAFT 2016-2021 CAPITAL IMPROVEMENT PROGRAM
3 WATER UTILITY FUND
4
5
6 Assumed Inflation Rate20142015201620172018201920202021
7 PROJECT NAMEACTUALREVISEDPROJECTEDPROJECTEDPROJECTEDPROJECTEDPROJECTEDPROJECTED
8
87 Lakewood Dam$0$0$0$0$124,707$0$0$0
88 Skyscraper Dam$0$0$0$0$0$0$0$171,071
89 Wittemyer Ponds$0$0$0$0$0$100,000$492,685$4,926,849
90 Subtotal - Raw Water Storage Reservoirs$0$199,719$175,000$0$691,343$3,516,361$686,119$5,584,692
91
92
Other Raw Water Facilities
93 Farmer's Ditch$0$0$0$0$0$108,160$0$0
94 Anderson Ditch$0$0$0$0$0$0$0$0
95 Source Water Facilities Rehab Program$150,000$150,000$150,000$150,000$150,000$150,000
96 Watershed Improvements$78,886$146,357$80,000$0$0$0$100,000$0
97 Nederland WWTP$0$0$0$0$0$0$0$0
98 Instream Flow Structures and Gaging$0$48,428$0$0$0$0$0$0
99 Como Creek Diversion Structure $0$0$0$0$0$0$0$0
100 Lakewood Diversion Structure $0$0$0$0$0$0$0$0
101 Silver Lake Diversion Structure$0$0$0$0$0$0$0$0
102 NCWCD Conveyance - Boulder Feeder Canal$25$61,271$0$0$0$0$0$0
103 NCWCD Conveyance - Carter Lake Pipeline$250,000$500,000$850,000$2,036,322$0$0$0$0
104 NCWCD Conveyance/Waterline replacement - Bond Proceeds$0$0$0$0$37,565,263$0$0$0
105 Subtotal - Other Raw Water Facilities$328,910$756,056$1,080,000$2,186,322$37,715,263$258,160$250,000$150,000
106
107
Source Water Pressure Reducing, Pumping and Hydroelectric
108 Lakewood Hydroelectric/PRV$0$0$130,000$0$0$300,000$0$0
109 Silver Lake Hydroelectric/PRV$0$150,000$25,000$50,000$80,000$0$0$0
110 Boulder Reservoir Intake and Pumping$0$0$0$0$0$0$0$0
111 Betasso Hydroelectric / Pressure Reducing Facility$134,404$0$0$380,000$480,000$0$0$0
112 Barker Dam Hydroelectric$0$00$0$0$0$0$0
113 Barker Dam Hydro$0$0$0$0$0$0$0$0
114 Boulder Canyon Hydroelectric$100,755$33,641$0$0$0$0$0$0
115 Boulder Canyon Hydro - Grant$0$0$0$0$0$0$0$0
116 Boulder Canyon Hydro - Grant$0$0$0$0$0$0$0$0
117 Carter Lake Hydroelectric$0$0$0$0$50,000$250,000$0$0
118 Carter Lake Hydro$0$0$0$0$0$0$2,500,000$0
119 Source Water Pressure Reducing, Pumping and Hydroelectric Facility Rehabilitation$0$0$0$0$0$0$193,472$201,210
120 Subtotal - Source Water PRV, Pumping and Hydro$235,159$183,641$155,000$430,000$610,000$550,000$2,693,472$201,210
121
122
Water Distribution System Expansion
123 Annexation Related Water System Expansion$0$2,551,700$0$0$0$0$0$0
124 Subtotal - Water Distribution System Expansion$0$2,551,700$0$0$0$0$0$0
125
126
Water System Monitoring and Metering
127 Automated Meter Reading$0$0$0$0$0$0$0$684,285
128 Water System Security/Quality Improvements$13,996$150,000$150,000$150,000$150,000$90,000$0$0
129 Source Water Monitoring and Protection$0$100,000$100,000$100,000$100,000$100,000$0$0
130 Distribution System Water Quality$14,100$0$0$0$0$0$0$0
131 Data Communications System$0$0$0$0$0$0$0$0
132 September 2013 Flood Disaster Recovery$860,072$304,301$0$0$0$0$0$0
133 Yards Master Plan Implementation$13,553$86,321$0$0$0$0$0$0
134 Utility Billing Computer System$0$100,000$0$0$0$0$125,000$0
135 Subtotal - Water System Monitoring and Metering$901,722$740,622$250,000$250,000$250,000$190,000$125,000$684,285
136
137 TOTAL CAPITAL USES OF FUNDS$7,057,076$13,638,331$33,299,251$8,679,585$41,107,591$11,196,676$19,698,520$12,318,145
