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HomeMy WebLinkAbout8 - Update on current floodplain regulations and floodplain management work efforts including potential changes to the floodplain ...gulatory standards for critical facilitiesCITYOF BOLILDER ~V aTER RESOURt~ES ADV ISORY BOARD AGENDA ITEi~I 1~1EETING DATE: Febi•uary 25, 2008 AGENDA TITLE: Llpdate on current floodplain regulations and floodplain rnanagernent work efforts includinb potential changes to the floodplain rebulations that would require higher regulatory standards for critical facilities. PRESENTERS: Ned Williams, Director of Public Works for Utilities Bob Harberg, Utilities Planning and Project lVlanagement Coordinator ~nnie Noble, Greenways Coordinator Eric Lessard, Engineering Project I~Ianagei- Cristina h~Iartinez, Civil Engineer II ~~VATER RESOURCES ADVISQRY BO:~RD ACTION REQUESTED: The purpose of this agenda item is to update WRr1B on current floodplain regulations and floodplain management work efforts. In pa1-ticular, staff is interested in ~~~RAB's perspectit~e on the issue of changes to floodplain regulations that would require higher regulatoiy standards for critical facilities. FISCAL IMP~CT: None I. PURPOSE The purpose of this agenda item is to update t~'RAB on current floodplain regulations and floodplain management «7ork effoi-ts. In particular, staff is interested in ~URi~B's perspective on the issue of changes to floodplain regulations that would require higher regulatory standards for critical facilities. The city is trying to schedule a Floodplain and Wetland 11~Ianagement City Council Study Session to introduce Council to the puipose and importance of protecting floodplains and wetlands, to provide Council ~~ith background on current Floodplain and ~~Vetland Nlanagement Programs, and to get feedback frorn Council on floodplain and wetland policy issues and preliminary approaches for changing the Floodplain and Z~'etland ~rdinances. Planning and Development Seivices staff is prep~u•ing the ~~vetland component of the study session, ~~hile Public ~uorks Utilities Staff is preparing the floodplain management component. For the putpose of the Febt-uary 25~' meeting with the Water Resources ~dvisory Board {WR_~B), staff will focus on floodplain management and solicit input and comments from the WRAB on the preliminary draft outline Page 1 (Attachment A) for the study session packet/memorandum. Staff desires a discussion of ideas and issues about current floodplain policies and regulations, and what changes, specifically related to critical facilities, should be considered for the future. II. QUESTIONS FOR WRAB 1. Do WRAB members have questions about current floodplain regulations and floodplain management work efforts? 2. Does WRAB agree with previous Council direction for statTto evaluate changes to floodplain regulations that will require higher regulatory standards for critical facilities? 3. Does WRAB agree with the basic definition of critical structures? 4. Does Council have any questions or suggestions regarding the proposed technical analysis and public process prior to bringing forward a new ordinance regarding flood regulation standards for critical facilities? III. BACKGROUND A. Comprehensive Flood and Storm~~ater Master Plan The Comprehensive Drainage Utility Master Plan (CDUMP) was accepted in January 1989 as part of an identified need to update local floodplain management efforts. CDUMP defined a scope, funding and timing for CIP flood mitigation projects, high hazard structures acquisition, and a new stormwater quality program. CDUMP was also developed concurrently with the Tributary Greenways Master Plan in an effort to integrate program activities. The Comprehensive Flood and Stormwater (CFS) Master Plan was accepted in 2444 to update and replace the 1989 CDUMP. The CFS provides the current framework for addressing flood management program activities. A copy of the CFS Executive Summary is presented as Attachment A. B. Boulder's Floodplains Boulder is located at the base of the foothills where there is high potential for flash flood events which allow little time for warning. A major flood event, particularly on Boulder Creek, ~~-~ould result in substantial property damage and could result in loss of life. Because the threat to life and property damage is so great, the need to monitor and regulate the floodplain is critical. Boulder is impacted by 15 major drainageways or creeks, which pass through the city limits and include the follot~~ing designated water courses (Figure 1): • Bear Canyon Creek • Fourmile Canyon Creek • South Boulder Creek • Bluebell Canyon Creek • Goose Creek • Sunshine Creek • Boulder Creek • Gregory Canyon Creek • Twomile Canyon Creek • Elmer's Twomile Creek • Skunk Canyon Creek • Wonderland Creek • King's Gulch • Viele Channel Page 2 O Boultle~Reservol~ ~ a~or Drair~a~~~ ~ . ~s in Boulder=- s ~"ni/o ~ ~ o ~a. ~ ~ Wontle~lantl Lake Jay Rtl pie,.- P T l~ h Fig a 1 0 d a ~ ens 0 ~ rl A~a p~oe~ ° ~ a~n a 3 B I AYe - m I~e °~N ~t . Su se Crpek n s Gob _ , J~mO h/oe ~r _ r ~ c p ~ ~ ~ . c h h~ c von Ima o¢ m y. - - oulder ree P °yB e s~~ ~t T i ~ I ~ B 4ps ~ ~ ~ o IIb N (p. U~ ~ A pge s'~a ' Bluebell Greek. ee~°m°_ a O ~ ~ ~g _ Grp' ~y Gulch cGRa ~ s ~~m~R c~ ~ P t~ ableM G a~ a ' oc c r ~'`~oy ~o a i eatG o e' o i N 0 0 ~ viaia~ a; a 0 ~ 0 5, . ~ ~.o Figure 1-Major Drainageways in Boulder All the major drainageways passing through Boulder are ultimately tributary to Boulder Creek at the eastern city limits. The 100-year floodplains associated with these drainageways cover approximately 15 percent of the lands in the city (more than twice the national average of 7 percent), and this includes approximately 4,100 structures (last reported to be 3,515 single-family to four-family residential structures and 646 other structures). Flooding from these various creeks may be narrow and swift as with Boulder Creek downtown and Bear Canyon Creek in Table Mesa, or quite wide and highly dispersed, as recently identified for Fourmile Canyon Creek in North Boulder and South Boulder Creek in the Keewaydin Meadows area. Page 3 Structures in the 100 Year and 500 Year Floodplains zooo 1800 ~ 1600 1400 ' ~ 1200 ~ ~'i 1000 ~ y 800 ~ 600 / ~ 400 - 200 T o ~ U U U m U c o 0 0 ~ ~ ~ ~ ~ U ~ w ~ m ~ C7 0 ~ Y v ~ a m d N F V N p y l6 ii ~ o ro ~ a m W m o N c (9 N ~ ¦ 700 yr Structures ¦500 yr Structures Figure 2 -Properties with Structures ui Floodplant Areas (Note: iliele Channel is not shown and there are no known structures within the 1 f~f1 year or 5~~- year floodplains) It should be noted that floodplains are delineated only for major drainageways. C7ther areas of the city may still be subject to flooding due to more localized storm events. The city's Stormwater Master Plan focuses on identifying and addressing these types of hazards. C. Flood History The largest recorded flood in Boulder occurred over afour-day period along Boulder Creek from May 29 to June 1, 1894. The estimated 100-year flood coursed through the city, washing out the railroad, roads and numerous structures. In July 1909, flooding along Twomile Canyon Creek claimed two lives and hospitalized two more. An estimated 40-year flood struck Boulder Creek again in 1914, with subsequent flooding in 1919 and in 1921. Twomile Canyon Creek flooded again in September 1933, demonstrating that floods can occur in late fall. The largest flood of record for South Boulder Creek passed through Eldorado Springs and Marshall in 1938. The Eldorado Springs Resort was significantly damaged, including washing Page 4 away the dance hall and a number of cabins. Boulder Creek also flooded at this time. In May 1969, an estimated 25-year flood damaged significant areas along Boulder Creek, Bear Canyon Creek and South Boulder Creek. Boulder has been spared the impact of devastating floods over the last 38 years. However, several events estimated to be smaller than 20-year floods have occurred on the tributaries to Boulder Creek. Bear Canyon Creek, Fourmile Canyon Creek, Goose Creek, Gregory Creek and Twomile Canyon Creek have all experienced over bank flooding. Also in this region, floods that far exceeded the 104-year storm level occurred in the Big Thompson Canyon in 1976 and in Fort Collins in 1997. Flooding in the Big Thompson caused more than 140 fatalities. The Fort Collins flood caused the loss of five lives in an area that was considered to be outside of the floodplain. IV. REGULATIONS The city of Boulder first adopted floodplain regulations in 1969, in response to Front Range flooding events which demonstrated the flood potential and need for protective measures within the community. The Flood Control and Drainage Utility was established in 1974. The city's curY•ent floodplain regulations are designed to address the separate issues of life safety, floodwater conveyance, property protection and compliance with the minimum standards established by the Federal Emergency Management (FEM A) for inclusion in the National Flood Insurance (NFIP). The city's floodplain regulations are specifically designed to place a major emphasis on life safety by identifying those portions of the floodplain where an unacceptably high safety risk exists for Boulder residents and visitors. These regulations provide a mechanism for restricting human exposure to flood hazards. The current floodplain regulations were adopted by Ordinance 5199, dated June 27, 1989, and establish three specific flood zones used to manage and regulate development and uses within the floodplain. These zones include the floodplain, conveyance zone and high hazard zone. Under the floodplain regulations, restrictions are applied to development and use in each flood zone. The regulations apply to all properties located within the 100-year (1% based) floodplain, which also includes the conveyance and high hazard zone areas. A floodplain development permit is required for all development within the floodplain, to document compliance with the floodplain regulations. Projects impacted by multiple flood zones (100-year, conveyance, high hazard) must meet the requirements of all applicable zones. A. Floodplain The Fooodplain -defined as all land areas subject to inundation by flood waters. The adopted regulatory floodplain is based on a predicted flood which has a one percent (1%) chance of being equaled or exceeded in any given year. The area predicted to be flooded by a 1% base flood is commonly called the 100-year floodplain. Page 5 Development in the floodplain is permitted only upon demonstration that all proposed structures and additions incorporate flood protection measures, which are intended to mitigate the risk of property loss or damage resulting from the 100-year flood. In residential applications, this requires that the lowest floor of any structure be elevated and placed at or above the flood protection elevation, which is defined as two feet above the projected flood water surface elevation of the base flood. Before a structure is approved for occupancy, an elevation certificate prepared by a licensed surveyor is required to confirm compliance. In non-residential applications, the lowest floor of any structure must be elevated to the flood protection elevation, or be flood-proofed (allowing the lowest floor to be placed below the flood protection elevation) such that the structure is watertight with walls substantially impermeable to the passage of flood waters below the flood protection elevation. New structures must be flood- proofed in a manner requiring no human intei•~~ention. Existing structures may be flood-proofed using human intervention (consisting primarily of flood shields or gates). Before a structure is approved for occupancy, an elevation certificate prepared by a licensed surveyor and/or a floodproofing certificate prepared by a licensed engineer or architect is required to confirm compliance. In general, all uses are allowed in the floodplain, with restrictions on the storage of hazardous materials and moveable objects. New parking lots are not permitted in the floodplain where flood depths would exceed eighteen (18) inches, which is the flood depth at which automobiles may become buoyant. B. Conveyance Zone The Conveyance Zone -determined by simulating a narrowing of the floodplain width from both edges until the depth of flow increases by six inches. The conveyance zone represents a preservation corridor for passing flood flows