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HomeMy WebLinkAboutComplete WRAB Packet 7-21-14 WATER RESOURCES ADVISORY BOARD MEETING MEETING DATE: Monday, 21 July 2014 MEETING TIME: 7:00 p.m. MEETING LOCATION: Yards Conference Room 5050 E. Pearl Agenda Highlights : 1.Call to Order (7:00 p.m.) 2.Approval of the 16 June Meeting Minutes (7:01 p.m.) 3.*Public Comment (7:05 p.m.) 4.Information Item – Overview of Floodplain Management Program and Floodplain Mapping Studies. (7:15 p.m.) 5.*Public hearing and Consideration of Motions to Recommend Adoption of Floodplain Mapping Revisions for Lower Bear Canyon Creed and Upper Boulder Slough. (7:40 p.m.) 6.Information Item – Update on South Boulder Creek Floodplain mitigation Study. (8:15 p.m.) 7.Matters (8:45 p.m.) a.From the Board b.From Staff 8.Future Schedule (8:55 p.m.) 9.Adjournment (9:00 p.m.) * Public Comment Item Information : Contact the WRAB Secretary, Kaaren Davis (303) 441-3233 or davisk@bouldercolorado.gov . Packets are available in the reference section of the Main Library and on-line at http://www.bouldercolorado.gov, Departments, Public Works, Agenda item times are approximate. Utilities, Water Resources Advisory Board. CITY OF BOULDER, COLORADO BOARDS AND COMMISSIONS MEETING MINUTES Name of Board / Commission: Water Resources Advisory Board Date of Meeting: 16 June 2014 Contact Information of Person Preparing Minutes: Kaaren Davis 303.441.3203 Board Members Present: Vicki Scharnhorst, Dan Johnson, Mark Squillace, Lesley Smith Board Members Absent: Ed Clancy Staff Present: Jeff Arthur, Director of Public Works for Utilities Bob Harberg, Principal Engineer - Utilities Cole Sigmon, Process Optimization Specialist Douglas Sullivan, Engineering Project Manager Chris Douville, Wastewater Treatment Manager Bret Linenfelser, Water Quality and Environmental Services Manager Tom Settle, Water Treatment Manager Ken Baird, Utilities Financial Manager Kaaren Davis, Board Secretary Meeting Type: Regular Agenda Item 1 – Call to Order [7:00 p.m.] Agenda Item 2 – Approval of the 24 February, 17 March and 21 April 2014 Meeting Minutes: [7:01 pm] 19 May minutes : Motion to approve minutes from May 19th as amended. Moved by: Johnson Seconded by: Squillace Vote: 4:0 Agenda Item 3 – Public Participation and Comment [7:03 p.m.] Public Comment: Cory Robinson: of Frasier Meadows. Experienced sewage overflow during flood. Neighbor informs him that that situation has occurred 4 times in 40 years. Money is hard to come by, but this is an ongoing emergency situation. Corrective action and money need to be applied sooner rather than later. Bill Hayes: of Frasier Meadows. Licensed professional engineer. Does have some knowledge of water control. Had his sewer line scoped and cleaned when he bought his house. The line backed up six days later. City Risk Management representative claimed that stormwater could not enter the sanitary sewer system. Demonstrated to her that she was in error. Have had sanitary sewer backup several times. 5.5 feet of sewage with flood event. This is an ongoing public health issue. Funding is available now with HUD and similar programs. Take advantage of it. Mallory Kates : Frasier meadows. Also had over 5 feet of sewage in her basement during the flood event. Has been to the WRAB meetings for several months now. Consultants give the impression that Council knows about the problem and that Council is listening carefully to the WRAB’s input. She spoke to a Council member recently who had no knowledge of the Frasier Meadows situation. The Council member said he could not stay on top of everything. This is a serious and urgent situation. He should be ashamed of himself. WRAB should be feeling foolish and taken advantage of. Not in the mood to play nice anymore. Board follow up: Agenda Item 4 – Public hearing and WRAB recommendation on the 2015-2020 Capital Improvements Program (CIP) [7:13 p.m.] Jeff Arthur, Ken Baird, Bob Harberg and Douglas Sullivan presented the item to the board which included a PowerPoint presentation. WRAB Minutes 16 June 2014 Page No. 1 Executive Summary from the Packet Materials: As part of the city’s annual budget process, the Utilities Division develops a six-year planning budget, this year for the time period of 2015 through 2020. Utilities staff has formulated revenue and expenditure projections for each of the three utility funds through the year 2020. Within the budget process, council approves and appropriates funds only for the first year, 2015. In order to better integrate data and public feedback related to the flood into the 2015-2020 CIP discussion, staff presented “previews” of the Water, Wastewater, and Stormwater/Flood Management Utility Capital Improvement Programs at the January, February, and March WRAB meetings. The April meeting provided an opportunity for the WRAB to discuss a “preliminary draft” of the CIP. WRAB members indicated general support for the preliminary CIP for both the Water and Stormwater/Flood funds, but requested that additional information regarding the wastewater collection system be provided at the May meeting. At the May 19 meeting, staff provided detailed information regarding the wastewater collection system condition assessment, newly identified corrosion issues in the city’s interceptor sewer, and a plan for system rehabilitation based on a 10% revenue increase in 2015 followed by 7% increases in both 2016 and 2017, and a 10% increase in 2018. The proposal maintained a competitive rate position for the city relative to other front range cities, but raised concerns from the public and some board members due to an approximately 45-year timeframe required to fully rehabilitate or replace aging vitrified clay and concrete pipes and the lack of immediate investment in projects identified in the 2009 Wastewater Collection System Master Plan. Board members expressed an interest in better understanding a level of investment that would appropriately address existing and future issues with infiltration, inflow, and structural integrity while avoiding unnecessary rehabilitation of pipes well ahead of the end of their useful lives. This memorandum includes both the wastewater collection system rehabilitation approach based on the revenue increase scenario presented in May and a new scenario that would target a 20 year planning horizon for system rehabilitation and expedite implementation of recommended master plan improvements. The new scenario would require a 25% revenue increase in 2015, but would allow for smaller increases in subsequent years than was proposed with the original 10% scenario. Staff is recommending that WRAB support the CIP proposal based on the 25% revenue increase scenario. This packet contains information concerning the Preliminary 2015 Utilities Budget and the 2015-2020 Attachment A Utilities CIP. contains Fund Financial and CIP spreadsheets for the Water, Wastewater, and Stormwater/Flood Management Funds and includes the 25% revenue increase scenario in the Wastewater Attachment B Fund. Similarly, contains Fund Financial and CIP spreadsheets for the three funds, but includes the 10% revenue increase scenario in the Wastewater Fund. Staff requests a recommendation from the WRAB concerning the 2015 Utilities Budget including the 6- year Capital Improvement Program (CIP) and Monthly Utility Rates. Staff will submit the CIP to the Planning Board which will make a recommendation to City Council on July 31. City Council study sessions are scheduled for August 12, 2014 concerning the proposed city-wide 2015-2020 CIP and on September 9 and September 23 on the recommended 2015 