DRAFT WATER CIP
Attachment B - DRAFT WASTEWATER CIP
AHIJKLMNO
1
11-May-15CITY OF BOULDER
2
DRAFT 2016 - 2021 CAPITAL IMPROVEMENT PROGRAM
3
WASTEWATER UTILITY FUND
4
5
6 Assumed Inflation Rate20142015201620172018201920202021
7 PROJECT NAMEACTUALREVISEDPROJECTEDPROJECTEDPROJECTEDPROJECTEDPROJECTEDPROJECTED
8
9 Wastewater Treatment
10 WWTF Pumps$0$0$150,000$0$0$0$0$0
11 WWTF Permit Improvements$438,080$4,194,112$150,000$0$750,000$1,500,000$0$136,857
12 WWTF Nutrient Management Grant$144,485
13 WWTF Permit Improvements - Proj. Bond$0$0$0$0$0$0$18,500,000$0
14 WWTF Laboratory$25,163$0$50,000$0$0$0$0$0
15 Lower Boulder Creek Enhancement$0$0$0$0$0$0$0$0
16 WWTF Headworks$0$0$0$0$0$0$0$0
17 WWTF Headworks - Proj. Bond$0$0$0$0$0$0$0$0
18 WWTF Instrumentation/Control$0$1,127,477$0$674,918$701,915$729,992$759,191$0
19 WWTF Electrical$0$0$120,000$1,200,000$0$0$0$0
20 WWTF Activated Sludge$0$389,376$0$175,479$0$0$0$0
21 WWTF Primary Clarifiers$0$0$0$0$0$0$0$0
22 WWTF Secondary Clarifiers$0$0$0$0$0$0$0$0
23 WWTF UV Disinfection$2,356$2,998$0$0$0$0$0$0
24 WWTF UV Disinfection - Proj. Bond$0$0$0$0$0$0$0$0
25 WWTF Permit Improvements - 2010 Bond$15,148$1,198$0$0$0$0$0$0
26 WWTF Rehabilitation$0$0$0$0$0$0$150,000$375,000
27 Valmont Butte$0$0$0$0$0$0$0$0
28 Biosolids Processing & Dewatering$110,044$0$0$0$0$0$0$0
29 WWTF Biosolids Digester$20,000$0$0$0$0$0$0$0
30 WWTF Biosolids Digester - Proj. Bond$0$0$0$0$0$0$0$0
31 WWTF Cogeneration$0$39,995$0$0$0$0$184,481$0
32 WWTF Digester Complex$0$0$0$0$0$200,000$2,000,000$0
33 September 2013 Flood Disaster Recovery$453,442$606,987$0$0$0$0$0$0
34 WWTF Digester Cleaning$0$0$0$0$0$0$0$0
35 Bond Issuance Costs$0$125,000$0$0$0$0$125,000$0
36 Subtotal - Wastewater Treatment Plant$1,208,718$6,487,143$470,000$2,050,397$1,451,915$2,429,992$21,718,672$511,857
37
38 Marshall Landfill
39 Marshall Landfill$0$0$100,000$0$0$0$0$0
40 Subtotal - Marshall Landfill$0$0$100,000$0$0$0$0$0
41
42 Wastewater System Monitoring and Metering
43 Yards Master Plan Implementation$6,777$36,046$0$0$0$0$0$0
44 Automated Meter Reading$0$0$0$0$0$0$0$0
45 Utility Billing Computer System$0$50,000$0$0$0$0$65,000$0
46 Subtotal - Monitoring and Metering$6,777$86,046$0$0$0$0$65,000$0
47
48 Collection and Conveyance System Rehabilitation
49 Collection System Monitoring$338,636$3,426$0$0$0$0$0$0
50 Condition Assessment Program$780,000$811,200$843,648$877,394$912,490$948,989$986,949
51 Sanitary Sewer Rehabilitation$403,808$3,000,161$2,758,080$2,868,403$2,983,139$3,102,465$3,226,563$3,355,626
52 Sanitary Sewer Rehabilitation - Bond - 10,000,000 - - - - -
-
53 Sanitary Sewer Manhole Rehabilitation$51,186$208,000$216,320$224,973$233,972$243,331$253,064$657,966
54 IBM Pump Station$79,395$1,235,402$0$0$0$0$0$0
55 Tier 1 Boulder Creek 2 Master Plan Project$0$0$0$0$0$0$0$0
56 Tier 1 Goose Creek 1/1A Master Plan Project$0$0$0$0$0$0$0$329,278
57 Tier 1 Goose Creek 3 Master Plan Project$0$0$0$0$0$0$0$0
58 Tier 1 Goose Creek 5 Master Plan Project$0$0$0$0$25,000$647,590$1,346,988$1,400,867
59 Tier 2 Boulder Creek 1 Master Plan Project$0$0$0$0$0$0$0$0
60 Tier 2 Boulder Creek 3 Master Plan Project$0$0$0$0$0$0$0$0
61 Tier 2 Boulder Creek 4 Master Plan Project$0$0$0$0$0$0$0$0
