Loading...
5 - Matters from the Board, Review and Feedback on the Broadway Reconstruction Project CEAP, Attachm (2)ATTACHMENT A ' Broadway Reconstruction Project CEAP ~ ,~ ,-- .~ CITY OF BOULDER ~...~ ,^^ ~.. Department of Public Works/Traosportation Division PO Box 791 1739 Broadway Boulder, Colorado 80306 (303)441-3266 (303) 447-4271 FAX . / /' ,,,,,~~~-:~ ~ ~ TO: Planmng and Development Services FROM: Noreen Walsh and Alex May, Transportauon Div~sion SUBJECT: Broadway Reconstrucuon Project CEAP DATE: September 4, 2001 Attached aze 15 sets of the Community and Envuonmental Assessment Process (CEAP) document and preliminary plans for the above referenced pro~ect for review and comment by the Development Review Commrttee. T'tus project is a capital improvement pro~ect and is recommended as part of the City's approved Transportauon Capital Improvement Program. The City of Boulder, Colorado Department of Transportauon and the Federal Highway Admimstrauon ~omtly fund ttus $7.6 nullion pro~ect The followmg is the anticipated remaimng schedule for tkus pro~ect, • Subnut prehm. plans and CEAP for Crty review/approval • F I R. meeung w/ CDOT & affected urihries • Submit Floodplazn Development Peruut Apphcauon • Subnut City Wetland Pemut ApphcaUOn • CEAP recommendauon by TAB (tentadve) • CEAP considerahon by Boulder Crty Council (tentaave) • F O R. meeung w/ CDOT & affected uulit~es September 13, 2001 Eazly October, 2001 Eazly October, 2001 Late October, 2001 Ivud November 2001 Mid November 2001 Mid December 2001 Ivud December, 2001 Eazly/Mid Jan. 2002 Mid December 2002 with key target dates hsted. September 4, 2001 • City Wefland and Floodplain Dev. Permits Issued (anucipated) • Advertise Pro~ect • Start Constructron • End Constructaon (Some Final Fmish/Landscape, Spnng 2003) Due to the requirements associated with the federal funds for ttus pro~ect, the above schedule dates aze important to meet Therefore, we aze subm~tang ttus CEAP document to the DRC review process during thts "on week" in order to obtazn review comments prior to Board and City Council consideradon of this pro~ect. Your assistance will be greatly appreciated. Please call either of us at extension 3266 if you have any quesuons or require any addiuonal mformation Enclosures cc (w/ CEAP)• George Tsiouvazas - Carter Burgess Steve Tuttle - Transplan Rick Moser - Moser and Assoc~ates David Love- Love & Associates, Inc. Jerry Shapms - Shapms Associates (w/o CEAP). Stephany Westhusm-Transportation Mike Sweeney- Transportahon ~ Bob Hazberg- Utiliues Alan Taylor- Dev. Review Bob Sadighian - CDOT, Reg~on 4 COMMUNITY AND ENVIRONMENTAL ASSESSMENT PROCESS BROADWAY RECONSTRUCTION PROJECT r„ (UNIVERSITY TO PINE) ~ PREPARED FOR: City of Boulder Public Works Department Transportation Division PREPARED BY: Ccrter=Burgess ~ TABLE OF CONTENTS ~ Descnption and Location of the Project ............. ........................... ...........1 Background, Purpose and Need for the Project ........................................2 Roadway ....................................................... ................................... 2 Bridge Structure ................................... .......... ...................... ... .......2 Floodpf am .. ........................ .............. ........................ .. ....... ........... 3 Multi-use Path ................................. .. ............. ........... ....... ...........3 Summary of Purpose and Need ........... ...... ...... . . ............... ........ ..4 Description of Project Altematives and Summary of Ma~or Issues . ...........4 Roadway Aitematives ............................................................. ...........4 Bridge Altematives ......................... ................ ................... .. .......... 5 Streetscape Altematives ................................... ............. ...... ...........7 Construction Traffic Impacts ............... ........................... . ..... ..........17 Preferred Project Aftemative .......................................................... .....••••..13 Public Input to Date .................. ....... ........ .... .. ................. .......... ..........14 Goals Assessment ...... ...... ............... ....... .... . ........ ......... ... .... ...........15 Impact Assessment .................................... ....... ....... . ............... . .........18 Natural Areas ......................................................................... ......... .19 Riparian Areas and Floodplains ............................................. ...........20 Wetlands .......................... ...... ....... .. .... ...... .. . ................. ....... ...20 ,~.~, Geology and Sods ...... ......... .......... . ............... . ........ . ...... ..........21 .~.~ Water Quality ..... ........ ...... . .... ............... ........ . . ....... . . ... ..........21 Air Quality .. . . . ...... ....... ...... ....... .. .............. ......... ....... ..... ..23 Resource Conservation ...... ........ ...... .... ..................... . . .. .... ......23 CulturaVHistonc Resources .. ........... .... ........ ............. ....... ...........24 Visual Qualiry .............. ....... ........ . ..... .... ..... ........... ....... . . . .......24 5afety ............................... . .................. ....... ............. ........ . ..... . ... 24 Physiological Well-Being ....................... ............ ..... ..... . ..... ... . .....25 S e rvices .................... . .... .. . ........ .............. ....................... .. ..... . 25 Special Populations .............. .............................. ........... .. ..............26 ~ ~ CITY OF BOULDER ~ COMMUNITY AND ENVIRONMENTAL ASSESSMENT PROCESS FOR BROADWAY RECONSTRUCTION PROJECT (UNIVERSITY TO PINE~ Description and /ocation of the project: Project Description Broadway (Colorado State Highway 93) is classified as a Pnncipal Arterial that runs north and south in the city of Boulder. In the area of the project, Broadway is a 4-lane urban section carrying approximately 30,000 vehicles per day. It is one of the city's multi-modal corridors servmg automobile, pedestrian, bicycle, and transit modes. The Broadway Reconstruction Project is made up of two separate interrelated pro~ects: roadway reconstruction between Unroersity Avenue and Pine Street and reconstruct~on of the bridge over Boulder Creek. The roadway reconstruction project abuts the bridge reconstruction pro~ect to the north and south. The overall pro~ect includes reconstruction ,.- of Broadway, replacement of the Broadway bndge over Boulder Creek with ~,,,,r improvement to the existing grade-separated crossing of Broadway at Boulder Creek, local storm drainage improvements and flood control improvements to Boulder Creek. The roadway reconstruction project has received Federal funding through the Transportat~on Improvement Program (TIP) from the Denver Regional Councd of Govemments (DRCOG). The southem limits of the roadway reconstruction project are between University Avenue and Arapahoe Road; the northem limtts are between Canyon Boulevard and Pine Street. In both, the new roadway will be reconstructed ~n concrete pavement. The total length of roadway to be reconstructed between Universiry Avenue and Pme Street is approximately 3500 linear feet. There wdl be no increase m number or width of travel lanes. The estimated cost of this pro~ect is $3.6 mdlion, funded by FHWA ($1.8 million), CDOT ($0.9 million), and the City of Boulder ($0.9 mdlion). The roadway section of the project was onginally scoped as a Major Street Reconstruction category (MSR) pro~ect and submitted in 1999 to DRCOG through the TIP application process. It was scored as the second highest priority MSR project in the metro area. Further analysis of corridor deficienaes has identified additional streetscape/landscape, pedestrian, bicycle and transit facility needs m the corridor. The bndge reconstruction project was origmally scoped by the Colorado Department of Transportation (CDOT) as a bridge replacement project to replace the existing 100-foot long bndge over Boulder Creek includmg required approaches and adjacent roadway ~ reconstruction between Arapahoe Road and Canyon Blvd. As part of CDOT's capital ~, improvement planning, the structural condition of the bridge was ident'rfied in the 1980s ~w as being structurally deficient and the bridge continues to be one ot the lowest rated on- system structures in CDOT Region 4. The estimated cost of this project is $4.0 million, funded by FHWA and CDOT ($3.5 mdlion) and the City of Boulder Public Works - Transportation and Utilities Divisions ($0.5 million) for bridge enhancements and fiood related work. Background, purpose and need for the project