city-wide budget. Public Comment: Patricia Multhaaf : Frasier Meadows. Encourage the WRAB to speed up the process. People in the neighborhood have been suffering for years due to lack of maintenance, etc. Serious damage has been done. Understands that Boulder Creek is an issue, but what happened in Frasier Meadows was due to lack of maintenance, not flooding in Boulder Creek. In a city like Boulder which emphasizes infrastructure for Bike Paths, Open Space etc, due consideration needs to be given to maintenance of the existing systems. Roger Kaenig: University- Gregory Creek Improvement Organization. Use of CIP funds that have been gained from his community’s participation. Community meeting Thursday said hire C2HMHill for study, but no plan to file for map revision which is key step to seek funding from FEMA, urban flood control district and other similar organizations. Urge WRAB to provide guidance to staff and Council to have a new study done and use funds appropriately for re- mapping. Carl Norby (Using pooled time from Cam Oetting and Robert Pressey Techapps): Funding has been intensively discussed since the flood event. The WRAB has expressed a preference to stay in the middle range of the Front Range city rates. For a community having the number one flood rate risk, it seems that perhaps middle of the pack funding is not the best plan. A better way to do it is to assess the need, rather than the comfort of the Board. On a different topic, most of the flooding in his neighborhood was from Bear Creek around land owned by CU. Have any of the board members walked this area? If anyone had they would understand what the public has been WRAB Minutes 16 June 2014 Page No. 2 talking about. It is a disaster waiting to happen. Water was 5.5 feet deep in the underpass under US 36. The Bear Creek is not that deep. Greenways department loves trees in the stream at low flow. Not good sense for flood mitigation. Mallory Kates: We all know the problems we are talking about have existed for decades. There have been other well intentioned people hearing this. Is there any historical evidence that Council listens to the WRAB or its consultants. Council is not listening. Neighbors must get together to make Council listen. Must get more aggressive with Council WRAB Discussion Included: Discussion indicating that the WRAB found the prioritization of the CIP to be sound. Discussion regarding timelines and costs associated with specific projects such as: Sanitary Sewer Line Rehabilitation, Carter Lake Pipeline, Lakewood Pipeline. Discussion of the proposed commercial rate increases including discussion of stakeholder outreach which has been done. General discussion on rate increases, including the information that the proposed increases are projected to be adequate to address essential projects (such as sanitary sewerline rehabilitation and replacement) in a much shorter time frame than would previously have been possible. Flood repair and recovery issues were discussed. Including: costs for flood repairs, funding strategies and redistributions to meet those costs, and potential for recovery of funds from FEMA. Prioritization of work on major drainageways was also discussed. Discussion on annexation related water system expansion. Discussion on the need for continued community outreach and cycling of information back to the WRAB during the rate increase proposal process. Motion: The Water Resources Advisory Board recommends approval of the 2015-2020 CIP for the Water, Wastewater, and Stormwater/Flood Management Utilities proposed in Attachment A including proposed rate adjustments to support 2015 revenue increases of 5% in the water utility, 25% in the wastewater utility, and 71% in the stormwater and flood control utility. Motion by: Squillace, Seconded by: Johnson Vote: 4-0 Motion Passes Agenda Item 5 – Matters [8:38 p.m.] From the Board: Board member Smith brought up: Pilot intern program to bring college students in to help with research. Took tours of City facilities with students. Staff did a great job answering student questions. From Staff: [8:40 p.m.] None Agenda Item 6 – Discussion on Future Schedule [8:40 p.m.] Next three meetings are flood study. July or August, South Boulder Creek Mitigation Study. July- Bear Canyon Creek, Harrison Avenue Levy and Boulder Slough. August- Twomile, Upper Goose Creek, Skunk, Bluebell and King’s Gulch. Agenda Item 7 – Adjournment [8:50 p.m.] There being no further business to come before the Board at this time, by motion regularly adopted, the meeting was adjourned at 8:50 p.m. Motion to adjourn by: Squillace; Seconded by: Smith Motion Passes 4:0 Date, Time, and Location of Next Meeting: The next WRAB meeting will be Monday, 21 July 2014 at 7:00 p.m., in the Municipal Service Center Conference Room; 5050 E. Pearl unless directed by staff or the board. APPROVED BY: ATTESTED BY: _________________________________ ___________________________________ Board Chair Board Secretary _________________________________ ___________________________________ WRAB Minutes 16 June 2014 Page No. 3 Date Date An audio recording of the full meeting for which these minutes are a summary, is available on the Water Resources Advisory Board web page. WRAB Minutes 16 June 2014 Page No. 4 C I T Y O F B O U L D E R FLOODPLAIN MANAGEMENT PROGRAM Introduction The City of Boulder has a significant flood risk, primarily due to its location at the mouth of Boulder Canyon and other canyon creeks. The city has a long history of flooding and has developed a comprehensive floodplain management program designed to identify and mitigate the risks of flooding, minimize loss of life and property damage, and support recovery following a major flood event. Major components of the city’s floodplain management program include mapping, mitigation master planning and construction, property acquisition and flood protection through land use regulations and flood preparedness. This document provides a brief summary of each of the city’s floodplain management program elements along with a summary of the National Flood Insurance Program. Flood Risks Figure 1 The City of Boulder has 15 major drainageways (). Approximately 13 percent of the city is Figure 2 located within the regulatory 100-year floodplain (). Nearly 2,600 individual structures are located within this flood zone. Figure 1: Major Drainageways Agenda IV page 1 Figure 2: 100-Year Floodplain The greatest flash flood risk is generally considered to be between April 15 and Sept. 15, but flooding can occur at any time. Flooding can happen from both long duration and short duration storm events. Flash floods along the city’s creeks can occur very quickly with little or no warning. The greatest threat is from thunderstorms that produce high intensity rainfall in short periods of time. The city has had several flood events in the past. The largest flood on record hit Boulder Creek in 1894, greatly impacting the downtown area. Up to six inches of rain fell west of the city, resulting in 100-year event flows in Boulder Creek, extensive flooding up to one mile wide and the loss of one life. Boulder Creek flooded again in both 1914 and 1929. South Boulder Creek flooded in 1938 and again in 1969, causing extensive damage in Eldorado Springs and within the city limits. In 1906 Sunshine Creek Agenda IV page 2 experienced flash flooding and in 1909 a flash flood on Twomile Canyon Creek resulted in two deaths. More recently, a flash flood event in 2007 along Bear Canyon Creek resulted in roadway overtopping at Table Mesa Drive. Fourmile Canyon Creek overtopped its banks in the summer of 