62 Tier 2 Goose Creek 4 Master Plan Project$0$0$0$0$0$0$0$0
63 Tier 2 Gunbarrel 1 Master Plan Project$0$0$0$0$0$0$0$0
64 Tier 2 Gunbarrel 2 Master Plan Project$0$0$0$0$0$0$0$0
65 Tier 2 South Boulder Creek 1 Master Plan Project$0$0$0$0$0$0$0$0
66 Subtotal - Sewer System Rehabilitation$873,024$15,226,990$3,785,600$3,937,024$4,119,505$4,905,875$5,775,604$6,730,686
67
68 Wastewater System Expansion
69 Annexation Related WW System Expansion$0$0$0$0$0$0$0$0
70 Subtotal - Wastewater System Expansion$0$0$0$0$0$0$0$0
71
72 TOTAL CAPITAL USES OF FUNDS$2,088,519$21,800,178$4,355,600$5,987,421$5,571,420$7,335,867$27,559,277$7,242,543
DRAFT WASTEWATER CIP
CITY OF BOULDER
Attachment D
UTILITIES REVENUE INCREASES
YearFundIncrease
2003
Water3.0%
Wastewater12.0%
Storm/Flood6.0%
2004
Water0.0%
Wastewater6.0%
Storm/Flood3.0%
2005
Water3.0%
Wastewater20.0%
Storm/Flood3.0%
2006
Water3.0%
Wastewater20.0%
Storm/Flood3.0%
2007
Water4.0%
Wastewater6.0%
Storm/Flood3.0%
2008
Water4.0%
Wastewater3.0%
Storm/Flood3.0%
2009
Water8.0%
Wastewater5.0%
Storm/Flood3.0%
2010
Water0.0%
Wastewater0.0%
Storm/Flood0.0%
2011
Water3.0%
Wastewater3.0%
Storm/Flood0.0%
2012
Water3.0%
Wastewater3.0%
Storm/Flood3.0%
2013
Water3.0%
Wastewater5.0%
Storm/Flood3.0%
2014
Water4.0%
Wastewater5.0%
Storm/Flood3.0%
2015
Water5.0%
Wastewater30.0%
Storm/Flood75.0%
2016
Water8.0%
proposed
Wastewater5.0%
Storm/Flood4.0%
0% WW
Board and Commission - Civic Area Information Item
C I T Y OF B O U L D E R
BOARD & COMMISSION INFORMATION ITEM
TO:
Boulder Arts Commission
Boulder Design Advisory Board
Downtown Management Commission
Greenways Advisory Committee
Human Relations Commission
Landmarks Board
Library Commission
Parks and Recreation Advisory Board
Transportation Advisory Board
Water Resources Advisory Board
FROM:
David Driskell, Executive Director of Community Planning & Sustainability
Maureen Rait, Executive Director of Public Works
Yvette Bowden, Director of Parks and Recreation
Sam Assefa, Senior Urban Designer, Project Coordinator
Jeff Haley, Project Coordinator
Joanna Crean, Project Coordinator
DATE:
May 8, 2015
SUBJECT:
Update on the Boulder Civic Area Master Plan and Park Site Plan
EXECUTIVE SUMMARY:
With the passage of the Community, Culture and Safety tax initiative in November 2014, the
first phase of improvements in the Civic Area continue to move forward. Building on the
council-adopted vision planand community feedback, a Civic Area Park Site Plan is being
developed to implement the $8.7 million Phase I improvements and coordinate with the more
th
than $5 million from the tax devoted to Boulder Creek Path, 11Street lighting, public art and
Arapahoe underpass improvements. Additionally, in order to advance implementation items for
the near-term and guide further work on longer-term investments, amendments to the adopted
Civic Area Vision Plan have been developed with the intent of replacing the existing 1992
Boulder Civic Center Master Plan and serving as the updated Civic Area Master Plan.
The purpose of this information item is to provide an update on the Civic Area project,
including:
Attachment A
Civic Area Master Plan (),
Attachment B
Park Site Plan (), and
Project schedule for 2015.
1 of 29
