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Information Item: Wonderland Creek Community and Environmental Assessment Process (CEAP) CITY OF BOULDER INFORMATION ITEM FOR: ENVIRONMENTAL ADVISORY BOARD - August 4, 2010 TRANSPORTATION ADVISORY BOARD - August 9, 2010 WATER RESOi1RCES ADVISORY BOARD - August 16, 2010 PLANNING BOARD - August 19, 2010 PARKS AND RECREATION ADVISORY BOARD - August 23, 2010 OPEN SPACE BOARD OF TRi1STEES - August 25, 2010 GREENWAYS ADVISORY COMMITTEE AGENDA ITEM MEETING DATE: August 31, 2010 SUBJECT: Draft CEAP for Wonderland Creek Greenways Improvement Project Foothills Parkway to Diagonal Highway REQUESTING DEPARTMENT: Anne Noble - Greenways Coordinator Kurt Bauer - Engineering Project Manager Utilities Division PURPOSE: A summary of the draft CEAP is being provided to board members as an information item. It is requested you review the full CEAP available on the Greenways webpage under "Current Greenways Projects and Opportunities" and forward any comments or concerns regarding the draft CEAP to your Greenways Advisory Committee representative. If you have questions on this material, please contact Kurt Bauer at 303-441-4232 or BauerK(c~),bouldercolorado.gov. The full CEAP is available at: http://www.bouldercolorado.gov/index.php?option=com_content&task=view&id=12383&Ite mid= 1189 GREENWAYS ADVISORY COMMITTEE ACTION REQUESTED: A recommendation from the Greenways Advisory Committee to City Council concerning the Wonderland Creek Greenways Improvement Project Foothills Parkway to Diagonal Highway CEAP is requested. Attached is the Executive Summary from the Wonderland Creek Greenways Improvement Project CEAP along with a summary of the CEAPers comments and how they were addressed. 1 WONDERLAND CREEK GREENWAYS IMPROVEMENT PROJECT FOOTHILLS PARKWAY TO DIAGONAL HIGHWAY LEAP EXECUTIVE SUMMARY The proposed Wonderland Creek Greenways Improvement Project from Foothills Parkway to the Diagonal Highway would provide flood mitigation improvements and a multi-use path connection. The project is presented in two phases. The first phase extends from Foothills Parkway to the intersection of Iris Avenue and 34th Street. The second phase extends from the intersection of Iris Avenue and 34111 Street to the Diagonal Highway. In each phase of the project, two flood alternatives and three path alignment alternatives were evaluated. In addition, in Phase I of the project, three railroad crossing alternatives were considered and in Phase II, three alternatives for crossing Iris Avenue were reviewed. A multi-use path system exists along Wonderland Creek from 3011 Street and the Diagonal Highway northwest to 26th Street and from Foothills Parkway southeast to Goose Creek, connecting to Valmont City Park and the Boulder Creek Path. There is a multi-use path running north-south along Foothills Parkway on both the east and west sides. The path on the west side was constructed in 2006 to connect two UCAR facilities which are on either side of Foothills Parkway. This path parallels the Burlington Northern Railroad and terminates at Center Green Drive, but is slated to be extended south to Goose Creek (with an at-grade connection at Valmont Road) this fall. There is currently no path connection between Foothills Highway and the Diagonal Highway. Local residents and users of the path system frequently use an informal route located within the railroad right-of-way. Use of this informal route has resulted in near fatal injuries caused by train traffic. A proposed multi-use path connection is shown for this area in both the Greenways and Transportation Master Plans. The Community and Environmental Assessment Process (CEAP) is a formal review process to consider the impacts of public development projects. The purpose of the CEAP is to assess potential impacts of conceptual project alternatives in order to inform the selection and refinement of a preferred alternative. The CEAP provides the opportunity to balance multiple community goals in the design of a capital project by assessing a project against the policies outlined in the Boulder Valley Comprehensive Plan and department master plans. Three alternatives were evaluated for crossing of the railroad including an at-grade crossing ($624,000), an underpass option ($66,000 - bridge cost included in flood mitigation alternative) and an above-grade crossing ($1,858,000). Three trail alignment alternatives were presented for both phases - southern routes ($533,000 total both phases), northern routes ($501,000 total both phases) and an alignment along Wonderland Creek ($1,134,000 total