Roadwav Broadway (Colorado State Highway 93) is a major urban arterial traversing the ent+re City of Bouider, Colorado. The existing pavement was last overlaid in the ea~ly 90's and due to heavy traffic loads and volumes is detenorated, cracking and very badly rutted. In addition, many overlays have raised the crown of the street above the adjacent curbs, producing excess cross slope and reducing the drainage function of the roadway. The steep cross slopes exceed 8 percent in some areas, and make traversing the intersections difficult for mobility impaired citizens. This condition also amplrfies the outside wheel loads for buses and heary truck traffic, compounding the pavement maintenance problems the city and CDOT have expenenced. ~ Bridae Structure ~ Between Arapahoe Road and Canyon Boulevard, Broadway crosses Boulder Creek and the Boulder Creek Path. The Broadway bndge was constructed in approximately 1921 to replace a truss-type structure. The two-span structure is about 100 feet long and ~s constructed of concrete abutments/pier, with steel I-girders spaced on approximately 3- foot centers. A cast-in-place concrete deck spans the girders and is covered by an asphalt surface. The bndge has a false-arch fa~ade, decorative bridge rails, and fighting pedestals on each comer that contnbute to ds identify. The bndge has experienced deterioration retated to age, traffic, road ma~ntenance and hydraulic scour forces. General areas of concem include: - Inadequate conveyance of major flood event. - Required intenm (short term) repairs to the foundation to address distress m supports includmg repairs to three foot deep voids in the pier wall. - Deterioration of the structural steel has caused significant loss of structural capacity at the pier. - Concem of catastrophic failure related to existing foundations that bear directly on underlying soil and are not safely embedded into bedrock. ,~-+. 2 . ,.-, +,,,.. - Deck detenoration and section loss at curb lines. - Bridge rail does not meet acceptable traffic load cnteria. - Lead based paint on steel stringers. Fioodplain Currently, Boulder Creek has a very wide 100-year floodplain that covers the area from south of Arapahoe Road to north of Canyon Boulevard, and overtops Broadway. The Ciry of Boulder Municipal Building is within the high hazard zone of this floodplain. A ma~or constramt for this floodplain is the Broadway bndge and the existing concrete dam on the downstream side that senres an irrigation head-gate. Improving and maximizing the flood carrying capacity (both now and in the future) of the bridge has been a major consideration dunng the design of the facility. Multi-use path Ad~acent to the creek and beneath the bndge is the multi-use path (Boulder Creek Path) that was constructed to provide a grade separated under crossing of Broadway for pedestrians and bikes. This path is a very important connector between vanous Civic Center uses including Central Park, the Municipal Building and the Main Library. This ~ path serves as the primary pedestnan crossing pomt during the many festivals held throughout the year. This section of path is part of the Boulder Creek Path, an 8-mile long, major east-west bicycle corridor m the aty. The path is frequently flooded during heavy rainstorms and sustained high spring runoff in some years. The divider wall constructed between the path and the creek is often overtopped and the path must be closed. The height of the divider wall was constrained at the time of construction by the existing bridge opening and the floodplain design critena. As part of the Broadway Reconstruction Pro~ect, this path would be replaced and widened. It wdl also have improved flood protection although it may not be possible to keep it open dunng all flood events. Improving the width and dramage condition of the path without adversely affecting the floodplain in the area can only be accommodated by widening the opernng of the bridge. ~"'^^ ~ SUMMARY OF PURPOSE AND NEED This project wouid completely reconstruct the section of Broadway (S.H. 93) from University Avenue north to Pine Street. The purpose and need for the Broadway Reconstruction Project is summanzed as follows: - The deteriorated roadway pavement needs to be replaced, and reconstructed to concrete, in order to withstand the high volume, muRi-modal, urban arterial traffic on this roadway, and