Board and Commission - Civic Area Information Item
BACKGROUND
In January, 1993, the City Council adopted the 1992 Civic Center Master Plan, which served as
an implementation tool to translate the Boulder Valley Comprehensive Plan (BVCP) into action.
While the 1992 Civic Area Master Plan guided some implementation efforts subsequent to its
adoption, many of its proposals were never realized.
On Sept. 3, 2013 City Council approved the Vision Plan for Boulder’s Civic Area thatreflects
18-month collaboration with the Boulder community, boards and commissions and City Council.
The long-term vision is to transform the Civic Area into an evenmore unique place that reflects
the community’s shared values and its diversity, providing space and programs for people to
gather, recreate, eat, learn, deliberate and innovate. The vision plan established site performance
goals, guiding principles and core themes for the Civic Area.
However, the vision plan was not adopted as amaster plan, a necessary implementation
document that provides a common framework for planning the delivery and funding of city
services, facilities and programs.Therefore,amending the vision plan and presenting it for
adoption as the updated Civic Area Master Plan is needed.The updated plan will integrate
technical and site analysis and public input, including amendments to enhance the goals, guiding
principles and core themes.
With the passage of the Community, Culture and Safety tax initiative in November 2014, a Civic
Area Park Site Plan is being developed to implement the $8.7 million in phase I improvements
th
and coordinate with the more than $5 million from the tax devoted to Boulder Creek Path, 11
Street lighting and Arapahoe underpass improvements. In order to advance these Phase I
improvements and guide further work on longer-term investments, updating the Civic Area
Master Planis necessary.
PUBLIC AND BOARD/COMMISSION COMMENT AND PROCESS
:
In the fall of 2014, community feedback was collected about program preferences and park
1
design themes. In March 2015, the city hosted a stakeholder workshop and a public open house
as well as a joint board and commission workshop. The purpose was to collect feedback on draft
Park Site Plan options and long-term improvement strategies related to the Master Plan update.
Below is a brief summary of the consistent themes. Follow the link
https://bouldercolorado.gov/planning/boulder-civic-area-projectfor a more detailed summary of
the comments as well as the verbatim commentsfrom each meeting.
Park Development
Participants expressed overall support for the plans and believe that the designs will begin to
transform the area into a more actively used and engaging public space. Many agree the physical
site development must be complemented by intentional programs and activation strategies to
invite users with a range of dynamic activities supported by attractive public spaces. Community
members offered that certain existing uses should be reconsidered and improved such as the
1
Stakeholders, for the purpose of this workshop, includedon-site property owners and tenants,organizations
with a clearinterest in the project, and participants from previous Civic Area focus groups.