2011, producing minor flooding within the city and greater flooding upstream in Boulder County. In September 2013, the city experienced widespread flooding from a long duration storm event that produced up to 19 inches of rain over an 8 day period. Private properties and public infrastructure were damaged by this storm event in a variety of ways including impacts from localized drainage, ground water and wastewater collection system back-ups. The floodplain management program focuses mitigation efforts on flooding of the major drainageways. The timeline below outlines major events that have impacted the city’s floodplain management program. Agenda IV page 3 Wildfires Wildfires can increase flooding risks. The intense heat from a fire destroys vegetation and decreases the permeability of soils, resulting in increased runoff from burn areas. On Sept. 6, 2010, a wildfire started that eventually burned nearly 6,200 acres of the steep, forested Fourmile Canyon area just west of Boulder. Approximately 60 percent of the area was severely or moderately burned. Approximately 80 percent of the burn area is tributary to Fourmile Creek, which is a tributary to Boulder Creek (approximately two miles west of Boulder). Approximately 20 percent of the burn area is located in the Fourmile Canyon Creek watershed. Fourmile Canyon Creek flows through north Boulder and is also tributary to Boulder Creek, with a confluence downstream of the Boulder city limits. As a result of the burn, new hydrologic models were developed for the burn area. These models were calibrated and adjusted over time based on changing vegetation levels and observed runoff from rainfall events. Flood Emergency Preparedness Flood preparedness is a critical element in the city’s floodplain management program. The more prepared the community can be with pre-flood readiness, ongoing monitoring, effective warning systems, trained response, and post-flood recovery, the better chance the impacts of flooding may be managed. During the peak flood season, the Urban Drainage and Flood Control District (UDFCD) contracts to have 24-hour meteorologist coverage for the Denver metro area. The UDFCD meteorologists forward daily forecasts to the city and the Boulder Office of Emergency Management (Boulder OEM). The UDFCD also operates and maintains a network of stream and rainfall gauges in and around the city. This information provides real-time data that is monitored by the Boulder OEM during the flood season. Due to the very short time frame in which flooding can occur, there is often limited time available to provide adequate warning or to react. This is particularly true for some of the city’s smaller creek systems, which lack stream gauges. In addition, thunderstorm cells can move and intensify very rapidly and often unpredictably. It is therefore critical that people that live and work within these floodplains be aware of the risk, monitor the weather and prepare an emergency plan in advance. Flood education, regulations and ordinances are therefore critical components of the city’s flood emergency preparedness program. Floodplain Mapping Floodplain mapping provides the basis for flood management by identifying the areas subject to the greatest risk of flooding. This information is essential for determining areas where life safety is threatened and property damage is likely and is the basis for floodplain regulations and the National Flood Insurance Program. The city’s floodplain maps need to be periodically updated to reflect changes in the floodplain resulting from land development, flood mitigation improvements, new survey information and new study technologies. The city delineates four flood zones: Agenda IV page 4 500-year floodplain : delineates the flood limits resulting from a design storm that has a 0.2 percent chance of occurring in any given year. 100-year floodplain : defined as all land areas subject to inundation by flood waters in a design storm event having a one percent chance of being equaled or exceed in any given year. Conveyance zone : represents a preservation zone for passing flood flows along the creek corridor without increasing flood depths, redirecting flood waters or adversely impacting land areas. The establishment of a conveyance zone recognizes that development activities are expected to occur in the 100-year floodplain, but places a limit on these activities to prevent adverse impacts to the floodplain. High hazard zone : This area of the floodplain is where there is the greatest risk of loss of life. The area should not be occupied by people during a flooding event. The high hazard zone represents those areas in the 100-year floodplain where an unacceptably high hazard to human safety exists and where there is the potential for flood waters to sweep people off of their feet and wash them downstream. Research was conducted to determine the flood depths and velocities that were most likely to sweep people off of their feet. As a result of the research, the high hazard zone is defined as all areas in the floodplain where the flood water velocity (feet per second) multiplied by the flood water depth (measured in feet) would equal or exceed four or where flood water depth alone would equal or exceed four feet. An example would be a flood depth of three feet with the water only moving 1½ feet per second, which would result in a product number of 4½, thus placing the area within the high hazard zone. Figure 3 The components of the 100-year floodplain are illustrated in . Figure 3: Components of the 100-Year Floodplain Agenda IV page 5 The flood flows used in floodplain mapping studies come from hydrologic analyses using FEMA, Colorado Water Conservation Board and Urban Drainage and Flood Control District procedures and parameters. Peak flows are computed for each drainageway. Watershed characteristics such as size, shape, topography, vegetation, amount of pavement and impervious surfaces and soils characteristics are used to compute the flood hydrographs for various design points in the basin. The design storm used in the hydrologic analysis is typically a short duration (1 or 2 hour) storm. Rainfall intensities, used to calculate the peak flows for flood mapping, come from the UDFCD Drainage Criteria Manual and range from 2.4 to 2.7 inches per hour for the 100-year event. This design storm emulates a flash flooding event which is quite different from the long duration, less intense storm that led to the flooding in September. This diagram shows a comparison of a flash flood event with a longer duration, lower intensity storm event. In both events, 3.1 inches of rain fell, but the shorter duration and higher intensity storm produced a much higher peak flow (90cfs vs. 30cfs). Flood Mitigation and Property Acquisitions The city has been working for many years to reduce the flood threat by implementing major drainageway flood mitigation projects. In 1973, the city established a separate Stormwater and Flood Management Utility to provide a consistent, long term source of funding for these efforts. Flood mitigation master planning is typically scheduled to follow flood mapping updates. A flood mitigation plan identifies and evaluates the benefits and costs of potential improvement projects. Feasible projects from the plan are then programmed into the Capital Improvement Program (CIP) for design and construction. During the design phase, project alternatives are typically evaluated in a Community and Environmental Assessment Process (CEAP). Once a project is constructed, a Letter of Map Revision (LOMR) is completed and submitted to FEMA to update the