both phases). Three options were evaluated for a trail crossing of Iris Avenue including two at-grade crossings - one at Bridger Trail ($166,000) and one at 34tH Street ($168,000) and one underpass option ($63,000 - cost for culvert included in flood mitigation alternative). In addition to the three alignment alternatives, a short connector trail between Hayden Place and Spring Creek Place is recommended ($28,000). Wonderland Creek between the Diagonal Highway and Foothills Parkway is currently undersized to convey the estimated flow resulting from the 100-year event. The floodplain extends well beyond the creek banks and includes numerous structures. A set of box culverts 2 located under Foothills Parkway was designed to convey Wonderland Creek southeast under the highway. The creek, however, currently discharges directly to the Boulder and Whiterock Ditch just west of Foothills Parkway. This configuration has caused the ditch to overtop east of Foothills Parkway, resulting in flooding in the Kings Ridge Subdivision. Two flood mitigation alternatives were evaluated to separate Wonderland Creek from the Boulder and Whiterock Irrigation Ditch and connect the creek to the existing box culverts under Foothills Parkway. One alternative would separate the creek from the ditch and convey all flow to the existing box culverts under Foothills Parkway via a single new railroad bridge ($1,566,000). The second alternative would separate the creek from the ditch but convey flow to the existing Foothills box culverts in two paths ($1,541,000). Low flows would be conveyed using the existing railroad bridge and high flows using a new railroad bridge that would be slightly smaller than the one proposed in the first alternative. Two flood mitigation alternatives were evaluated for conveyance of Wonderland Creek under Iris Avenue (currently no formal conveyance exists and the creek ends just upstream of Iris Avenue). One alternative would convey Wonderland Creek under Iris in one large set of culverts followed downstream by a segment of concrete channel ($1,705,000). The second alternative would convey flow in two parallel culverts, one designed to convey smaller flows to an existing open channel segment and a larger one to bypass high flows to Wonderland Creek downstream of 34th Street ($1,434,000). High Hazard containment and 100-year containment were considered for both sets of flood mitigation alternatives. The following presents staff recommendations based on the draft CEAP review. The split flow alternative ($1,541,000) is recommended for flood mitigation near Foothills Parkway because it is slightly less expensive than the single flow, larger bridge alternative. The underpass option ($66,000 - bridge cost included in flood mitigation alternative) is recommended for the trail crossing of the railroad because it would take advantage of the flood mitigation bridge and the public prefers this route, and a grade separated crossing. The alignment along Wonderland Creek ($638,000) is recommended for extension of the trail from Foothills Parkway to the intersection of 34th Street and Iris Avenue. This alignment is recommended because it is preferred by the public, it is the most direct, it would provide the best user experience, would have the least conflict with vehicles and would provide access for flood maintenance of the creek as required by the city and the Urban Drainage and Flood Control District. This alignment is, however, considerably more expensive and would have more environmental impacts than the other alignment alternatives. The trail would be located on previously disturbed areas (mowed grass) and staff believes the environmental impacts can be fully mitigated onsite and habitat enhanced. An at-grade crossing of Iris Avenue at Bridge Trail ($166,000) is recommended as it is the least expensive crossing alternative and would have slightly less vehicle conflicts than the 34th Street at-grade crossing alternative and the public was not opposed to an at-grade crossing of Iris Avenue. The storm water bypass alternative ($1,434,000) is recommended for conveying Wonderland Creek under Iris Avenue. This alternative is recommended because it is less expensive than the single large culvert with concrete channel, would not disturb the vegetated open channel segment located along Iris Avenue between 34th Street and Bridger Trail and would not require relocation of a sanitary sewer line. 3 The Iris Avenue alignment ($182,000) is recommended for extension of the trail from Bridger Trail to the existing path located along 30"' Street. This alignment