2 of 29
Board and Commission - Civic Area Information Item
current alignment of the Boulder Creek Path and the location of the bandshell to achieve desired
outcomes. Additionally, strong emphasis was placed on the Farmers’ Market and opportunities
for expansion into the park.
East Bookend
The general preferenceis for a mix of uses in the 1300 Block, not for single predominant use
such as a large municipal facility orperforming arts center. However, manyexpressed desirefor
small performance or events spacethat will activate the area. Additionally, smaller scale building
forms are preferred to allow more permeability, sightlines and to bring light and air to the plazas
and the outdoor Farmers’ Market. Finally, there are mixed views related to the existing Atrium
building. Some felt it could be repurposed, while others felt it would be better to redevelop the
site to accommodate a richer mix of uses.
West Bookend
Outreach indicated that the west end needs more activation and mix of uses ranging from senior
services to performance spaces and enhanced connection to park areas. While there is mixed
support for new residential use, there is consistent support for parking structures to be located in
this area to support the larger development of the Civic Area. Some expressed interest in
expanding the Canyon theatre to increase performance space as small size venuesto complement
the existinglibrary function.
On March 31, 2015, this information was presented to City Council during a Study Session.
After receiving City Council feedback on strategies for the long-term improvements, the Civic
Area Master Plan and Park Site Plan wererevised accordingly.
CIVIC AREA MASTER PLAN
The Boulder Civic Area Master Plan outlines a roadmap for the future enhancement and
transformation of the Boulder’s “Civic Heart” into a place for community inclusiveness and
activity—a cohesive and expanded central “green” at the core, bookended by vibrant “built”
mixed-use blocks on the west and east ends. Boulder Creek serves as the defining feature that
establishes much of the natural beauty of the Civic Area and captures the beauty of Downtown
Boulder. The roadmap is articulated in the key section of the plan, which includes the Guiding
Principles, illustrative plans, phasing, park and “bookend” development criteria, land use
priorities, and financing strategies and options, all of which were developed consistent with the
Attachment A
BVCP(see for details).
One of the specific uses identified in the Civic Area Master Plan is a year-round Market Hall that
complementsthe existing Farmers’ Market as well as advance local foods and activate the East
End. The project team will initiate a feasibility analysis to identify the type and scale of a year-
round market hall appropriate for Boulder and the Civic Area, including associated
programming, governance, financing and infrastructure. Concurrently, the city-owned Atrium
Building that is located within the east bookend has been suggested as a potential location for the
year-round Market Hall. The Feasibility Analysis will include an architectural and program
analysis that will explore this option either within the Atrium Building, or as part of a new
mixed-use building. Additionally, Historic Boulder has recently submitted an application to the
city for the landmarking of the Atrium Building.
3 of 29
Board and Commission - Civic Area Information Item
PARK SITE PLAN
The initial park design process included three plan alternatives that illustrated multiple scenarios
for improvements to achieve the park development goals. Based on the feedback received and
guidance from the vision plan, a preferred option has been developed that incorporates the
successful elements of each of the alternatives. The preferred hybrid-plan combines all the
th
elements such as a promenade along Canyon, 11Street “spine,” creek terraces, nature play,
improved creek path, plaza spaces and an expanded Farmers’ Market area. The plan can be
(Attachment B)
viewed in and will continue to be refined through an ongoing design process
described below in “Next Steps”
Throughout this spring and summer, the Park Site Plan will also be informed by detailed site
analysis work and various concurrent technical studies, including the Canyon Boulevard
Complete Street that began in 2014 and will continue through 2015. Several allied initiatives will
also ensure the Civic Area continues its transformation through the following opportunities:
Nature Play –
On June 10 and 11, 2015 the city will host aNature Play Symposium and
Workshop with Robin Moore and Louise Chawla. Robin is a world-renowned nature play
educator from North Carolina State University. Louise is a professor emeritus at CU
Boulder’s Environmental Design School, an internationally recognized expert on the
importance of nature in child development, and lead advisor with Growing Up Boulder
(GUB). Robin and Louise will share their expertise on the importance of nature play
opportunities in the urban setting and provide design examples from other communities.