along the creek corridor, without redirecting flood waters onto or adversely impacting land areas located outside of the adopted floodplain. The conveyance zone is based on the FEMA "floodway" regulation (which allows for a maximum one-foot increase in flood water depths), but uses the more restrictive 0.5- foot flood water depth increase criterion. Development in the conveyance zone is further restricted in that the establishment of any use, or placement of any structure or obstruction, may not create any rise in flood water elevations. This is intended to preserve the conveyance of flood waters without adverse impact on adjacent lands. Applicants for projects in the conveyance zone must provide a hydraulic analysis prepared by a licensed engineer to demonstrate compliance with applicable regulations. C. High Hazard Zone (HHZ) The High Hazard Zone (HHZ) -areas of the floodplain where the combination of depth and velocity are expected to be too great for persons to travel on foot. Areas where the flood velocity (in feet per second) multiplied by the flood depth (in feet) is greater than four or where the flood depth exceeds four feet are considered to be high hazard areas. Page 6 Development in the high hazard zone is most restricted, based on life safety considerations. No new structures or additions to existing structures intended for human occupancy are permitted in the high hazard zone, recognizing the extreme flood risk for potential occupants. In addition, no new parking lots and no change in use of an existing structure from anon-residential use to a residential use are permitted. Some agencies apply regulations to the floodway in a similar manner as the HHZ. The HHZ is unique to Boulder and was adopted instead of a no-build floodway due to extensive development that had already occurred in the floodway, and based on the city's decision to apply anon- containment approach to floodplain management and avoid channelization of Boulder Creek. Furthermore, there is an inability to demonstrate that the hazard to life safety in the floodway would justify the impact on private property rights. D. Substantially Damaged Structures The city's floodplain regulations permit remodeling or rebuilding of flood damaged structures only under certain conditions. A floodplain regulation with great implication for property owners is the provision that buildings that are "substantially damaged" (beyond 50% of their value) within the high hazard zone may not be rebuilt. Property owners with flood insurance would be eligible for some compensation for the loss of their structure and its contents. The city anticipates that it will play a role in compensating property owners for the value of their land if reconstruction is prohibited For "substantially damaged" floodplain buildings located outside of the high hazard zone, regulations require that reconstructed buildings be brought into conformance with the current floodplain regulations. Residential structures would be particularly difficult to bring into compliance as elevation of the lowest finished floor would be required. With the exception of high hazard zone properties, the substantial damage provision applies not only to damage caused from flooding, but also fire, earthquakes, wind, rain or other natural or human-induced hazard. E. Floodplain Development Permit Process Any development within a regulatory floodplain requires authorization in the form of a floodplain development permit. The permit review process ensures that all development-related changes to the floodplain, including filling or grading, construction of new structures and improvements to existing structures, comply with the city's requirements. The review process involves assessing the accuracy and completeness of the application, evaluating site plans, topographic data, building design plans and other technical data, identifying deficiencies, and issuing or denying permits. Each portion of the floodplain zone has different restrictions for development and review processes associated with them. Currently, the permit decision authority for a project in the 100-year floodplain is delegated to the city manager, while permits for development in the conveyance and/or high hazard zones are subject to call-up by the planning board following a decision from the city manager. Variance requests are also subject to call-up by planning board. F. Local Map Amendment and Flood Restudy Process As stated above, site development restrictions can be significant under current floodplain conditions in areas within the conveyance and high hazard zones. In some cases, conveyance and mitigate Page 7 high hazard conditions. Current city regulations and policies allow for site re-grading and modifications to reduce flood impacts. Modifications to relocate the 100-year floodplain require approval from FEMA in the form of a Letter of Map Revision or Physical Map Change, while changes to the extent of the high hazard or conveyance zone is subject to city approval in the form of a Local Map Amendment and is authorized to be amended by the city manager. The Department of Public Works continuously updates and revises the city's floodplain mapping studies along major drainageways, i.e. Boulder Creek and its tributaries, as flood channel improvements or other corrections are made. Because these updates have the potential to impact large sections of the city, the current process for adopting new floodplain mapping studies focuses on outreach and education of affected property owners. The intent is to provide a process that is understandable and acceptable to the community in order to adequately address community concerns, obtain public feedback and minimize the concerns associated with past floodplain mapping changes. The process for adopting new floodplain mapping studies is based on providing extensive community outreach and education in order to obtain public review and comment up-front in the adoption process prior to submitting new mapping studies to FEMA. This approach is intended to address community issues and concerns and provide the opportunity for the public to fully understand floodplain changes before they officially occur on a regulatory map. The process includes the following steps: I) Floodplain Mapping Study Preparation 2} Direct Mailing Notification of Residents and Property Owners Affected 3) Public Meetings for Community Review and Input 4) Compilation and Review of Public Feedback 5) Water Resources Advisory Board (WRAB) Review and Recommendation 6) Planning Board Review and Recommendation 7} City Council Review and Approval to Submit New Floodplain Mapping Studies to FEMA and Adoption of Interim Regulations 8) FEMA Application and Review for Mapping Adoption 9) Local Map Adoption Following FEMA Approval G. Competing Community Objectives The extent and location of floodplains in the city often creates situations in which protection of the public from flood hazards must be balanced with other community objectives. The Foothills Housing project in North Boulder provides an important affordable housing resource located within the floodplain for Fourmile Canyon Creek. Recent downtown projects such as One Boulder Plaza and the St. Julien Hotel contribute to the city's economic vitality, while relying on mechanical flood protection systems to reduce risk. Projects like the Boulder Community Hospital, Twenty Ninth Street, and the Peloton have been allowed to modify the floodplain to improve the development potential of their property. The city will continue to faced be with competing objectives in the future. The proposed annexation of the Pancost-Hogan property in southeast Boulder would provide a valuable housing resource, but would place numerous new structures in the floodplain. The city is currently working Page 8 with Boulder County and the Gapter Road neighborhood on an annexation package to address wastewater disposal issues in this area. A number of the structures to be annexed would be designated as high hazard under city regulations. Efforts to bolster economic vitality by proposing a convention center/hotel in the downtown area (SE corner of 13th and Canyon) will need to consider the impacts of the floodplain, high hazard zone, and conveyance zone on development options. V. NATIONAL FLOOD INSURANCE PROGRAM (NFIP) A. National Floocl Insurance Program The National Flood Insurance Program (NFIP) is a federal program which enables property owners to purchase flood insurance. It was established by Congress through passage of the National Flood Insurance Act of 1968, and is operated under the jurisdiction of the FEMA. This flood insurance is designed to provide an alternative to federal disaster assistance for property damage caused by floods. Flood insurance is generally unavailable through most private-sector insurance companies. There are currently 2,000 federally backed flood insurance policies in effect in Boulder, which is the greatest number for any Colorado community. The intent of the NFIP is to encourage communities to enact and enforce floodplain regulations. The NFIP functions based on an agreement between a local community and the federal government. NFIP provides federally subsidized flood insurance for the community when the community implements measures to reduce future flood risks. Local community measures required under the NFIP agreement include floodplain regulations, master planning and drainageway improvements that provide a means to reduce potential flood losses. The NFIP has established minimum standards that must be implemented to participate in the program, and encourages and supports more restrictive standards where human safety requires additional measures. Community participation in the NFIP is voluntary. However, in order for a property to be covered by a federally subsidized flood insurance policy, the community must participate in the NFIP. The city of Boulder joined the NFIP in 1978, and has continued to participate since that time. This participation makes flood insurance available to all property owners in the community, whether the property is located inside or outside of the floodplain limits, and provides increased potential for federal disaster assistance in the event of catastrophic flooding. For the city of Boulder to remain a participant ofthe NFIP, the city must fully enforce all of the provisions of its floodplain ordinance. If the city fails to fulfill its NFIP obligations to the federal government and allows non-compliant construction, the community impact can be severe. Insurance on an improperly constructed new building may be very expensive, new buildings will be built subject to flood damage, and FEMA can impose "sanctions" to encourage compliance and enforcement. According to federal regulations, a community that does not j oin the NFIP, has withdrawn from the program, or is suspended from it, faces the following sanctions: • Flood insurance will not be available and existing flood insurance policies will not be renewed. • No federal grants or loans for development may be made in identified flood hazard areas under programs administered by Federal agencies, such as HUD, EPA and SBA. Page 9 • No federal disaster assistance may be provided to repair insurable buildings located in identified flood hazard areas for damage caused by a flood. • No federal mortgage insurance or loan guarantees may be provided in identified flood hazard areas. This includes policies written by FHA, VA and others. • Federally insured or regulated lending institutions, such as banks and credit unions, must notify applicants seeking loans for insurable buildings in flood hazard areas that there is a flood hazard and that the property is not eligible for federal disaster relief. To ensure compliance, Community Assistant Visits (CAV) and Community Rating System (CRS) verification visits are conducted by the state and FEMA periodically. Boulder's most recent CRS verification visit was in December 2406. B. Community Rating System The NFIP has also established a Community Rating System (CRS) for flood insurance, initiated in 1990. The objective of the CRS is to reward communities doing more than the minimum NFIP requirements to prevent or reduce flood losses, and provide incentives for communities to initiate new flood protection programs. Under the CRS, flood insurance premium rates are adjusted to reflect increased community activities to reduce flood