flood mapping to reflect the improvements. Mitigation MappingCIPCEAPLOMR Planning A schedule for the current and recently completed floodplain mapping, mitigation planning and capital improvements can be found at: Agenda IV page 6 Flood Mapping, Mitigation Planning and CIP Schedule The flood mapping, mitigation planning and construction process takes years to complete due to its controversial nature and the extensive public process. As an example, the South Boulder Creek mapping study was initiated in 2002 and completed in 2007. The mitigation planning effort for this drainageway was initiated in 2009 and is still being evaluated. The design and construction of improvement projects also is a multi-year process. The Elmer’s Twomile Capital Improvement Project was initiated in 2001and completed in 2010. Given the long implementation phase, it is important to complete mapping studies prior to moving forward with mitigation projects in order to document the risk of flooding and make property owners aware of the risk. In addition to funding the construction of flood mitigation projects, the Stormwater and Flood Management Utility Capital Improvement Program allocates $500,000 each year for property acquisition. This provides funds for the purchase of properties in areas prone to flooding, especially in the city's high hazard regulatory area. High risk properties have been identified and prioritized for purchase along each of the city's major drainageways. This program has been “opportunity based,” working with willing sellers and relying on properties that become available on the real estate market. Floodplain Regulations Floodplain regulations are land use regulations intended to reduce risks to people and property in areas along rivers and streams that are prone to flooding. The City of Boulder adopted its first floodplain regulations in 1969, in response to flooding along the Front Range of Colorado. The city’s “Floodplain Regulations” are contained in Chapter 9-3, Boulder Revised Code (B.R.C.) 1981. Regulated flood areas are : 500-year floodplain 100-year floodplain Conveyance zone High hazard zone 500-year floodplain In 2014, new floodplain regulations were enacted to provide flood protection to critical facilities, such as hospitals, police stations, day care facilities and utility treatment facilities in the 500-year floodplain. 100-year floodplain A floodplain development permit is required for all development activities in the 100-year floodplain. Development within the 100-year floodplain is permitted, subject to the provision of flood protection measures to mitigate the risk of property loss or damage. In residential applications, this requires that the lowest floor of any new structure or addition be elevated above the flood protection elevation (which is two feet above the flood elevation). Basements are not permitted for residential structures. In non-residential applications, the lowest floor of any new structure or addition must be elevated above the flood protection elevation or be flood proofed to ensure that the structure is watertight with walls substantially impermeable to the passage of flood waters below the protection elevation. Floodproofing of structures must be provided in an automatic manner and not require any human intervention to be effective. This is often accomplished through the use of flood gates that will automatically raise during Agenda IV page 7 a flooding event, such as the flood gates at the Municipal Building, the St. Julien Hotel or Alfalfa’s Market. New structures in the 100-year floodplain are required to install protection against sewer back-ups that are likely to occur if the sanitary sewer system becomes surcharged during flood conditions. New parking lots are not permitted in the 100-year floodplain where flood depths would exceed 18 inches, since automobiles are buoyant and become flood debris at these depths. Hazardous materials may not be stored below the flood protection elevation (except for existing gasoline storage tanks that were in place prior to 1989). Mobile homes placed after July 1, 1989, must be elevated on a permanent foundation, and new structures are to be oriented to minimize flood flow obstruction. Conveyance zone The Conveyance zone represents a preservation zone for passing flood flows along the creek corridor without increasing flood depths, redirecting flood waters or adversely impacting land areas. The establishment of a conveyance zone recognizes that development activities are expected to occur in the 100-year floodplain, but places a limit on these activities to prevent adverse impacts to the floodplain. Development in the conveyance zone typically requires an analysis to ensure that flooding conditions are not worsened. Flood mitigation measures are sometimes required to offset the development and keep the floodplain from expanding or floodwaters from getting deeper. Regulations for the 100-year floodplain also apply to the conveyance zone. If an area is located in both the conveyance zone and the high hazard zone, all regulations apply. High hazard zone Development in the high hazard zone is most restricted due to life safety concerns. No new structures or additions to existing structures intended for human occupancy are permitted in the high hazard zone. It is anticipated that many structures within the high hazard zone will require evacuation during a major flooding event due to structural failure or potential issues with fire, sanitation, electric hazards, broken utilities, or debris. Additionally, no new parking lots and no change of use of an existing non-residential structure to a residential use is permitted. Regulations for the 100-year floodplain also apply to the high hazard zone and conveyance zone. Flood Insurance and the Community Rating System (CRS) The City of Boulder participates in the National Flood Insurance Program (NFIP) by adopting and enforcing floodplain management ordinances to reduce future flood damage. In exchange, the NFIP makes Federal government-backed flood insurance available to homeowners, renters and business owners, whether or not their properties are in a floodplain. Flood insurance covers direct losses caused by surface flooding, including a river overflowing its banks, a lake or ocean storm, and local drainage problems. The NFIP insures buildings with two types of coverage: structural and contents. Structural coverage is for the walls, floors, insulation, furnace, and other items permanently attached to the structure. There is a mandatory flood insurance purchase requirement that applies to all forms of federal or federally-related mortgages for buildings located in the 100-year floodplain. The maximum amount available for a single-family house is $250,000. While not mandated by law, a lender may also require a flood insurance policy as a condition of a loan for a property in any zone on a Flood Insurance Rate Map. The NFIP’s Community Rating System (CRS) is a voluntary incentive program that recognizes and encourages community floodplain management activities that exceed the minimum NFIP requirements. Agenda IV page 8 As a result, flood insurance premium rates are discounted to reflect the reduced flood risk resulting from community actions that meet the three goals of the CRS: 1.Reduce flood losses; 2.Facilitate accurate insurance rating; and 3.Promote the awareness of flood insurance. For CRS participating communities, flood insurance premium rates are discounted in increments of five percent; i.e., a Class 9 community would receive a five percent premium discount, while a Class 8 community would