This interactive workshop will inform the nature play design development, integrating
nature play and learning with the new children’s library wing and other parts of the park
design.
Activation & Programming –
Several events and initiatives are scheduled for the
upcoming spring and summer to continue activation of the Civic Area. A current listing
of activities will continue to be updated on the Civic Area website throughout the
summer.
NEXT STEPS: PROJECT SCHEDULE FOR 2015
The Civic Area Master Plan will be presented to Planning Board on May 21 and will then be
presented to City Council as a public hearing item for review and consideration on June 16,
2015. Concurrently, staff continues to develop the Park Site Plan that refines the design
considerations set forth in the Civic Area Master Plan in order to begin implementation of Phase
I construction in 2016. During the fourth quarter of 2015, the Park Site Plan will be brought to
the Parks and Recreation Advisory Board (PRAB), Planning Board and City Council for review
and consideration.
The public will also have the opportunity to provide input on key design elements identified in
the Park Site Plan through upcoming outreach. The project team has identified a Design
Inspiration Initiative that will solicit ideas from the community to inspire the final design of a
few key elements of the plan. Details of this initiative will be communicated in the coming
weeks. Additional key dates for the project include:
4 of 29
Board and Commission - Civic Area Information Item
Mid July 2015 – Community Open House to review outcomes of the Design Inspiration
Initiative and latest Park Site Plan
July 28, 2015 – City Council briefing on outcomes of Design Inspiration Initiative and
Park Site Plan
In addition to the updated Civic Area Master Plan and the Park Site Plan, the city will be
developing guidelines for future improvements for the west and east “bookends” of the Civic
Area. The primary goal is to serve as an implementation tool to provide clear design guidelines
on urban form that address scale, mass, height and architectural character of buildings and set
standards for the public realm including connections and public spaces such as plazas. This work
will be developed later in 2015 and early 2016 through a robust public process, including the
engagements of boards, commissions and council, and will be presented for council’s acceptance
in 2016. The Civic Area design guidelines for the bookends will be informed by the update to the
Downtown Design Guidelines and the Form Based Code pilot, both of which are scheduled to be
completed later this year.
ATTACHMENTS:
A
– Draft Civic Area Master Plan
B
–Park Site Plan
5 of 29
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6 of 29
Boulder Creek Watershed Master Plan Information Item
Draft
Boulder Creek Watershed Master Plan Information Item
C I T Y O F B O U L D E R
INFORMATION ITEM FOR:
ENVIRONMENTAL ADVISORY BOARD – May 6, 2015
PLANNING BOARD – May 21, 2015
TRANSPORTATION ADVISORY BOARD – May 11, 2015
OPEN SPACE BOARD OF TRUSTEES – May 13, 2015
WATER RESOURCES ADVISORY BOARD – May 18, 2015
PARKS AND RECREATION ADVISORY BOARD –May 18, 2015
GREENWAYS ADVISORY COMMITTEE AGENDA ITEM
MEETING DATE:May 26, 2015
SUBJECT:
2016-2021 Greenways Capital Improvement Program
REQUESTING DEPARTMENT:
Annie Noble – Flood and Greenways Engineering Coordinator
PURPOSE:
The 2016-2021 Greenways Capital Improvement Program is being provided to
board members as an information item. If you have any comments or concerns regarding the
2016-2021 Greenways Capital Improvement Program, please pass them along to your
Greenways Advisory Committee representative. If you have questions on this material, please
contact Annie Noble at 303-441-3242 or noblea@bouldercolorado.gov
GREENWAYS ADVISORY COMMITTEEACTION REQUESTED:
A recommendation from the Greenways Advisory Committee to the City’s Planning Board
and City Council concerning the proposed Greenways Capital Improvement Program is
requested.
Attached is information concerning the proposed 2016-2021 Greenways Capital Improvement
Program (CIP) for review and consideration. A recommendation by the Greenways Advisory
Committee to the city’s Planning Board and Council will be requestedat the May 26, 2015 GAC
meeting.