damages. This may include managing development in areas not mapped by the NFIP, protecting new buildings beyond the minimum NFIP protection levels, helping insurance agents obtain floodplain information, implementing acquisition programs for flood-prone properties, establishing early flood warning systems, producing advanced floodplain mapping, offering floodplain education programs and helping people obtain flood insurance. The CRS operates under apoint-type rating system which, in turn, results in a community receiving a specific Class rating. A Class 1 rating means the community may receive a 45 percent reduction in insurance premiums, while Class 10 rating does not receive any reduction. Currently, only a handful of communities in the nation have received a rating less than Class 8. The city of Boulder is currently rated a Class 8, which offers a 10 percent reduction in the flood insurance premiums paid by policy holders in the city. The city of Boulder's adopted floodplain regulations exceed the minimum standards established by FEMA. Notable floodplain regulations which exceed FEMA standards include: the high hazard zone, which prohibits constructing structures in the most hazardous areas of the floodplain; the flood protection elevation, which requires two feet of elevation above the flood water surfaces (FEMA required zero feet of elevation); the conveyance zone, which limits floodplain encroachment to a 0.5 foot rise (FEMA required requires protection of a one-foot rise floodway), and; flood-proofing requirements, which allow no human intervention for new non-residential structures. Page 10 There are 1,049 communities in the CRS with a Class 9 rating or better, representing 67 percent of the NFIP's policy base. As of October 1, 2007, CRS communities by class were: Class 9 = 303 Class 6 = SO Class 3 = 1 (King County, WA Class 8 = 420 Class 5 = 33 Class 2 = 1 (Tulsa, OK) Class 7 = 209 Class 4 =1 (Fort Collins, Class 1 = 1 (Roseville, CA) CO The CRS claims a series of rewards in addition to reduced flood insurance premiums. These include: (a) enhanced local floodplain management, (b) benchmark assessments, (c) federal technical assistance, (d) incentive-based program maintenance, and (e) qualification for federal assistance programs. Primary credit categories include public information activities, mapping and regulations, flood damage reduction activities and flood preparedness activities. The CRS awards points in four major categories: ¦ ACTIVITY 300 -Public Information Activities ¦ ACTIVITY 400 -Mapping & Regulatory Activities ¦ ACTIVITY 500 -Flood Damage Reduction Activities ¦ ACTIVITY 600 -Flood Preparedness Activities Boulder entered the CRS based on progressive local flood management programs that have been put in place over the years. The city initially received a Class 9 rating in 1992, offering a five percent reduction in annual flood insurance premiums. In 1997, the city was able to improve to a Class 8 rating with a 10 percent reduction in local premiums. While Boulder performs numerous activities that would earn CRS credit, we have not been able to take full advantage of this program given the great deal of documentation and dedicated staff resources needed to apply for and maintain a higher rating. The Comprehensive Flood Study (CFS) recommended making a greater commitment to the CRS as part of our Flood Management Program. Public Works contracted with nationally known French & Associates, LTD, in 2005 to identify actions that could help Boulder receive a higher CRS Class. Based on the results of the most recent Cycle Verification Visit, the city received a class upgrade to a Class 7, which provides a 15% discount on flood insurance premiums. It appears that the Flood Management Program is close to earning enough credits for a Class 6, and should accomplish this with the anticipated completion of the Multi Hazard Mitigation Plan and South Boulder Creek Restudy in 2008. The city will be pursuing a better rating (6 or 5) as part of next year's CRS recertification. If so, flood insurance premiums could be reduced by 20-25 percent. If this cannot be achieved, the city may want to reassess the CRS commitment to determine if seeking a higher classification offers the best benefit as compared with other Flood Management Program elements. VI. CURRENT FLOOD STUDIES AND MAPPING PROJECTS The city's Stormwater and Flood Management Utility undertakes technical studies of flood hazard areas on an ongoing basis. Notable recent study areas include South Boulder Creek, Fourmile Page 11 Canyon/Wonderland Creek, Gregory Creek, and Goose Creek. Studies generally consider both hydrology (how rainfall is likely to occur and runoff the landscape) and hydraulics (how runoff is likely to be conveyed). Studies generally result in updated mapping for regulatory purposes and may result in capital construction projects to mitigate flood hazards. There are several high profile studies and projects that are being implemented as follows: A. Fouimile Canyon and Wonderland Creeks Flood Mitigation Planning In the fall of 2000, City Council provided direction regarding the Fourmile Canyon Creek Flood Mitigation Plan based on city staff and Independent Review Panel recommendations. A draft Phase B (preliminary design) plan was delivered by the consultant Love & Associates in September 2001. Further Independent Review Panel comments suggested that an additional alternative be considered prior to developing a final design plan. The additional alternative involved investigating floodproofing of existing structures. The city and the Urban Drainage and Flood Control District (UDFCD), working with Love & Associates, completed the floodplain mapping restudy for both Fourmile Canyon Creek and Wonderland Creek basins under current conditions. The results of the mapping went through an extensive public review process and were submitted to FEMA in early 2006. FEMA approved the study results in March 2007, and they are now the basis of future regulation and insurance requirements. The revised Major Drainageway Planning - Phase A Report -Alternatives Analysis (Phase A Report), addressing floodproofing of existing structures, was completed by the consultant Love & Associates and provides revised recommendations to the city regarding the flood mitigation plan. Utilities Division staff has coordinated the flood mitigation planning with the Greenways Program and the North Boulder Subcommunity Plan (NBSP) and has provided additional recommendations. The Phase A report along with staff recommendations have been accepted by both the Greenways Advisory Committee (GAC) and the Water Resources Advisory Board (WRAB). Following acceptance of the proposed flood mitigation plan by the Planning Board, the plan will be presented to City Council. Contingent on City Council acceptance staff will work with Love & Associates to further develop the proposed plan as part of Phase B -Preliminary Design. The preliminary design will be reviewed as part of the city's Community and Environmental Assessment Process (LEAP). It is anticipate the public involvement process for this phase of the project will begin in late 2008 and be completed in early 2009. IVloney has been budgeted in the 2048-2013 Capital Improvement Program (CIP} budget to begin to fund selected flood mitigation work and associated property acquisition. It is likely complete implementation of the selected flood mitigation plan will take several decades to complete. For more information regarding the Fourmile Canyon and Wonderland Creek flood mitigation planning project go to: httpa/ww~~~.bouldercolorado.~ov/index.php?option=com content&task=view&id=4976&Itemid=21 44 Page 12 B. South Boulder Creek Flood Mapping Study The South Boulder Creek (SBC) Flood Mapping study is intended to replace the current regulatory mapping that is based on a 1986 United States Army Corps of Engineers (USAGE) study. The 1986 study is currently adopted by the city, Boulder County and the Federal Emergency Management Agency (FE11~IA) and is used for all present regulatory purposes. The SBC Flood Mapping study is intended to "define the flood problem, not solve it. " The key issues in the study are to develop scientifically defensible results based on sound technical analysis and offer adequate community outreach to educate and inform the public in order to achieve clear understanding and acceptance of the study outcome. Flood A~lappin~ Submittal to FEA~IA: The city's participation in the National Flood Insurance Program requires that new information concerning flood hazards be submitted to FEMA within six months after the information has been developed. City Council authorized the city manager to submit the SBC Flood Mapping study to FEMA on April 17, 2007. Minor modifications to the reports and flood hazard mapping were made based on additional ground survey information presented by the city and property owners prior to submittal to FEMA. The study results were submitted to FEMA for approval in August 2007. Initial comments from FEMA have been mostly positive. It is anticipated the FEMA total review period will take nine to 12 months. FEMA will also solicit public comment as part of their review process. Provided FEMA accepts the study results, the Colorado Water Conservation Board will be also be asked to adopt the study results and associated flood hazard mapping. Risk Assessment and Flood 1Vliti~ation Planning: The risk assessment was completed during 2007 in order to support subsequent flood mitigation planning. Flood mitigation planning will begin as soon as practical after the flood study results have been accepted by FEMA, Boulder County, the city of Boulder and other agencies. Currently, funding has been included in the city's CIP in 2007 and 2008 to complete the flood mapping project and the flood mitigation planning effort. Also, $3,000,000 has been proposed in 2010 to help fund selected flood mitigation improvements, whatever these might be. The city is also pursuing federal funding for the cost of flood mitigation planning and flood mitigation projects (construction). It is anticipated that the focus of these efforts would be to primarily mitigate the impacts of flooding in the West Valley, where flood impacts were previously not identified and substantial urban development has since occurt•ed. It is important that flood mitigation planning efforts proceed concurrently with the U.S. 36 Corridor Improvements-Environmental Impact Statement. For more information regarding the South Boulder Creek Flood Mapping Study go to: http:;`/www.bouldercolorado.gov/index.php?option=com content&task=view&id=6527&Itemid=ll 89 Page 13 C. Elmer's Twomile Creek -Goose Creek to Glenwood The Elmer's Twomile Creek project is being implemented under the city's Greenways Program and includes agrade-separated, multi-use path connection from Goose Creek to Glenwood Drive, an underpass at Valmont Road and flood mitigation improvements. Flood mitigation along Elmer's Twomile will address flooding that would occur south of Glenwood Drive to the confluence with Goose Creek during a 100-year storm event. Several properties east of the Elmer's Twomile channel and west of 28th Street are currently in the 100-year conveyance zone. Portions of these properties are also in the high hazard zone. Shallow flooding would also occur east of 28th Street. This project would remove these properties from the 100-year floodplain by containing the flows within the Elmer's Twomile channel (or a box culvert). In addition, a CLOMR/LOl~IR analysis will be completed as part of this project in order to update the floodplain delineations along the creek. The Elmer's Twomile project is being funded through the Flood CIP (2005-2009) totaling $3.0 million and the Greenways CIP (2005-2008) totaling $713,000. Federal Transportation Improvement Program funding ($3.2 million) has also been approved, as well as Urban Drainage and Flood Control District funding. As part of the federal funding process, Right of Way (ROW) plans were developed that show the need to acquire 22 easements from nine properties in order to complete the project. Because of the number of easements required and the number of individual property owners involved, condemnation may be required. For more information regarding the Elmer's Two-mile Creek -Goose Creek to Glenwood project go to: http:;`h~vww.bouldercolorado.gov,~index.php?option=com