receive a 10 percent discount. The city joined the CRS in 1992 as a Class 8 community, improved to a Class 7 in 2008 and a Class 6 in 2012. The city was awarded a Class 5 in early 2013. As a result, standard policy holders now receive a 25 percent discount on flood insurance with anticipated city-wide annual savings of over half a million dollars. As of January 31, 2014, there were 3,830 policies held by City of Boulder residents, with a total insured coverage of $857,163,100 at a total premium cost of $2,909,611. Flood Recovery Flood recovery efforts have become a significant component of the city’s floodplain management program. The September 2013 flood resulted in sediment and debris in all 15 drainageways, bank erosion and damages to creek infrastructure including drop structures, trash racks, culverts and retaining walls. In addition to the restoration efforts, the flood recovery work also includes: documenting damages and flood extent information, assisting property owners, analyzing rainfall information, and coordinating with the State of Colorado and the Federal Emergency Management Agency. Flood recovery work is expected to continue through 2014 with follow-up documentation and audits for an additional 2 years. Flood Outreach The City reaches out to community members in a variety of ways to raise awareness of the risk of flooding and provides resources to help them prepare for a flood. Flood safety information is distributed to every school in the Boulder Valley School District to be sent home with every student. Flood safety class room programs are offered to all elementary school teachers and information is provided to th families of 5 grade students who participate in the annual Water Festival. Annual direct mailings to all properties located in the 100-year floodplain are coordinated through the Urban Drainage and Flood Control District. Flood awareness door hangers are distributed to off-campus housing neighborhoods and high-hazard residential properties. Information is distributed via local media both through press releases and paid advertisements. A utility bill insert is provided annually to 26,000 customers. Outdoor emergency sirens are tested monthly during the peak flood season. Since the September 2013 flood, the city conducted seven open houses to share information, help individuals recover and help us understand more about what happened during the event. Prior to the start of the 2014 flood season, two community preparedness open houses were held, which were attended by approximately 150 people. The City’s website includes extensive flood information at https://bouldercolorado.gov/flood including a newly created Community Guide to Flood Safety. Agenda IV page 9 C I T Y O F B O U L D E R WATER RESOURCES ADVISORY BOARD AGENDA ITEM MEETING DATE: July 21, 2014 AGENDA TITLE: Public hearing and consideration of recommendations to City Council to adopt the Lower Bear Creek and Upper Boulder Slough floodplain mapping revisions. PRESENTER/S: Jeff Arthur, Director of Public Works for Utilities Bob Harberg, Principal Engineer - Utilities Annie Noble, Flood and Greenways Engineering Coordinator Katie Knapp, Engineering Project Manager EXECUTIVE SUMMARY: The city has a comprehensive floodplain management program designed to identify flood risks, mitigate the risks of flooding, minimize loss of life and property damage and support recovery following a major flood event. Floodplain mapping provides the basis for the city’s floodplain management program by identifying the areas at the highest risk for flooding. Changes in land use, updated topographic mapping and upgrades to hydrologic and hydraulic models warrant periodic mapping updates. This memorandum presents two proposed floodplain mapping revisions: Lower Bear Canyon Creek The Lower Bear Canyon Creek study area extends from the confluence of Bear Canyon Creek and Boulder Creek (downstream) to Foothills Parkway (upstream) as shown on the map below. The study includes the data and documentation required for accreditation of the Harrison Levee. The Harrison Levee is provisionally accredited on the current Flood Insurance Rate Maps. This study also incorporates the updated hydraulic model for Boulder Creek at the downstream tie-in location and the additional culverts below Arapahoe Avenue that were installed to increase the conveyance of Bear Canyon Creek. Upper Boulder Slough The Boulder Slough study will update the hydraulic models and flood hazard mapping thth for the reach of Boulder Slough from 30 Street to 18 Street, including two split flow th paths north of the Slough, west of 26 Street. The study limits are shown on the map below. Modeling and mapping of this reach, as well as the split flow paths, utilize 2013 th LiDAR-based topographic data. The Boulder Slough downstream (east) of 30 Street will be studied as a separate effort after the completion of the improvements that are currently under construction. 1AGENDA ITEM #___V____PAGE____1____ Lower Bear Canyon Creek Study Limits 2AGENDA ITEM #___V____PAGE____2____ Upper Boulder Slough Study Limits The proposed mapping for both floodplains would result in a net decrease of 9 structures in the 100-year floodplain, a net increase of 11 structures in the conveyance zone and a net increase of 2 structures in the high hazard zone. Following input from WRAB, the mapping study will be considered by the City Council for approval to submit to FEMA and adoption for city regulatory purposes. The WRAB acceptance of the study does not require board members to verify the analysis and calculations, but indicates the overall study process and results are reasonable and acceptable. STAFF RECOMMENDATION: Staff requests Water Resources Advisory Board consideration of this matter and action in the form of the following motions: Motion to recommend that City Council adopt the Lower Bear Canyon Creek floodplain mapping revision. Motion to recommend that City Council adopt the Upper Boulder Slough floodplain mapping revision. COUNCIL FILTER IMPACTS: Economic: Flood insurance is required for properties located in the 100-year floodplain if they are financed by a federally-backed mortgage. Flood insurance 3AGENDA ITEM #___V____PAGE____3____ rates are set by FEMA based on the flood risk as shown on the flood insurance rate maps. Accurate floodplain mapping helps facilitate accurate flood insurance rates. The average annual rate for flood insurance within the city in 2013 was $760 (3,830 policies). Flood protection land use regulations also create costs for the property owners in the form of permit fees, increased costs of remodeling and restrictions on development. Flood insurance and land use regulations do, however, provide protection from potentially catastrophic losses due to floods. Environmental: Flood events can result in damage or destruction to buildings and corresponding release of man-made contaminants. Flood waters can also cause erosion and damage to areas of the natural environment that are not capable of conveying high-velocity stormwater. The updated mapping will more accurately identify the areas with the greatest flooding risks. Social: Floodplain mapping provides the basis for flood management by identifying the areas subject to flooding. This information is essential for determining areas where life safety is threatened and property damage is likely. Land use regulations help reduce risks to people and property in these high flood- risk areas. Accurate mapping of flood risks also helps implement effective flood preparedness and response programs, thereby increasing the safety of people living, working