Attachment A: Greenways 2016-2021 Capital Improvement Program Overview
Attachment B: Greenways 2016-2021 Capital Improvement Program Summary Spreadsheet
Attachment C: Greenways Program CIP Map
2016-2021 Greenways Capital Improvement Program Information Item1 of 8
Greenways
Program Overview
The City of Boulder Greenways System is comprised of a series of corridors along riparian areas
including Boulder Creek and its 14 tributaries, which provide an opportunity to integrate
multiple objectives, including habitat protection, water quality enhancement, storm drainage
and floodplain management, alternative transportation routes for pedestrians and bicyclists,
recreation and cultural resources.
The Greenways CIP follows an opportunistic approach, contributing funding toward projects
that are being completed by other departments or private development in order to meet the
various objectives of the Greenways Program. The Greenways CIP also looks to leverage funds
with outside agencies in order to move projects forward that meet more than one objective of
the Greenways Program, but may not be the highest priority when evaluating any one particular
objective. Projects included in the Greenways CIP are typically called out in the Greenways
Master Plan and are projects that Greenways staff can take the lead in coordinating.
Funding Overview
The total 2016 Greenways capital budget is $320,441, with $105,000 in the operating budget.
Greenways projects are funded from the Transportation Fund, Stormwater and Flood
Management Utility Fund, and the Lottery Fund. Annual funding distribution for the Greenways
Capital Program for 2016 is as follows:
Transportation - $97,500
Flood Utility - $97,500
Lottery Fund - $125,441
Historically the Lottery contribution to the Greenways Program has been $150,000 per year. As
a result of a projected reduction of the city’s allocation of Lottery funds, starting in 2015, the
Lottery contribution to Greenways is expected to be reduced to $125,441 (based on Greenways
receiving 15% of the city’s funding allocation, with a projection of total Lottery proceeds being
$836,275). Should the city’s allocation of Lottery funds exceed the projected amount, a budget
adjustment will be made to reflect the increase.
2016-2021 Greenways Capital Improvement Program Information Item2 of 8
Accomplishments and Highlights
Projects to be Completed in 2015:
The Goose Creek Restoration Project includes restoration improvements along Goose
Creek between Foothills Highway and 55Street. This project was completed in 2014.
th
However, it was determined that reinforcement of the multi-use path was necessary
after several small storm events last summer. This work will be completed this summer.
This project is primarily being funded through a Section 206 Restoration grant through
the U.S. Army Corps of Engineers. The city’s 35% funding match is being met mostly
through credits from city owned real estate.
Flood mapping studies are expected to be completed in 2015 and submitted to FEMA
for Boulder Slough, and Upper Goose and Twomile Canyon Creeks and Skunk, Kings
Gulch and Bluebell Canyon Creeks.
Flood mitigation major drainageway plans are anticipated to be completed by the end of
2015 for South Boulder Creek and Gregory Canyon Creek.
Construction of the Wonderland Creek Foothills to Winding Trail Greenways
Improvement Project is anticipated to begin in 2015 and is scheduled to be completed
in 2017.
The Urban Drainage and Flood Control District (UDFCD) also completes maintenance
projects along the major drainageways. In 2015 this includes a request for sediment
removal along Wonderland Creek from Foothills Parkway to the confluence with Goose
Creek. Selective thinning of non-native vegetation is also planned and coordinated
through the UDFCD for Bear Canyon Creek. These maintenance projects will help
maintain conveyance capacity in these drainageways.
Projects Expected for Completion in 2016:
A CEAP for the Fourmile Canyon Creek stream reach upstream of Upland Avenue to west
of Broadway is expected to be completed in 2016.
Flood mitigation plans are anticipated to be completed in 2016 for Boulder Creek and
Bear Canyon Creek.
Stream bank restoration work, which is being funded by the Community Culture and
Safety projects November 2014 tax increase is anticipated to be completed in 2016.
Projects Started in 2016, but Not Completed:
Fourmile Canyon Creek at 19 Street is in preliminary design but was put on hold
th
following the September 2013 flood event. It is anticipated that the design of this
2016-2021 Greenways Capital Improvement Program Information Item3 of 8
project will be completed in 2015 and the project will be bid in 2016 and completed in
2017.