content~itask=view&id=6527&Itemid=ll 89 D. Goose Creek The Goose Creek Restoration project continued to receive funding for 2008 fiom the federal government allowing the Corps of Engineers to continue work on a feasibility study for restoring Goose Creek downstream of Foothills Parkway to the confluence with Boulder Creek through the Cottonwood Ponds. This project will incorporate habitat functions into the current channel design which primarily supports flood conveyance. The U.S. Army Corps of Engineers identified two conceptual alternatives for the Lower Goose creek restoration as part of the draft Feasibility Report. During 2007, the Greenways Advisory Committee provided feedback on these conceptual alternatives as part of the public involvement and scoping process. Meetings were also held with adjacent property owners. Based on feedback from these meetings, a conceptual alternative was chosen for the final Feasibility Report. The preferred alternative involved shifting the existing bike path south in order to widen the Goose Creek riparian zone just upstream of Cottonwood Pond. In addition, the city of Boulder is working «~ith the Army Corps of Engineers to expand the feasibility study to look at improving a section of Goose Creek as it traverses the Transit Village area. The area-wide management of stormwater proposed in the Transit Village Area Plan would work together with the restoration of Goose Creek for improved habitat and and water quality. With the addition of the Transit Village segment, completion of the Feasibility Study is anticipated in 2009. Page 14 E. Boulder Creek Flood A~Zappnig Project The study will develop an updated, comprehensive floodplain map for Boulder Creek from the mouth of Boulder Canyon (western city limits) to downstream of 63'~d Street. The numerous changes and improvements that have occurred along Boulder Creek since the currently regulatory model was prepared by Muller Engineering in the early 80's will be incorporated into the new study. Upon completion of the updated hydraulic analysis, the results will he used to evaluate scenarios for redeveloping aconference/convention center in the downtown Boulder area of the Boulder Creek floodplain (between 13~' and 14th Street and Arapahoe Ave and Canyon Blvd). A review and evaluation of existing flood control levees/floodwalls will also be completed for possible FEIVIA certification of the levee structures at 75th Street Wastewater Treatment Plant and the Canyon Point Levee between 6th and 9th Street. F. Gregory Creek Flood Mapping Project In late 2006, a Letter of Map Revision was completed to update the Gregory Canyon Creek floodplain and to include improvements and changes along the Creek that have occurred since the current regulatory study was adopted by FEMA in 1987. The results of the study indicate that there are approximately 8 properties `new' to the high hazard zone that are not currently located in the regulatory floodplain. Prior to moving the study forward through public process for adoption, Utilities staff is working with Love & Associates to evaluate high hazard zone mitigation options for the 8 `new' properties that are located in the proposed high hazard zone. G. Qtlier Flood Mapping Projects Floodplain mapping studies provide the basis for flood management by identifying the areas subject to flooding. This information is essential in determining areas where life safety is threatened and damage to property is likely. Floodplain mapping studies need to be updated periodically to reflect changes in the floodplain resulting from land development, flood mitigation improvements, new study technologies and the impacts of major flooding. In addition to the flood mapping update components of the projects mentioned above, several other flood mapping projects have been initiated. The new studies v~~ill replace the current flood mapping studies that are more than 15 years old. Bear Canyon Creek -Revisions to the current flood mapping will be made based on the improvements at Foothills Parkway and Arapahoe Ave., including the construction of the new pedestrian underpass that also has flood mitigation benefits. Skunk Creek -Revisions to the current flood mapping will be made based on the improvements at Baseline Road and 27th Way, including the construction of a new pedestrian underpass that also has flood mitigation benefits. Wonderland Creek -Revisions to the current flood mapping will be made based on the improvements to the crossing at the Diagonal Highway, including the construction of a new pedestrian underpass that also has flood mitigation benefits. Page 15 H. Digital Flood Insurance Rate Maps (DFIRMS) Boulder County was selected to undergo a DFIRM conversion process in 2005 as part of FEMA's Multi-Year Flood Hazard Identification Plan (MHIP). The 2004 MHIP details afive-year plan for map modernization in support of NFIP objectives to provide reliable digital flood hazard data and maps for the United States. A DFIRM is a digitally based Flood Insurance Rate Map (FIRM) that can be delivered in a Geographic Information System (GIS) format and made available online. Advantages of the DFIRIVI format include improved data quality and map accuracy, direct accessibility and sharing of information to improve public understanding and awareness, frequent updating to reflect incremental map changes between formal FIRM adoption schedules, and the capability to be assembled together (in a "tile-by-tile" map format) across the United States. The most positive aspect of the DFIRM conversion for Boulder is achieving consistency between the regulatory floodplain mapping stored on the city's GIS system and the federally adopted mapping. The traditional paper FIRMS that have been in place since 1978 often reflected discrepancies in floodplain boundaries given transcription of detailed study maps to a large scale, one-inch-equals-one thousand feet federal snap. Boulder's DFIRM project will simply convert existing FIRM panels to the GIS format and will not change currently adopted federal floodplain mapping studies. This simple conversion precluded a need for extensive public review, similar to those performed when adopting new and updated floodplain mapping studies. Given this, several flood mapping studies in progress for Fourmile Canyon Creek, Wonderland Creek and South Boulder Creek will require separate adoption processes for incorporation into the DFIRM. The final DFIRM is dependent on the certification of levees within the City. This process requires documentation of the levee freeboard, geotechnical analysis, and operation and maintenance plan in addition to a professional engineer's signature. Levee certification work is currently underway. The NFIP also requires communities to reference the DFIRM in local floodplain ordinances by the effective date. A city code revision adopting the 2006 DFIRM ~~ill involve a minor change as follows to reflect the new effective date. Council approval of the DFIRM conversion will be sought later this year. VII. PROPERTY ACQUISITION PROGRAM The pre-flood property acquisition fund is used for purchasing properties that are currently in a hazardous area of the 100-year floodplain and have the probability of experiencing severe damage during a major storm. The fund may also be used to purchase properties that are needed for flood mitigation work. Owners of several high priority properties have been contacted regarding the city's purchase interest. Over the last 15 years, the city has focused its flood management program efforts by removing structures fiom high hazard flood areas. Through these efforts, 134 of 279 identified high hazard structures have been removed fiom the regulated high hazard flood zone. This was accomplished Page 16 based on a combination of major drainage«~ay improvements that narrowed the floodplain and/or the acquisition and physical removal of individual structures. A project that acquired and physically removed 13 multi-family structures (169 units) near Boulder High School is a major example of these efforts. This project also excavated the area north of Boulder Creek (now recreational/sports fields) to improve flood conveyance. The city's Comprehensive Flood & Stormwater Master Plan (CFS) proposes to continue these efforts, balancing property acquisition and constructed flood mitigation projects. Additional structures were purchased and retnoved from the floodplain during 2446. The post-flood property acquisition fund is intended to be used to purchase properties whose structures sustain significant flood damage within the designated high hazard flood zone. City ordinance does not allow redevelopment of properties whose structures have sustained flood damage greater than 54 percent of the value of the structure. Currently $1,454,444 is reserved in the Stormwater and Flood Management Utility fiend balance for the purpose of purchasing such properties. Given the relatively limited level of funding, this money would likely be used to leverage available state or federal disaster relief funds following a major flood event. This will be an issue if and when a major flood occurs since this will be a major financial hardship for property owners unless the city has the ability to provide relief by purchasing the properties through the post- flood property acquisition program. VIII. FLOOD PREPAREDNESS Flood preparedness is a critical element in the city's floodplain management program, considering the significant number of structures, including dwellings, which are located in the floodplain. Flood monitoring and warning must provide notification in an extremely timely manner, given that 24 minutes may be all that can possibly be provided from a flood warning to critical human response. The more prepared a community can be with pre-flood preparedness, ongoing monitoring, effective warning systems, trained response, and post-flood recovery, the better chance the risks of flooding may be managed. The city of Boulder and Boulder County developed a flood monitoring and warning system in conjunction with the UDFCD in 1979. The system is managed by the Boulder County OfI"ice of Emergency Management (OEM) and is made up of numerous rainfall and stream flow gauges data to assess flood potential.located in the foothills and canyons that telemetry storm. The National Weather Service and a meteorological consultant retained by the UDFCD also provides weather information to assist in predicting flooding. A weakness in the system is the lack of rainfall monitoring gauges inside the city, which could provide data for smaller drainage basins and creeks. Boulder's flood warning plan is updated annually along with an annual exercise and monthly tests of the siren system in the summer months. The UDFCD provides maintenance funding for the flood warning (ALERT) system. Under the system, city and county officials work together using the procedures outlined in the Boulder Creek Flood Warning Plan (2443} and the Emergency Operations Plan -Bouldet~ County and City ofBoulder (1998) to determine if a flood warning is warranted, disseminate any necessary warnings, and respond to flooding accordingly. Page 17 Flooding places lives and property at risk and a community's ability to respond inay be the deciding factor to reduce those risks. It takes tune for emergency response agencies to set up and prepare for an organized response, and damaged roads and disrupted communications systems may restrict their access into critically affected areas. Individual preparedness, planning, survival skills and mutual aid within neighborhoods and worksites during this initial period are essential measures in coping with the aftermath of a flood. No community wants to be faced with the daunting task of disaster recovery. However, many disasters are followed by the largest infusion of federal, state and local recovery capital that will ever occur at one time. Communities with up-to-date response plans can clearly and quickly identify and articulate their needs to state and federal officials. These communities will have a competitive edge when post-disaster funding and technical assistance are needed. Currently the emergency manager has access to sirens, radio, cable oven•ide and a "911-type" callback system. Boulder should institute a procedure that will reach a maximum number of residents both indoors and outside that is equally effective both during the day and at night. The current