or visiting the City of Boulder. OTHER IMPACTS: Fiscal: Funding for this study is included in the Department of Public Works Utilities Division budget. Staff Time: Time for completing the study is included in existing work plans. BOARD AND COMMISSION FEEDBACK: The Bear Canyon Creek and Boulder Slough mapping Revisions have not been brought to any Boards or Commissions prior to WRAB. Following input from WRAB, the mapping revisions will be presented to City Council. PUBLIC FEEDBACK: Open house meetings were held in early July 2014 to inform the public about the mapping revisions. Most questions and concerns were about flood insurance requirements and plans for future drainageway improvements. BACKGROUND: The risk of flash flooding is an important issue for the City of Boulder primarily due to its location at the mouth of Boulder Canyon and other canyon creeks. Approximately 13 percent of the city is located within the 100-year floodplains of Boulder Creek and its 14 tributaries. Nearly 2,600 individual structures are located within this flood zone. Additional information about the city’s floodplain management program, floodplain Floodplain Management Overview. regulations and flood insurance can be found at: 4AGENDA ITEM #___V____PAGE____4____ Floodplain mapping provides the basis for the city’s floodplain management program by identifying the areas at the greatest risk for flooding.Changes in land use, updated topographic mapping and upgrades to hydrologic and hydraulic models warrant periodic mapping updates. The city has recently updated or is in the process of updating all of the floodplain mapping. Current mapping studies include Upper Goose Creek and Twomile Canyon Creek, Skunk Creek, Kings Gulch and Bluebell Canyon Creek. The city delineates four flood zones: 500-year floodplain: The 500-year floodplain delineates the flood limits resulting from a storm that has a 0.2 percent chance of occurring in any given year. 100-year floodplain: The 100-year floodplain delineates the flood limits resulting from a storm that has a one percent chance of occurring in any given year (26 percent chance over a 30-year mortgage). Conveyance zone: The conveyance zone is defined as the areas in the floodplain that are reserved for the main passage of the entire 100-year flood flow when the 100-year floodplain is artificially narrowed until a maximum six-inch increase in flood water depth is created. This zone is delineated to allow development to occur up to the narrowed floodplain and still provide passage of 100-year storm flows. High hazard zone: The high hazard zone defines the area of the floodplain where water depth and velocity pose a threat to life and safety. This area is delineated for areas in the floodplain where water depths are four feet or greater or where the water velocity multiplied by water depth equals or exceeds the number four. ANALYSIS: A Letter of Map Revision (LOMR) updates floodplain mapping and hydraulic models. There are two LOMR requests currently under consideration: Lower Bear Canyon Creek This LOMR request is being made to update a short reach of the Bear Canyon Creek floodplain. A LOMR is required to formalize flood mitigation improvements and to update hydraulic models. The hydrology used in the mapping update is from the 2012 FEMA Flood Insurance Study and is based on a 1-hour storm event. The City previously submitted a LOMR for Bear Canyon Creek from Foothills Parkway (downstream) to the city limits (upstream) to reflect changes authorized by City floodplain permits and update hydraulic models based on better, more detailed topographic information. This LOMR was submitted to FEMA in 2002 and approved on February 27, 2003. The study area for the current LOMR addresses the remainder of Bear Canyon Creek within the City limits, extending from the confluence of Bear Canyon Creek and Boulder Creek (downstream) to Foothills Parkway(upstream). This study includes the data and documentation required for accreditation of the Harrison Levee. The Harrison Levee is provisionally accredited on the current Flood Insurance Rate Maps. The LOMR will also incorporate the updated hydraulic model for Boulder Creek at the downstream tie-in location and incorporate the additional culverts below Arapahoe Avenue that were installed to increase the conveyance of Bear Canyon Creek. 5AGENDA ITEM #___V____PAGE____5____ Upper Boulder Slough th This LOMR updates a reach of the Boulder Slough floodplain from 30 Street th (downstream) to 18 Street (upstream). In 2013, the city completed a floodplain study for Boulder Creek to reflect changes authorized by city floodplain permits and update hydraulic models based on better, more detailed topographic information. The Boulder Creek floodplain study did not include the flow path for the Boulder Slough. The Boulder Creek study was submitted to FEMA in September of 2013 and is currently going through the Physical Map Revision (PMR) process. The Boulder Slough LOMR study will update the hydraulic models and flood hazard mapping for the 100-year flood, conveyance zone and high hazard zone for the reach of thth Boulder Slough from 30 Street to 18 Street, including two split flow paths north of the th Slough, west of 26 Street. Modeling and mapping of this reach, as well as the split flow paths, utilizes 2013 LiDAR-based topographic data. The Boulder Slough downstream th (east) of 30 Street will be updated as a separate effort after the completion of the improvements that are currently under construction. Results Attachments A through G present figures showing a comparison between existing and proposed floodplain mapping. A summary of how these changes impact existing Attachment H structures is included in . NEXT STEPS: Following input from WRAB, the mapping revisions will be considered by City Council. If City Council approves the map revisions, the city will submit the LOMR requests to FEMA for review. During the FEMA review and approval process it is recommended that the new mapping be used for regulatory purposes by regulating to the more restrictive of the existing and new mapping. This would mean that development within the newly identified flood zones would be subject to the city floodplain regulations. In order to comply with FEMA requirements, development within the areas that are being removed from the floodplain would still be subject to the city’s floodplain regulations until FEMA officially adopts the new floodplain mapping. Following formal adoption by FEMA, the city would regulate solely based on the new mapping. ATTACHMENTS: A.Bear Canyon Creek: Existing and Proposed 100-Year Floodplain B.Bear Canyon Creek: Existing and Proposed Conveyance Zone C.Bear Canyon Creek: Existing and Proposed High Hazard Zone D.Bear Canyon Creek: Existing and Proposed 500-Year Floodplain E.Boulder Slough: Existing and Proposed 100-Year Floodplain F.Boulder Slough: Existing and Proposed Conveyance Zone G.Boulder Slough: Existing and Proposed High Hazard Zone H.Summary of Impacts to Existing Structures 6AGENDA ITEM #___V____PAGE____6____ Attachment A DRY CREEK NO.2 Lee Cr Dallas Pl Legend Proposed Bear Canyon Creek 100 Year Floodplain Effective Bear Canyon Creek 100 Year Floodplain Effective Other Creeks 100 Year Floodplain Revised Boulder Creek 100 Year Floodplain Buildings Added to the 100 Year Floodplain (12) Buildings Remaining in the 100 Year Floodplain (27) Buildings Removed from the 100 Year Floodplain (37) Levee Creek Ditch City Limits Buildings Previously Removedfrom 100 Year Floodplain by LOMA for FEMA Flood Insurance Purposes Bear Canyon Creek 01252505007501,000Feet