is recommended because it is the least expensive alternative, will have little to no environmental impacts and the city has all of the rights-of-way required to construct this trail segment. During the Fourmile/Wonderland Creek Final Plan review, Council stipulated that for this reach of Wonderland Creek, 100-year flood mitigation could only be recommended if substantial outside funding is secured. Staff recommends designing flood mitigation for 100-year conveyance capacity as the estimated cost difference is only $36,000 greater than providing only High Hazard Zone containment. The Urban Drainage and Flood Control District funding will more than provide for the cost difference between High Hazard containment and 100-year conveyance. Total estimated concept-level cost for project recommendations is $4,055,000 ($2,273,000 for Phase I and $1,782,000 for Phase II). 4 Wonderland CEAP Summary of CEAPers Review General comments/discussion: ■ Add the transportation CIP project on Foothills to the section on other CIP's (page 16 #4) Project has been added ■ Reference Trails Map on page 2 Reference added ■ Consider adding an executive summary Executive summarv has been added ■ Consider adding a pro/con in Section 4 - Preferred alternative Section 4 has been revised ■ Adding the maps into the document at the relevant alternatives analysis Maps are now included in the relevant sections ■ Consider adding a table of contents Table of contents has been added ■ Page 6: Phase 1 flood mitigation options - add "feet" in the description of the barrier wall Length of barrier walls has been added ■ Page 7: Last paragraph above table - should "easement" be plural? No change to text ■ Page 9: last paragraph - remove the word "staff. Sentence has been reworded ■ Page 15: Facilities and Services: Explain how the project meets the Urban service standards in the BVCP. In addition, look at the following policies in the BVCP and briefly explain how the project furthers these policies - 3.10, 3.13, 3.14, 3.20? This project is located in a filly developed area and therefore the BVCP Frameworkfor Provision of Urban Facilities and Services is not applicable. Text has been added relating to the Utilities and Parks and Trails policies. ■ Environment: Same here, look at policies 4.06, 4.08, 4.09, 4.14, 4.21-4.24, 4.26, 4.31. Text has been added stating that this project will further the BVCP Environmental policy goals ■ Transportation: A big goal/policies in BVCP are multi-modal options. Mention that here. Text has been added ■ Social: look at BVCP section, will this project provide additional protection or emergency access to the congregate care (senior) living facilities? Text has been added ■ Page 16: #2 - Also mention BVCP Trails Map. #4, Transportation Plan should be Transportation Master Plan Text has been added referencing the BVCP trail map showing proposed trail connections 1. Does staff agree with the impact assessment? Yes. Staff recommends checking on if the trail section within the wetland buffer trigger 9-3-9, BRC? If yes, look at what the mitigation options will be or a different alternative. Staff have coordinated on this issue and the Phase II trail alignment recommendation has been changed from Wonderland Creek to Iris Avenue. 2. Does staff agree with the preferred alternative as identified by the project manager? 5 Yes. Staff agrees with the alternative as outlined. Some comments: ■ Clarify the costs of the $84,000 with footnotes Clarifying footnotes have been added ■ Indicate the preferred alternatives on the chart on Page 6. Preferred alternatives are now highlighted in yellow in the table ■ Additional explanation/justification of the recommended alternative along wonderland Text has been added and the Phase II trail alignment recommendation changed from Wonderland Creek to Iris Avenue ■ Pg 30 - Add maintenance cost Maintenance costs cannot be estimated at this conceptual level but city maintenance staff have reviewed and concurred with the recommendations 3. Are there community issues or public processes that should be addressed? No. Staff recommended notifying attendees of the meetings about the GAC CEAP hearing. Post card mailings will be sent out notifying the public of the GAC meeting 4. Is the CEAP ready for board review? Yes. Staff group agreed that it would go as an info item to all the GAC boards, then have a GAC hearing to consider approval. Staff in attendance: Kurt Bauer, Utilities; Joe Castro, FAM; Annie Noble, Greenways; Stephany Westhusin, PW Transportation; Chris Meschuk, Planning; Marie Zuzack, Planning; Bev Johnson, Planning 6