Highlights of 2016 – 2021 Projects:
The focus of the 2016-2021 Greenways CIP is on flood mitigation, bicycle and pedestrian
multi-use paths and underpasses, and habitat and water quality improvements along the
Fourmile and Wonderland Creek corridors. In addition to the projects along Fourmile Canyon
Creek and Wonderland Creek, possible habitat restoration projects during the next few years
include:
Confluence of Bear Creek and Boulder Creek at Foothills Community Hospital
Dry Creek habitat improvements through Flatirons Golf Course
Goose Creek, railroad to 47 Street tree plantings
th
Fish Passage enhancement projects in association with Fishing is Fun grants
South Boulder Creek minimum stream flow
Removal of Russian Olive trees east of 75 Street along Boulder Creek
th
Relationship to Guiding Principles
CIP Guiding Principles:
Greenways projects address many of the CIP guiding principles. Greenways projects are
identified in multiple master plans and meet the community sustainability goals. Most of the
Greenways projects leverage outside or interdepartmental funding. Greenways habitat
improvements seek to be sustainable and are intended to reduce the future maintenance
required.
The Greenways CIP has been developed within the context of and is consistent with the Boulder
Valley Comprehensive Plan (BVCP), the Transportation Master Plan (TMP), the major drainageway
flood mitigation plans, the Comprehensive Flood and Stormwater Master Plan and the
Greenways Master Plan. The Greenways Master Plan was updated in 2011 to reflect
improvements that had been completed, and adopted changes that have been made in other
master plans, city policies and ordinances that affect the Greenways Program since the last
Master Plan update in 2001.
Prioritization:
Many of the Greenways projects shown in the CIP are being designed and constructed in
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coordination with major flood or transportation improvements. The Greenways funding
associated with these projects focuses on habitat restoration, water quality improvements and
trail connections. In addition to leveraging funding with the Transportation and Flood Utilities
budgets, funding for Greenways projects is also available through the Urban Drainage and
Flood Control District and Federal Transportation funds.
Projects not in Master Plans:
It should be noted that the city experienced a major flood in September 2013 that resulted in
extensive flooding along most of the city’s major drainageways. Following the flood, additional
funds have been allocated in the Flood Utility CIP to reflect an increased interest in pursuing
flood mitigation efforts along the city’s major drainageways. As a result of updated mapping
and the September 2013 flood, flood mitigation plans were initiated for Gregory Creek, Bear
Canyon Creek and Boulder Creek to identify economically feasible improvement projects. Flood
mitigation plans will be initiated in 2016 for Upper Goose Creek and Twomile Canyon Creek,
and Skunk, King’s Gulch and Bluebell Creeks after completion of flood mapping updates on
these drainageways. Results from these flood mitigation plans will inform future capital
improvements. Continued evaluation of potential improvement may result in additional
changes to the Flood Utility and Greenways CIP in upcoming years.
New Projects
The 2016-2021 CIP continues to focus on Fourmile Canyon and Wonderland Creeks. As stated
above, flood mitigation plans are currently being developed for several of the drainageways as a
result of either flood mapping updates or deficiencies identified during the September 2013
flood. These plans will identify potential economically feasible CIP projects which may provide
opportunities for future Greenways improvements.
Operation and Maintenance Impacts
$105,000 is budgeted each year for Greenways operations and maintenance. $80,000 of the
operating budget is dedicated to habitat maintenance. The Greenways habitat crew works
closely with Parks and Open Space maintenance staff to provide on-going maintenance, as well
as on collaborative projects as part of the operations budget. Major drainageway improvements
are maintained by the flood maintenance staff and multi-use paths and underpasses are
maintained by either Transportation or Parks maintenance, depending upon jurisdiction.
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Deferred, Eliminated, or Changed Projects
None
Unfunded Projects and Emerging Needs
Since the Greenways Program is opportunistic, taking advantage of projects that are funded
through other departments, there are no unfunded needs.
Board Action
The Greenways Advisory Committee will meet on May 26, 2015 to make a recommendation on
the 2016-2021 Greenways Program CIP to Planning Board and City Council.
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