Proposed 100-Yr Floodplain 1:4,000 Compared to FEMA Effective The information depicted on this map is provided as graphical representation only. The City of Boulder provides no warranty, expressed or implied, as to the accuracy and/or completeness of the information contained hereon. Utilities Division © 2014 City of Boulder, CO Subject to Revision - Revised: 7/8/2014 Attachment B DRY CREEK NO.2 Lee Cr Dallas Pl The Conveyance Zone is a preservation zone for passing flood flows along the creek corridor without increasing flood depths, redirecting flood waters or adversely impacting land areas. The Conveyance Zone specifically includes the area of the floodplain which would be required for the passage (or conveyance) of the entire flood flow resulting from the encroachment (filling in or blocking out) of the 100-year floodplain from the edges until a maximum six-inch (0.5-feet) increase in flood water depths is created. Legend Effective Bear Creek Conveyance Zone Proposed Bear Creek Conveyance Zone Effective Other Creeks Conveyance Zone Revised Boulder Creek Conveyance Zone Proposed Skunk Creek Conveyance Zone Levee Creek Ditch City Limits Bear Canyon Creek 01252505007501,000Feet Proposed Conveyance Zone 1:4,000 Compared to FEMA Effective The information depicted on this map is provided as graphical representation only. The City of Boulder provides no warranty, expressed or implied, as to the accuracy and/or completeness of the information contained hereon. Utilities Division © 2014 City of Boulder, CO Subject to Revision - Revised: 7/9/2014 Attachment C DRY CREEK NO.2 Lee Cr Dallas Pl The High Hazard Zone is the area of the floodplain where there is the greatest risk of loss of life. This includes areas in the floodplain where the flood water velocity (feet per second) multiplied by the flood water depth (measured in feet) would equal or exceed four feet or where flood water depth alone would equal or exceed four feet. Legend Effective Bear Creek High Hazard Zone Proposed Bear Creek High Hazard Zone Effective Other Creeks High Hazard Zone Revised Boulder Creek High Hazard Zone Proposed Skunk Creek High Hazard Zone Levee Creek Ditch City Limits Bear Canyon Creek 01252505007501,000Feet Proposed High Hazard Zone 1:4,000 Compared to FEMA Effective The information depicted on this map is provided as graphical representation only. The City of Boulder provides no warranty, expressed or implied, as to the accuracy and/or completeness of the information contained hereon. Utilities Division © 2014 City of Boulder, CO Subject to Revision - Revised: 7/9/2014 Attachment D DRY CREEK NO.2 Lee Cr Dallas Pl Legend Effective Bear Creek 500 Year Floodplain Proposed Bear Creek 500 Year Floodplain Effective Other Creeks 500 Year Floodplain Revised Boulder Creek 500 Year Floodplain Levee Creek Ditch City Limits Bear Canyon Creek 01252505007501,000Feet Proposed 500-Yr Floodplain 1:4,000 Compared to FEMA Effective The information depicted on this map is provided as graphical representation only. The City of Boulder provides no warranty, expressed or implied, as to the accuracy and/or completeness of the information contained hereon. Utilities Division © 2014 City of Boulder, CO Subject to Revision - Revised: 7/9/2014 31st St 0 Legend 31st St 0 Legend 31st St 0 Legend Attachment H Lower Bear Canyon Creek and Upper Boulder Slough Floodplain Mapping Revisions The tables below present a summary of how the proposed floodplain mapping revisions impact existing structures. Summary of Proposed Changes Lower Bear Canyon Creek Number of Structures 100-Year FloodplainConveyance Zone High Hazard Zone Existing Floodplain 64 0 0 Proposed Floodplain 39 0 0 Change-250 0 No Longer Affected 37 Newly Affected 12 No Change 27 Upper Boulder Slough Number of Structures 100-Year Floodplain Conveyance Zone High Hazard Zone Existing Floodplain 38 0 0 Proposed Floodplain 65* 11 2 Change +25* 11 2 No Longer Affected 19 0 0 Newly Affected 40 11 2 No Change25* 0 0 * Includes 6 structures that are within the Boulder Creek 100-year Floodplain. C I T Y O F B O U L D E R WATER RESOURCES ADVISORY BOARD INFORMATION ITEM MEETING DATE: July 21, 2014 AGENDA TITLE: Information Item – South Boulder Creek Flood Mitigation Planning Study Status Update FROM: Jeff Arthur, Director of Public Works for Utilities Bob Harberg, Principal Engineer - Utilities Annie Noble, Flood and Greenways Engineering Coordinator Kurt Bauer, Engineering Project Manager EXECUTIVE SUMMARY The purpose of this memorandum is to provide a general summary of the history and progress made to date on the South Boulder Creek flood mitigation planning study. This mitigation plan was initiated in 2010 after the floodplain mapping was updated in 2007. Since the study was initiated, multiple flood mitigation alternatives have been evaluated to address flooding associated with South Boulder Creek. A consultant recommendation has been developed and is described in this memorandum. A more detailed description of the recommended alternative will be presented and a request for a motion from the WRAB will be made at a meeting Attachment A scheduled on August 18. shows the location of the study area. Hydraulic modeling indicates that a major storm event will cause water from South Boulder Creek to overtop US36 near Table Mesa Drive and result in flooding through the West Valley (area generally located west of South Boulder Creek, north of US36, east of Foothills Parkway and south of Arapahoe Avenue). The September 2013 flood event did overtop US36, causing an estimated $45 million in flood damage. A flood mitigation planning study began in early 2010 with a focus on developing and evaluating alternatives designed to mitigate flood hazards affecting structures and areas along South Boulder Creek and the West Valley within the current incorporated city limits. Conceptual alternatives were initially developed by problem area in a matrix format that included a wide range of mitigation measures. These concepts were then presented at a public meeting and subsequently combined into 15 Alternative Plans. These alternatives were Agenda VI Page 1 evaluated and nine Best Alternative Plans were developed and presented at a second public meeting and to WRAB in late 2010. Four of the nine Best Alternative Plans were further refined and analyzed and the consultant team selected an engineering recommendation. Major components of the consultant recommended alternative include construction of a regional stormwater detention facility south of US36, a smaller detention facility at Manhattan Middle School and one at Flatirons Golf Course. The recommended alternative would provide significant flood protection within the West Valley area, including eliminating the 100-year floodplain designation that currently affects approximately 700 structures. The estimated cost of the alternative is approximately $46 million, but the project could be constructed in three phases. Construction of the project would require numerous permits, agreements with the University of Colorado and Boulder Valley School District, disposal of Open Space and Mountain Park land and would be regulated by the State as a high hazard dam. Construction of the regional detention facility at US36 would result in significant impacts to wetlands, habitat for threatened and endangered species and other environmental and aesthetic resources. BACKGROUND In the mid-1990s the University of Colorado (CU) was evaluating the purchase of the South Campus located at US36 and Table Mesa. During this evaluation, inaccuracies in the 1986 regulatory flood mapping were discovered. In 1997,the