flood response plan provides step-by-step procedures for public officials to follow during the early stages of a flood. The response plan is comprehensive; however, modifications to the plan are recommended, such as providing procedures for daytime response and nighttime response. Emergency plans must address necessary recovery elements as well, such as identifying early actions and decisions that must be made, meeting victims' immediate needs, performing building and infrastructure damage assessments, re-establishing critical community services, acquiring or preserving post-flood properties to avoid future losses, issuing building permits for allowed reconstruction, and restoring normal city operations. The city is working with AMEC Earth and Environmental, Inc. on finalizing the development of a Multi-Hazard Mitigation Plan (MHMP) for Boulder. The Disaster Mitigation Act of 2004 (DMA}, requires local communities to have a FEMA approved I~IHIVIP in place in order to maintain eligibility for certain federal pre- and post-disaster mitigation funding. The purpose of the plan is to identify natural hazards that affect a community and the people and places that are at risk. The plan then provides a frame~~~ork for actions that may be applied to reduce or eliminate long-term risk associated with priority hazards. MHMP elements include: • Community Profile • Risk Assessment • Hazard Identification • Vulnerability Assessment • Capability Assessment • Mitigation Strategy The Denver Regional Council of Governments (DRCOG) adopted a Denver Regional Natural Hazard Mitigation Plan in October 2003, as initially required under the DMA. Boulder County and the city of Boulder did not formally participate in the DRCOG plan and did not receive MHMP Page 18 credit. The Boulder Flood Management Program decided to initiate the MHMP process independently to preserve our federal mitigation funding eligibility. The University of Colorado (CU) has also adopted a MHMP under a federal Disaster-Resistant University grant. CU started their process with federal grant funding prior to the city's action. In addition, Boulder County has recently initiated their MHMP and the City plans to partner with them in order to combine the regular 5-year updates under one plan. The City of Boulder MHMP has been presented to WRAB and is currently under final review by FEMA. It is anticipated the plan will be presented for formal adoption by Council in May. IX. FLOOD EDUCATION The city of Boulder and the UDFCD co-funded an Internet-based flood education project for Boulder in 2~t~4, found at http:/,/F1oodSafety.com/colorado/index.htm and http://www.boulderfloods. org The project was developed by Marshall Frech, Texas Environmental Center (TEC) and is an expansion of the Web site originally developed to address major flooding in Texas. Phase 1 involves interactive maps, an introductory video, front-range flood history, and information about clean-up after a flood. Given the Phase 1 results and the value of expanding the availability of flood education, the city and UDFCD have co-funded a Phase 2 of the project. In addition, TEC is seeking funding from multiple resources to expand the Web site to cover the entire Front Range. Expected products from the Phase 2 project include: • "Ready or Not," a PBS movie about Front Range flooding • Flood Animation Maps • Watershed IVlaps • Short V ideos of Municipal Projects and Flood Safety Issues • Flood Insurance Facts • Public Safety Personnel Orientation and Training DVD • Front Range Weather videos • National Attention for Boulder's Flood Risk In addition to the floodsafety.com website, staff continues to develop and expand the city's floodplain management Web page www.boulderfloodinfo.net. The site focuses on educating the public about floodplain management activities and information, including access to common flood information such as flood elevation certificates and Letters of I~~Iap Change that have been issued by FEMA. The annual flood utility bill insert that provides flood information will also be improved this year to meet conditions for scoring higher under the CRS. Page 19 X. CRITICAL FACILITIES REGULATIONS City Council endorsed the development of higher floodplain standards for critical facilities at its January 29, 2002 Floodplain Policies study session. The CFS adopted in 2004 also prescribed the development of 500-year protection standards for critical facilities, in line with Federal guidance, to ensure access to, use of, and uninterrupted service for critical facilities. The 2006 Boulder Valley Comprehensive Plan, Implementation Plan, Section 4.20-4.24, "Floodplain Policies," outlined the implementation of a critical facility floodplain ordinance: Short Term (1-2 Years) AZid Primary Status 2006-2007 Term (3-5 Responsibility Years) Zoos-2aio ~ Environment 4.20 - Develop a critical facility floodplain LJtilities, These 4.24 ordinance for the city to protect Planning efforts are Floodplain critical facilities to the X00 year flood. set to move Policies Expand risk assessment activities to forward include: immediate) • 500 year floodplain risk assessment y with (population and structures). city's • High Hazard floodplain risk consultant assessment (population and providing structures). research • Hazard analysis of identified critical and facilities using available data. recommend • Additional inventory and analysis of a-tions. 100-year, 500-year, and High Hazard floodplain to include # of acres, # of parcels improved and vacant, and vacant parcel Land Use and Zoning designations. The location of critical facilities is a major concern in any disaster event. Critical facilities are essential to the community in serving and protecting the public and maintaining continuity of government and the economy before, during and after a disaster. Critical facilities located in the floodplain are placed at a higher risk for loss and ensuring their protection may be vital in an emergency. The f°irst element in developing a critical facility ordinance is def°ining critical facilities. Commonly accepted critical facilities include f°ire and police stations, water and sewer treatments plants, utility infrastructure for ~~~ater, sewer, gas, electric and communications, hospitals, nursing homes, and facilities storing hazardous materials. Others may be schools, publicly-owned facilities and designated emergency shelters. Page 20 AIVIEC Earth & Environmental, Inc. is assisting the city in researching and developing a critical facility ordinance. AMEC's June 16, 2006 memo outlines research of critical facility regulations nationwide acid has led to a recommendation for defining local critical facilities as follows: "Critical Facility" means any property that, if flooded, would result in severe consequences to public health and safety or a facility which, if unusable or unreachable because offlooding, would seriously and adversely affect the health, safety and welfare of the public. Critical facilities include, but are not limited to: (1) Schools and other publicly-owned facilities, (2~ Hospitals, nursing homes and housing likely to have occupants who may not be sufficiently mobile to avoid injury or death during a food, (3) Police stations, fire stations, vehicle and equipment storage facilities, and emergency operations centers and designated shelters that are needed for flood response activities before, during and after a flood, (4) Public and private utility facilities that are vital to maintaining or restoring normal services to flooded areas before, during and after a flood, and (S) Structures or facilities that produce, use or store highly volatile, flammable, explosive, toxic and/or water/reactive materials. Staff is currently researching and evaluating floodplain regulations and measures for application to critical facilities. Some options that maybe considered include, prohibiting new critical facilities in flood hazard areas, requiring substantially unproved structures to be flood protected to the 500-year flood level (this will also require an analysis of appropriate freeboard requirements), and road access standards to ensure connection to lands outside the 500-year floodplain. Conceptually, the regulations would apply protection standards to facility development deemed critical based on the 500-year event water surface elevations, instead of 100-year event water surface elevations currently used to regulate both critical and more general development. Current floodplain regulations prohibit use changes in the high hazard zone of existing structures to schools, daycare centers, group homes, residential care facilities or congregate care facilities. Staff will evaluate expanding on this requirement to include other defined flood risks (100-year, 500- year, and conveyance zone) and other types of critical facilities. Amore detailed discussion regarding specific development standards for protecting critical facilities will be presented at a later phase of the project. Ideally, critical facilities would not be located in the 500-year floodplain. However, it is recognized there are a significant number of existing facilities that are within this floodplain. The evaluation will include inventorying these existing facilities and distinguishing their various uses (for example, in the case of various public facilities, the associated agency and the type of use.) Cost estimates for potential mitigation alternatives that provide protection for both the 100-year and X00-year flood event will be developed. The type of facility and the estimated mitigation cost will be used to prioritize facilities for inclusion in the proposed ordinance definition of critical facilities. Approval of a "critical facilities" definition and ordinance will be subject to public review and recommendation by the WRAB and the Planning Board before presenting an ordinance to City Council for adoption. The WRAB will be key in evaluating the benefits and impacts of higher regulatory standards for future application. Page 21 The Implementation Plan above also outlines expanding floodplain risk assessment activities to include the 500-year floodplain. This expanded assessment will be used to define the effectiveness of current floodplain standards and offer an understanding of the impacts that would be associated with increasing floodplain standards to the 500-year level. Recent disasters and national trends in natural hazard protection standards have raised concerns that the 100-year flood standard may not offer adequate protection for losses. Minor regulatory changes, specifically related to clarifying the current code, may also be evaluated through this process, and if needed, ordinance changes will be forwarded to City Council as part of the critical facility regulations. ATTACHMENT A - CFS Master Plan Executive Summary ATTACHMENT B -City Council Study Session Outline Page 22 d, ~ E iry ,.7 B~w,J_r ~j G~~ry oaastPt Pia ~ B- I , ' ' ' I ~ I r jj j ~ `a.~. ~ ~ j ~,,,,i±` ~ ate"':- ~ ` "-~-x~ - `~r ,mot. ii .y, a y r ~r' S, . i yy .r" rF _ r ~ _ 4 i _ ~ a~ / 1 • ~ • • - cy\~e Flood d~a ~ City of Boulder ~ V ~ ~ Gfi//fy Master P\a~ . TABLF CAF CCJNTENTS ACKNOWLEDGEMENTS EXECUTIVE SUMMARY ES-1 CHAPTER 1 -THE COMPREHENSIVE FLOOD AND STORMWATER AND UTILITY MASTER PLAN 1-1 1.1 Overview 1-1 1.1.1 Enterprise Utility 1-4 1.2 Background ..................................................................................................1-4 1.2.1 Utility History 1-4 1.2.2 Area Description 1-7 1.2.3 Growth and Development 1-8 1.2.4 Current Program Descriptions 1-8 1.3 Public Process 1 -1 1 1.3.1 Master Plan Process 1-1 1 1.3.2 Development of Review Information 1-13 CHAPTER 2 -POLICIES, TRENDS, AND GUIDING PRINCIPLES 2-1 2.1 Existing City Policies 2-1 2.1.1 Flood Management Policy Critique 2-5 2.1.2 Stormwater Management Policy Critique 2-8 2.1.3 Policy Integration 2-9 2.2 Trends ..........................................................................................................2-9 2.2.1 Flood Management 2-9 2.2.2 Stormwater Management 2-13 2.3 Stormwater and Flood Management Utility "Guiding Principles" 2-13 2.3.1 Flood Management 2-13 2.3.2 Stormwater Quality 2-14 2.3.3 Stormwater Drainage 2-14 I cy\~e Flood d~a ~ City of Boulder ~ V ~ ~ c_ Gf~~~fy Master Qua CHAPTER 3 -FLOOD MANAGEMENT 3-1 3.1 Overview 3-1 3.2 Guiding Principles for Flood Management 3-1 3.3 Recommended Flood Management Program Elements 3-3 3.3.1 Floodplain Mapping Studies Program 3-4 3.3.2 Public Education and Flood Insurance 3-9 3.3.3 Flood Preparedness 3-13 3.3.4 Floodplain Regulations 3-16 3.3.5 Property Acquisition and Floodplain Mitigation 3-20 CHAPTER 4 - STORMWATER QUALITY 4-1 4.1 Overview 4-1 4.2 Guiding Principles for Stormwater Quality 4-1 4.3 Recommended Stormwater Quality Program Elements 4-1 4.3.1 Water Quality Regulations 4-2 4.3.2 Sub-basin Management 4-5 4.3.3 Stream Enhancement 4-12 CHAPTER 5 - STORMWATER DRAINAGE 5-1 5.1 Overview 5-1 5.2 Guiding Principles for Stormwater Drainage 5-1 5.3 Recommended Stormwater Drainage Program Elements 5-1 5.3.1 Stormwater Collection System and Planning 5-3 5.3.2 Design and Construction Standards 5-5 5.3.3 Maintenance 5-6 5.3.4 Detention 5-9 5.3.5 Groundwater 5-12 CHAPTER 6 -PROGRAM INTEGRATION AND IMPLEMENTATION 6-1 6.1 Overview 6-1 6.2 Current Program 6-1 I I cy\~e Flood d~a ~ City of Boulder ~ V ~ ~ Gfi//fy Master P\a~ . 