city, Boulder County, the Urban Drainage and Flood Control District (UDFCD) and the Colorado Water Conservation Board commissioned a flood study to verify the results of the CU study and to compare the results to the adopted floodplain mapping. The 1997 study was not approved and a new flood study, using more advanced hydraulic modeling and hydrology techniques, was commissioned by the city and the UDFCD in 2002. The 2002 study included a Climatology and Hydrology Report and was reviewed by an independent review panel, citizen advisory group and a hydrology advisory panel. The study was completed in 2007 and resulted in a new flood map and formally identified the flood hazard that would impact the West Valley neighborhoods west of South Boulder Creek and north of US 36. The updated floodplain mapping determined that about 700 structures (with a total of approximately 1,200 dwelling units) are located in the 100-year floodplain. The majority of these structures are located within existing developed areas of the city within the West Valley area. A Risk Assessment completed in June 2009 estimated a 100-year event would result in $215 million in property damages. South Boulder Creek has flooded in the past, including in 1938, 1950s, 1969 and in 2013. The flood events in 1969 and 2013 resulted in overtopping of US36 and substantial flooding in the West Valley. South Boulder Creek had the greatest reported property damage from the 2013 flood of all the city’s 15 major drainageways at $45.3 million. The 2013 flood is estimated to Agenda VI Page 2 have resulted in flows above a 50-year event but below the 100-year flow used in the Risk Assessment to estimate damages. ANALYSIS The South Boulder Creek Flood Mitigation Planning Study began in early 2010 and is being funded by the city and the UDFCD. A consulting team from CH2MHill was selected to perform the study. The study is focused on developing and evaluating alternatives designed to mitigate flood hazards affecting structures and areas within the current incorporated city limits, primarily Attachment A). within the West Valley area ( Conceptual alternatives were initially developed by problem area in a matrix format that included a wide range of mitigation measures. These concepts were then presented at a public meeting held in March 2010 and subsequently screened from input received at the meeting, hydraulic modeling and field visits. The concepts were then combined into 15 Alternative Plans. These alternatives were evaluated and nine Best Alternative Plans were developed and presented at a second public meeting in September 2010. The nine conceptual alternatives were presented to WRAB in December 2010. Staff recommended five alternatives be selected for further refinement and analysis. WRAB motioned to move forward with four of the nine alternatives (a pipe alternative was eliminated) including: 1.Maintaining the status quo; 2.High hazard and critical facility protection; 3.Regional detention at US36 with downstream improvements; and 4.Distributed regional detention. Based on further analysis of the four alternatives, the consultant team has selected the Regional detention at US36 with downstream improvements as the engineering recommendation. Four sub-alternatives were developed for the regional detention at US36 facility: 1.A wall centered on the US36 median barrier; 2.A detention facility located on some of the current US36 expansion project right-of-way; 3.A detention facility located outside of the current US36 expansion project; and 4.A detention facility located outside of the ultimate configuration of the future US36 corridor. The US36 median barrier alternative was found to be technically infeasible and was eliminated from further consideration. A traditional earthen berm, concrete wall or combination could be used to contain the storm water for the regional detention at US36 facility. The engineering recommended alternative includes the following major components: An approximately 75-acre (560 acre-feet of storage) regional flood detention facility located primarily on University of Colorado South Campus land (the concept does not impact the South Campus concept development plan) with a portion of the berm located on Open Space land. A 25 acre-foot stormwater storage facility at Manhattan Middle School, a nine acre-feet detention storage area at the intersection of Foothills Parkway and Baseline Road and Agenda VI Page 3 placing a segment of Dry Creek No. 2 Ditch in a 72-inch diameter pipe. It should be noted that the city recently commissioned an analysis of the potential for detention on the Hogan Pancost property as an alternative to or in addition to the Manhattan Middle School detention facility. This analysis should be available in August. A 58 acre-foot stormwater detention facility at Flatirons Golf Course by constructing earthen berms near Arapahoe Avenue. The alternative would provide 100-year flood protection within the West Valley area at an estimated cost of approximately $46 million. The mitigation project could be constructed in up to three separate phases: 1.Regional detention facility at US36 ($23 million); 2.West Valley improvements ($11 million); and 3.Arapahoe Avenue detention ($12 million). Attachments B-D graphicallypresent the major components of the engineering recommendation. Construction of the project would eliminate the overtopping of US36 and subsequent flooding in the West Valley during a major storm event, significantly reducing the flood risk including eliminating the 100-year floodplain designation that currently affects approximately 700 structures. Construction of the project would require numerous permits, agreements with the University of Colorado and Boulder Valley School District, disposal of Open Space and Mountain Park land and be regulated by the State as a high hazard dam. Construction of the regional detention at US36 facility would result in significant impacts to wetlands, habitat for threatened and endangered species (Preble’s meadow jumping mouse, Ute Ladies’-tresses orchid) and other environmental and aesthetic resources. A 100-year event would result in inundation of approximately 37 acres of city Open Space lands for up to a 72-hour period of time. The project website located at www.southbouldercreek.com provides additional information on the flood mitigation planning study along with a draft report. Information about the city’s floodplain management program, floodplain regulations and flood insurance including how mitigation planning fits into the city’s floodplain management process can be found at: https://www-static.bouldercolorado.gov/docs/Floodplain_Management_Overview-1- 201407141157.pdf NEXT STEPS A more detailed description of the recommended alternative will be presented and a request for a motion made at the August 18 WRAB meeting. Prior to the meeting, staff will hold an open house to provide an additional opportunity for the public to review study information, ask questions, and provide feedback. Due to the impacts of the recommended mitigation alternative on city Open Space, the Open Space Board of Trustees will also review the study and make a recommendation to City Council. A study session with City Council is tentatively scheduled for September 30. Agenda VI Page 4 ATTACHMENTS Attachment A – Study Area Attachment B – Consulting recommendation overview Attachment C – Conceptual plan of the regional detention at US36 facility Attachment D – Concept plan of the Manhattan Middle School detention facility Attachment E – Concept plan of the Arapahoe Avenue detention facility Agenda VI Page 5