6.2.1 Utilities Division 6-1 6.2.2 Planning and Development Services 6-3 6.3 Key Issues and Analysis 6-3 6.3.1 Current Program Integration System 6-4 6.3.2 Information from Other Communities 6-7 6.4 Recommendations .........................................................................................6-9 6.4.1 Program Integration 6-9 6.4.2 Program Implementation 6-15 CHAPTER 7 -FINANCIAL CONSIDERATIONS 7-1 7.1 Funding Sources 7-1 7.1.1 Monthly User Fees 7-1 7.1.2 Plant Investment Fees 7-3 7.1.3 Other Funding Sources 7-3 7.2 Budget 7-4 7.3 Program Funding Recommendations 7-5 7.3.1 Flood Management 7-5 7.3.2 Stormwater Management 7-6 REFERENCES 8-1 GLOSSARY OF TERMS 4-1 List of Tables Table 3-1 Properties Affected by Floodplain Areas in Boulder January 2002} Table 6-1 Comparison with Other Communities List of Figures Figure 1-1 City of Boulder Basins Figure 3-1 City of Boulder Major Drainageways Figure 3-2 City of Boulder FEMA Floodplains Figure 3-3 City of Boulder Potential Properties for Acquisition with Structures Located within the High Hazard Flood Zone Figure 4-1 City of BoulderSubbasin Pollutant Loading III cy\~e Flood d~a ~ City of Boulder ~ V ~ ~ Gfi//fy Master P\a~ . Figure 4-2 Potential Redevelopment and Water Quality Improvement Sites Figure 4-3 Minimizing Directly Connected Impervious Area Figure 5-1 City of Boulder Irrigation Ditches Figure 5-2 City of Boulder Storm Sewer Mains Figure 5-3 City of Boulder Inventoried Detention Facilities Figure 6-1 Stormwater and Flood Management Utility Organizational Staffing Chart Figure 7-1 Monthly Stormwater Utility Fees for Colorado Municipalities IV ACKNC~WLE©GEMENTS We would like to acknowledge the participation of the following individuals. Their insights, information and discussions and contributed to the accuracy and completeness of the CFS. City of Boulder ? Director of Public Works for Utilities, Ned Williams ? Utilities Planning and Project Management Coordinator, Roberti Harberg ? Transportation and Utilities Maintenance Coordinator, Stephanie Grainger ? Water Quality and Environmental Serrices Coordinator, Chris Rudkin ? Flood Program Manager, Alan Taylor ? Engineering Review Manager, Jeff Arthur ? Stormwater Quality Specialist, Donna Scott ? Senior Supervisor -Transportation and Utilities Maintenance, Felix Gallo ? Water Quality Planner, Betty Solek ? Civil Engineer, Scott Kuhna ? Utilities Project Manager, Douglas Sullivan ? Long Range Planner, Jean Gatza ? Chris Kelley, GIS Technician URS Corporation ? Scott Randall, Project Manager ? Steve Rogers ? Chris Tagert ? Julie Vlier ? Rob Zuber ? Monica Bortolini ? Rich Tocher ? Molly Tayer, Decision-Making Systems October 2004 Independent Review Panel ? Brian Hyde, Project Manager, Colorado Water Conservation Board ? Mary Fran Myers, Executive Director, Natural Hazards Center, University of Colorado ? L. Scott Tucker, Executive Director, Urban Drainage and Flood Control District ? Gilbert White, Professor Emeritus, Social Sciences, University of Colorado ? Ken Wright, Wright Water Engineers Community Review Group ? Jerry Lee, Lee Development /Development Interest ? Bill Mitzelfeld, Scott, Cox & Associates, Inc. /Civil Development Engineer ? Alison Richards, Transportation Interest ? Kathie Joyner, City of Boulder Environmental Advisory Board / Greenways Interest ? Terry Rodrigue, Boulder Urban Renewal Authority /Civil Development Engineer ? Stuart Grogan, Boulder Housing Partners /Affordable Housing Interest ? Peter Gowen, Resident of South Boulder Creek Floodplain Area ? Elizabeth Black, Resident of Fourmile Canyon Creek Floodplain Area ? Jim & Kathy Snow, Residents of Fourmile Canyon Creek Floodplain Area /Silver Lake Ditch ? Ken Hotard, Boulder Area RealtorAssociation /Real Estate Interest ? Phil Simpson, University of Colorado Facilities Management ? Dave Webster, County Public Works Department ? Sara Michl, PLAN Boulder County ? Jeannette Hillery, League of Women Voters ? Joe Howard, Boulder Community Hospital Facilities Management ? Alan O'Hashi, City of Boulder Planning Board ? Charlie Manlove, City of Boulder Parks and Recreation Advisory Board ? Don Mock, City Council /Meteorologist October 2004 Water Resource Advisory 13aard ? Jeannette Hillery ? Gilbert Barth ? Kenneth L. Wilson ? Jim Knopf ? Bart Miller DlSCL4rMERS All rights reserved. The information depicted on maps included in this document is provided as a graphical representation only. The City of Boulder provides no guarantee, express or implied, as to the accuracy and/or completeness of the information contained herein. October 2004 cy\~e Flood d~a ~ City of Boulder ~ V ~ ~ Gfi/'fy Master P\a~ . ~~~~„fTly~ 5~..~1•~~4~~Y ~ Stormwater Quality Management. ~ Emergency Preparedness and Day-to-Day 1NTRODUCTlON Operations. The Comprehensive Flood and Stormwater ~ Capital Improvements and Land Utility Master Plan CFS} provides a framework Management. for evaluating, developing, and implementing various programs and activities in the Utility The CFS Utility Plan's main objectives are to within the scope of the available budget. The address: ~l }flash flood hazards; ~2} stormwater CFS replaces the 1989 Comprehensive quality; ~3} stormwater drainage; ~4} program Drainage Utility Master Plan ~CDUMP}. integration and implementation; and ~5} financial considerations. The CFS is the result of the periodic need to update programs and activities to satisfy DESCRIPTION current local interests, accommodate changing trends, philosophies, regulations and The Boulder Creek Watershed encompasses standards, ensure maximum effectiveness and some 440 square miles and extends from the cost efficiency, and meet evolving community Continental Divide to the high plains east of goals and objectives. the City. There are 15 major drainageways ~or creeks} in Boulder, within which a total of 17 The Stormwater and Flood Management Utility sub-basins have been delineated. The Utility} is responsible for the administration of tributary drainageways all eventually feed to the City's flood management, stormwater Boulder Creek north of the Valmont Reservoir. quality, and stormwater drainage programs. Its responsibilities include: The study area itself is nearly "built out" resulting in a highly urbanized drainage ~ Administration and Operations. setting. The natural hazards related to stormwater and flood management are ~ Utility Rates and Finance. particularly complicated by the fact that space is at a premi um and that so many structures ~ Program Development and Management. are within the floodplain. ? System Maintenance and Restoration. PUBLIC PROCESS ~ Flood and Stormwater Regulation and ACommunity-Review Group ~CRG} was used Compliance. to provide "real-time" input to the analysis and draft recommendations for the CFS Master ~ System Master Planning and Design. Plan. The CRG was created based on the key interests affected by the CFS. ~ Public Education and Community Outreach. The Independent Review Panel ~IRP}, a panel of flood hazard experts, also participated in the ~ Flood Prediction. CFS development process. ES-1 cy\~e Flood d~a ~ City of Boulder ~ V ~ ~ Gfi//fy Master P\a~ . Boulder floodplain policies have not been The Water Resource Advisory Board ~INRAB} updated since adoption of the CDUMP. As a met twice in 2003 and discussed key issues result, our local floodplain management and the master plan process. program has fallen behind the progression of national and regional trends and philosophies, Ft~OD MANAGEMENT and the nonstructural floodplain policy objectives outlined in the early years of our The Flood Management Program is floodplain management program have never responsible for all programs and activities been fully realized. related to local flooding and the floodplain. The City of Boulder is extremely vulnerable to Current Program Elements flash flooding due to its geographical location at the base of the Rocky Mountains. Within the Current flood management program elements City of Boulder's 100-year floodplain there are include floodplain mapping, risk assessments, thousands of people and approximately 3,600 regulations, flood information and insurance, structures with an assessed valuation of almost emergency preparedness, property acquisition, $1 billion. and flood mitigation capital improvements. The City continues to grow through a Guiding Principles combination of new development and Using national and regional trends and redevelopment activity. Within the floodplain, philosophies, current and past local policies, these activities pose additional potential for and recommendations from the IRP and CRG hazards due to flash floods. as a backdrop for updating Boulder's flood management program, staff is recommending Recent projections indicate that almost 5 five guiding principles: percent of the parcels of land designated with redevelopment potential have greater than 50 1. "Preserve Floodplains." percent of their land area within the high hazard or conveyance flood zones. Current 2. "Be Prepared for Floods." City regulations would significantly restrict redevelopment of these parcels. Almost 20 3. "Help People Protect Themselves from percent of the parcels of land designated with Flood Hazards." redevelopment potential have greater than 50 percent of their land area within the 100-year 4. "Prevent Adverse Impacts and Unwise floodplain. Current City regulations do not Uses in the Floodplain." restrict redevelopment of these properties but require suitable flood protection measures. 5. "Seek to Accommodate Floods, Not However, these properties would still be Control Them." subject to flood damage from larger flood events. Many of these parcels are located in the Boulder Valley Regional Center and the downtown business area which will be impacted by Boulder Creek flooding. ES-2 cy\~e Flood d~a ~ City of Boulder ~ V ~ ~ c_ • Gf~~'fy Maste< Q~a~ Recommended Flood Management There has been a strong community interest in Program Elements offering a greater balance of non-structural flood management program activities as part Ftoodplain Mapping Studies Program of the overall Stormwater and Flood Management Utility program. These Floodplain mapping studies are essential in recommendations will serve to help achieve determining areas where life safety is this balance: threatened and damage to property is likely. ~ Create a flood management program A 10-year update cycle coincides with the resource center and program manager. City's average timeline for updating new citywide topographic, planimetric, and aerial ~ Allocate $125,000 annual funding and base mapping used for the study purposes. staff resources for program support. In-depth analysis of floodplain mapping results ~ Enhance the flood management Web site. can offer insights into the associated risks and levels of hazard inside the floodplain. The ~ Pursue an improved Community Rating expanded hazard information is valuable for System CRS} rating given available enhancing non-structural flood management resources. program activities supported by the community. ~ Research a local flood proofing program. Recommendations include: FloodPreparednesS ~ Adopt a 10-year update cycle for local The guiding principle to "be prepared for floodplain mapping studies. floods" focuses on floodplain emergency ~ Include floodplain risk assessments in all preparedness. Flood preparedness is a critical floodplain mapping updates. element in the City's floodplain management program, considering that more than 15 percent of the community is impacted by Public Education and Flood Insurance floodplains. The guiding principle to "help people protect The more prepared a community can be with themselves from flood hazards" focuses on pre-flood preparedness, ongoing monitoring, educating the public about flooding and effective warning systems, trained response, providing information and resources the public and post-flood recovery, the better chance the may access to reduce their own exposure to risks of flooding may be managed. flooding. Given that Boulder is nearing "build- out," this approach allows the flood Recommendations include: management program to reach out and benefit the community at large. ~ Enhance coordination between the Office of Emergency Management and the City of ES-3 cy\~e Flood d~a ~ City of Boulder ~ V ~ ~ . Gfi//fy Master P\a~ . Boulder by taking a more active role in ? Evaluate the adequacy of the ftvod emergency management. protection elevafivn for food proofed sfruct~res. ? Continue to enhance flood monitoring and prediction, early warning, and multiple ? Develop hazard analysis standards. notification measures by implementing the findings in the University of Colorado and ? Seek FEMA approval of engineered recent system evaluations. foundation standards for crawlspaces. ? Update and improve the flood response ? Research limited residential flood-proofing and flood recovery plans to address options for structures located in lower-risk actions by public officials and actions by shallow flooding areas. residents and members of the public. ? Develop innovative userfriendly ? Evaluate the Association of State information materials for the publ is and Floodplai n Managers "no adverse impact" residents to follow in the event of a flood. approach to floodplain management. ? Seek FEMA and UDFCD acceptance of the Floodplain Regula&ons City conveyance zone ~floodway}. Floodplain regulations are land use ? Seek Boulder County/City of Boulder regulations intended to regulate activities and regulatory consistency. development in the 100-yearfloodplain, conveyance zone ~or floodway}, and high hazard zone. They are designed to provide a PropertyAcqutsttlan and Floodptatn mechanism to address life safety and property !~l1r~Jr~atl0n damage impacts by restricting certain activities and improvements in the floodplain. The floodplain risk assessments will provide a more detailed framework for evaluating The floodplain regulatory revisions include floodplain management and/or mitigation recommendations intended to better address alternatives. issues of life safety and structural safety: The property acquisition and constructed flood ? Assess the adequacy of life safety mitigation program has been very successful measun~. over the years. However, modern community interests and national trends away from ? Address floodplain mapping uncertainties. structural drainageway construction have raised questions regarding previous structurally ? Develop options for mitigating new oriented projects that involve significant costs floodplain encroachments. and raise environmental and aesthetic issues. The following recommendations offer ? Develop 500-yearprofectiort sfctndards for approaches to balance structural and non- criticalfacilities. structural alternatives: ES-4 cy\~e Flood d~a ~ City of Boulder ~ V ~ ~ c_ • Gf~~'fy Maste< Q~a~ ~ Floodplain risk assessments, developed in permit compliance is based on implementation conjunction with floodplain mapping of stormwater management programs intended updates, should be used to identify and to reduce pollutant loading from urbanized quantify life safety and property damage areas. risks to determine appropriate measures for property acquisition and floodplain Water quality in Boulder Creek and its mitigation. tributaries is a significant concern. The CDPHE is considering listing Boulder Creek as an ~ A balance of constructed flood mitigation impaired water body for E. coli bacteria projects rbased on risks to life safety and of contamination. property damage} and acquisition of property r;including removal of associated Currently, Best Ntanagement Practices ~Btv1Ps} structures} should be applied to long-term identified as options in the City's Design and floodplain management and preservation. Construction Standards r;DCS} are geared more toward new development than toward re- ~ Non-structural alternatives shall be development. Boulder is predominantly "built- considered and balanced with structural out", and guidelines focused toward new measuresforfloodplain planning and development have limited applicability in mitigation activities. denser, redeveloping areas such as the Boulder Valley Regional Center and the downtown business center. Therefore, more STORMWATFR QUA~lTY innovative solutions need to be applied. Examples of these BMPs include porous The City's stormwater Quality Program is pavements, subsurface detention, vegetated responsible for managing local activities to landscape filters and hydrodynamic separator preserve, protect, and enhance water quality devices. affecting Boulder's streams and drainages. The current program has four main components: Current Program Elements ~ Public Education Current stormwater quality program elements ~ Water Quality Ntonitoring include water quality regulations, sub-basin management and stream enhancement. ~ Regulatory Compliance Guiding Principles ~ Source Control Recommended stormwater quality guiding In 2001, in response to Clean VdaterAct principles, based on national trends and requirements, Colorado Department of Public current local policies, include: Health and the Environment r;CDPHE} expanded its regulations to include regulations 1. "Preserve Our Streams" for discharges from municipal storm sewer 2. "Prevent Adverse Impacts from systems for cities with populations less than stormwater" 100,000 and more than 10,000. stormwater ES-5 cy\~e Flood d~a ~ City of Boulder ~ V ~ ~ Gfi//fy Master P\a~ . 3. "Protect and Enhance Our Stream ~ Enhance water quality monitoring program Corridors" to improve data analysis, program evaluation and compliance tracking. Recommended Stormwater Quality Sub-basin Management Program Elements Sub-basin management focuses on reducing Water Quality Regulafions the impact of runoff by focusing on preventive measures to minimize pollution at the source. Implementation of a common approach results Recommendations include: in consistency throughout the Boulder Creek watershed and provides more comprehensive, ~ Research BMPs oriented to redevelopment regional protection of water quality. and existing development in highly urbanized areas such as the Boulder Valley Continued water quality monitoring of the Regional Center and the downtown main stem of Boulder Creek will provide business center and incorporate information needed to evaluate the impact of appropriate BMPs into City Ordinances existing and new regulatory requirements such and Standards. as the Total Maximum Daily Limit ~TMDL} and sediment/aquatic life standards. ~ Integrate water quality objectives into the City master planning process, such as Recommendations include: updates to the Boulder Valley Comprehensive Plan ~BVCP} and the ~ Update City codes and development update to the Stormwater Management standards to meet applicable federal and Plan. state regulations. Update City standards to exceed federal and state requirements ? Examine the stormwater utility rate structure where appropriate to meet local water to promote innovative BMPs and quality protection needs. investment in public regional BMPs. ~ Ensure adequate funding for the continued ~ Develop incentive programs to promote participation in the WASH program and BMPs in both residential landscapes and the City's individual requirements for commercial development that are compliance with the City`s Stormwater innovative and exceed City requirements. Permit. ~ Explore the use of subsidies, public-private ~ Continue to pursue opportunities to partnerships, and grant-funding to collaborate with other communities to implement innovative urban BMPs. address water quality issues. Consider special improvement districts for targeted areas, such as the Boulder Valley ~ Track upcoming regulatory changes to Regional Center and downtown business develop the most cost effective approach center. to compliance. ES-6 cy\~e Flood d~a ~ City of Boulder ~ V ~ ~ c_ • Gf~~'fy Maste< Q~a~ ~ Increase the water quality benefits derived enhancement through the major from the City's urban forest through drainageway planning process. support of the City's Urban Forest Program and tree planting programs for parks and ~ Expand the Greenways Master Plan other City owned properties. Consider principals to all tributaries beyond Boulder updating regulations and standards to Creek and the six tributaries currently increase tree planting requirements for studied. new development and re-development projects. ~ Use balanced approaches to drainage solutions that provide multiple benefits, ~ Integrate multiple objectives including including the water quality/quantity water quality enhancement on City-owned benefits of preserving the stream corridor land and in decisions regarding future and its natural character. property acquisition. ~ Avoid hydrologic disconnect between ~ Develop GIS tool to prioritize water quality groundwater and surface water in stream improvement projects for sub-basins channels. using data such as potential pollutant loading, land-use, impervious surface, ~ Implement sub-basin water quality groundwater recharge and other data, management practices and projects in some of which has been developed in the conjunction with Greenways project 2000 Boulder Creek Watershed Study. implementation. ~ Update development and re-development ~ Update the Greenways Design Guidelines regulations and standards to expand runoff to include measures to stabilize channel reduction and water conservation erosion and sedimentation, support fish and other aquatic species movement, requirements. protect riparian habitat, and other measures to promote stream stability. Stream Enhancement Stream enhancement focuses on the stream STORMWATFR DRAINAGE corridor itself. Stable stream environments are necessary for fish and other aquatic species to The City's stormwater collection system consists survive. Riparian habitat provides a number of of a variety of storm sewers and open drainage water quality and ecosystem functions. ditches that collect water and divert the water to major drainageways. Recommendations include: Irrigation ditches collect stormwater in many Protect and preserve the watershed's most places in the City. Depending on the amount critical and fragile areas -floodplains. of rainfall, stormwater flows may exceed the Provide ample flood capacity and capacity of the ditch and spill from the ditch in freeboard, allowing for increase in riparian an uncontrolled manner. vegetation and roughness. Integrate floodplains protection with stream channel ES-7 cy\~e Flood d~a ~ City of Boulder ~ V ~ ~ In the past, the Utility's emphasis has been to residential areas and 5-yearfrequency for provide structural solutions, such as commercial/ industrial areas} drainage related drainageways and storm sewerfacilities, to Capital Improvement Projects (CIP}. This 20- resolve stormwater and flood management year old plan should be updated to include issues. Now, the overall guiding principles are drainage, detention, groundwater and in place to develop a balance of structural and stormwater quality issues. Land use has non-structural solutions to these critical changed significantly and the plan should programs and activities. consider planned development and redevelopment activities. stormwater quality permitting requirements and BMPs should be Current Program Elements further assessed and applied to individual sub- Current stormwater drainage program basins. The following issues should be elements include stormwater collection system considered: and planning; design and construction standards; maintenance; detention and ? Assess current and future land use and groundwater extraction and release. associated imperviousness. Guiding Principles ? Update hydrology/hydraulic models. Guiding principles for the stormwater drainage ? Consider groundwater flows when program component based on national trends evaluating existing capacity. and current local policies, are proposed as follows: ? Consider peak flows for the minor and major storm events. 1. Maintain and Preserve Existing and Natural Drainage Systems." ? Limit the post development peak discharge rate to the pre-development discharge rate 2. "Reduce and Manage Developed for single design two-year storm events. Runoff." ? Separate stormwater drainage from the 3. "Eliminate Drainage Problems and irrigation ditches. Nuisances." ? Focus on known problem and future development areas. Recommended stormwater Drainage ? Integrate water quality and other multi- program Elements objective issues in the updated plan. StormwaterCollection System and ? Re-evaluate detention including the Planning possibility of regional detention and increasing existing detention. The existing stormwater Collection System Master Plan provides the City of Boulder with a ? Locateestimate}the water table guide for minor storm ~2-year frequency for throughout the City. ES-8 cy\~e Flood d~a ~ City of Boulder ~ V ~ ~ c_ • Gf~~'fy Maste< Q~a~ ~ Re-evaluate remaining projects for ~ Remove debris from inlets on a 2-year necessity and community objectives. cycle or as needed based on requests. Re-prioritize recommended projects. ~ Remove silt and sand deposits from manholes and open channels on a 2-year ~ Review and revise the City's criteria for cycle or as needed based on requests. prioritization. ~ Inspect and repair storm sewer pipe on a Design and Construc&on Standards 2-year cycle or as needed based on requests. The City's Design and Construction Standards ~DCS} regulate the design and construction of ~ Clean excessive deposits of sediment public infrastructure, improvements, and within storm sewers on a 2-year cycle or as landscaping within the City's public rights-of- needed based on requests. way and public easements. The current standards were last updated November 16, Deters&on 2000, and need to be consistent with the most current versions of the Urban Drainage and The City has required on-site detention for new Flood Control District ~UDFCD} standards. developments since the early 1970s. On-site Stormwater drainage and stormwaterquality detention storage is required for all standards also need to be integrated. developments other than individual single- family lots that are not part of a larger Maintenance development. lvtost of these facilities are privately owned and maintained. The design of The recommended action items will address these facilities is reviewed by City staff at the the current maintenance issues of frequency time of application. The facilities are inspected and tracking of maintenance activities. and as-built drawings are now required to be submitted. However, there is currently no ~ Integrate above grade facility information follow-up City inspection to assure these associated with the major drainageways facilities are functioning as originally intended. into the City's maintenance management system. Recommendations for on-site detention include: ~ Integrate maintenance performed by the UDFCD into the City's maintenance ~ Review each development plan to look for management system. opportunities to increase detention greater than the minimum currently required. ~ Include project management personnel in the Call-Log database. ~ Integrate water quality B1vtPs into on-site detention requirements. ~ Inspect and remove excessive vegetation and debris along open drainageways on a ~ The amount of detention should be based yearly cycle or as needed based on on the degree of redevelopment proposed requests. ES-9 cy\~e Flood a~a ~ City of Boulder ~ V ~ ~ Gfi//fy Master P\a~ . or an incentive plan, where going above ~ If the City believes or knows of a problem and beyond decreases fees. area, then a mitigation plan should be required prior to permitting. Recommendations for existing detention facilities include: ~ If groundwater is not expected but is encountered during construction then a ~ Determine if additional inspection and mitigation plan should be required priorto maintenance is needed based on the issuing the certificate of occupancy. condition assessment of a random sampling of the existing facilities. On- ~ Evaluate the implications of groundwater going inspection and maintenance could contamination and further explore existing be accomplished by either the City or available soils information. private property owners. ~ Require property owners to periodically ~ Consider groundwater discharge as part of submit an inspection report to the City the update to the Sformwafer Co!lecfion once every 5 years to certify that the System Master Plan. detention facility is functioning as originally ~ Identify problem areas and issues including designed or there is a plan for the effect ofgroundwater de-watering on improvements. local waterwells and wetlands. Groundwater ~ Develop mitigation options for specific problem areas based on estimates of Groundwater and sump systems create additional groundwaterflow. nuisance drainage in the public rights-of-way and potential hazards due to build-up of slime and ice. Also, groundwater de-watering PROGRAM 1NTPGRATlON AND systems can affect local water wells and wetlands by lowering the groundwater table. IMPLEMENTATION OPPORTtINlT1FS Requirements for groundwater extraction and The Stormwater and Flood Ntanagement Utility release are loosely defined in current City is part of the City's Public Works Department. regulations. The organizational structure of the Department The recommended action items will allow fora provides both opportunities for and challenges proactive, rather than reactive, approach to to integrating various program interests and dealing with groundwater issues: other multi-objectives. Current Program Elements ~ Identify problem areas and require more precise water table information that The following institutional opportunities for considers seasonal fluctuations. integration are currently defined: ~ Annual Budget Process ES-10 cy\~e Flood a~a ~ City of Boulder ~ V ~ ~ c_ • Gf~~'fy Maste< Q~a~ ? Greenways Master Plan and Program ? Annual Budget Process ? Project Planning and Approval Process A significant opportunity for integration with (PPAP} other City objectives is the 2005 update to the Boulder Valley Comprehensive Plan. The ? Community and Environmental Assessment update process will provide an opportunity to Process ~CEAP} review land use and zoning designations from the perspective of flood hazard, water quality ? Design and Construction Standards ~DCS} and drainage issues. A Flood Management Program office will be Recommendations established to enhance and integrate various program functions and provide a more Program Integra&on focused point of contact for other staff and the public. This office will work closely with This master plan recommends maintaining Planning and Development Services - existing coordination and integration Floodplain and Wetland Management, which processes. In addition to these existing will continue to be the focal point for processes for program integration, this master interactions with the development community. plan has identified additional opportunities for coordination: In addition it is recommended that the Greenways program be expanded to all 15 of ? Board and Council Review and Discussion the City's major drainageways to provide for of CFS Utility Master Plan better integration of multiple objectives. ? Interactive Web Site These additional opportunities provide a way to integrate various program interests and ? Stormwater Management Plan other multi-objectives. ? Major Drainageway Planning Program Implementation ? Design and Construction Standards To assure integration with various program interests and other multi-objectives the City will ? Flood Management Program use amulti-disciplined approach and involve staff from appropriate workgroups. ? Greenways Program including update to Greenways Design Guidelines} ? Boulder Valley Comprehensive Plan FINANCIAL CONSID~RATlONS The Utility is an enterprise funded primarily by ? Water Quality Master Plan monthly utility fees. The Utility today receives annual revenues of over $4 million that are ? Maintenance Program applied to operating activities, emergency ES-11 cy\~e Flood a~a ~ City of Boulder ~ V ~ ~ c_ • Gf~~~fy Maste< Q~a~ preparedness, stormwater quality, stormwater plan considers evolving regulations, maintenance and capital improvements. technology and development characteristics. A slower, methodical approach will allow for In general, existing programs are adequately planning and adapting to these anticipated funded. However, several increases to existing changes. program funding are presented. To support these increases in funding, money will need to be reallocated from the existing budget or a rate increase will be required as follows. The following proposed financial plan will be considered as part of the City's on-going budget process. Flood Management It is proposed that annual funding forthe on- going flood management program increased from $100,000 to $350,000 peryear. This represents a shift to balance structural and non-structural solutions for flood management. stormwater Management It is proposed that: ~ A one-time additional funding allocation of $250,000 should be made in the 2005 budget to update the stormwater Collection System tvtaster Plan. ~ Additional annual funding of $50,000 should be allocated to begin an inspection and maintenance program for stormwater quality and existing private on-site detention facilities. ~ Additional annual funding of $50,000 should be allocated to GIS tools development and support. At proposed funding levels it will take many years to achieve the goals of this master plan. The financial approach recommended in this ES-12 ATTACHl1'IENT B STUDY SESSION OUTLINE MEMORANDUM TO: 11'Iayor and Members of City Council FROM: DATE: TBD SUBJECT: Study Session on Floodplain and Wetlands Policy and Regulation I. PURPOSE A. Introduce Council to the purpose and importance of protecting floodplains and wetlands; B. Provide Council with background on the Floodplain Ordinance and Wetlands Protection Ordinance; C. Get feedback from Council on floodplain and wetland policy issues and preliminary approaches for changing the wetlands ordinance. II. OVERVIEW A. Background on each regulation (BRIEF HISTORY AND INTENT OF EACH) B. Difference between the two regulations C. Local v. federal regulation (Why regulate locally?) III. QUESTIONS FOR COUNCIL: Floodplain A. Does Council have questions about current floodplain regulations and floodplain management work efforts? B. Does current Council agree with previous Council direction for staffto evaluate changes to floodplain regulations that will require higher regulatory standards for critical facilities? C. Which definition of "critical facilities" does Council recommend that staff further analyze? D. Does Council have any questions or suggestions regarding the proposed technical analysis and public process prior to bringing forward a new ordinance regarding flood regulation standards for critical facilities? Wetlands A. Does Council have questions or comments on the key issues with the Wetlands Protection Ordinance as previously identified by staff and Planning Board? Page 1 B. Does Council have questions or comments on the objectives of the project and the previous direction on revising the ordinance? C. Are the approaches to changing the ordinance the right approaches to further analyze? IV. FLOODPLAIN MANAGEMENT PROGAM A. Background 1. Boulder's floodplains and flood history 2. Boulder's floodplain regulations 3. Participation in the National Flood Insurance Program (NFIP) 4. Comprehensive Floodplain and Stormwater (CFS) IVlaster Plan B. Issues 1. Critical Facilities Standards a. Definition of Critical Facilities b. Number and Location of Critical Facilities c. Proposed Technical Analysis C. Next Steps 1. Proposed Public Process 2. Anticipated Schedule V. WETLAND PROTECTION PROGRAM A. Background 1. Intent, approach, and structure of Boulder's ordinance 2. Comprehensive Remapping Project a. Purpose and conclusions of project b. Issues raised during public process i. Examples 3. Buffer area study a. Purpose and scope b. Conclusions B. Issues 1. Overview of ordinance revision project a. Issues and objectives (as identified by Planning Board and City Council) b. Process 2. Discussion and analysis of approaches 3. Feedback from the public C. Next Steps 1. Decision-making flowchart and schedule Page 2 Page 3