reduce the long-term life cycle costs of maintaming this roadway. - The cross-section crown is particularly steep due to years of overlays on the pavement surface and needs to be reconstructed and reduced for better accessibility, improved drainage function and a more uniform cross section. - The bndge over Boulder Creek needs to be reconstructed due to the detenorating structure condition. - The span of the bridge needs to be increased in order to better handle the flood flows associated with Boulder Creek and reduce the penod dunng which the path is now inundated, and to provide for potential future reduction of flood hazards m the area ^~ ~~ - The multi-use path under the bridge needs to be widened to accommodate improvements necessary for better pedestnan and bike traffic flow. ~ - The multi-use path needs improved flood protection so that it can remain open ~-^ during heavy rainfall events and annual spring runoff. - Enhanced transit facilities. - Enhanced pedestrian walkways and multi-use path. - Enhancedlandscape. Description of project a/ternatives and summary of major issues: The Broadway Reconstruction Pro~ect is a mufti-faceted project, which reqwred an evaluation of altematives for the vanous improvements and project issue areas. Roadwav Alternatives The roadway altematives evaluated for this pro~ect included: • Maintain historical roadway lane widths, which would reqwre vanances from CDOT and FHWA. • Increase roadway lane widths to meet current standards. • Use of asphalt or concrete pavement types. ~ ,~^ ~ Since most of Broadway has been developed to the public right-of-way line, increasing the roadway lane widths would require the reduction of sidewalk widths and loss of trees that are adjacent to the existing roadway curb. Accident data along the Broadway comdor does not mdicate an unusual accident history or demonstrate a need for lane widening. This is summanzed in Appendix D. During the altematives evaluation several pedestrian improvements have been identrfied. These improvements include widening the Boulder Creek Path under Broadway, constructmg a wider detached sidewalk in front of the municipal building, elimmatmg the two-level sidewalk in the area of Pearl Street mall, and improving curb access ramps at all intersection comers. Concrete pavement has been selected for this street reconstruction to better accommodate the high traffic volumes and heavy bus traffic on the roadway, while minimizing the overall life-cycle costs of maintaining the pavement. Evaluation of noise impacts between different pavement types and finishes have also been evaluated for the pro~ect. This is summarized in Appendix H. Bridqe Alternatives: The project has evaluated eight different bndge altematives. Several of the discussed altematives are required analysis for Section 106 review of the National Historic '~ Preservation Act (NHPA) and Section 4(f) of the Department of Transportation Act of 1966. The followmg brief discussion presents the process followed in examining each altematroe and arriving at a preferred altemative. Staff and consultants met with the Ciry of Boulder Landmarks Preservation Adwsory Board (LPAB) at their May, June and July meetings to get their input on the bridge altematives and historic analysis. Altemative A: No Action/No Bwld. This altemative must be presented as a baseline for comparing the environmental impacts of each altemative under consideration. This altemative fails to address the purpose and need for the project m terms of motorist and pedestnan/path user safety, hydraulic concems and recreational amenities. For these reasons, Aftemative A was not selected as the Preferred Aftemative. Altemative B: New Structure at a Different Location. One altemative for preservmg h~storic bridges m place is to build a new structure at a different location to reduce or eliminate the transportation or structural demands being placed on the old bridge. This altemative analysis is required by Section 4(f) of the Department of Transportation Act. Altemat~ve B fails to address the hydraulic and Boulder Creek path functional needs for the project and would also introduce significant environmental, economic and social impacts to the adjacent project area. For these reasons Altemative B was not selected as the Preferred Altemative. ~ "'~, Altemative C: Rehabilitation. To determine the feasibdity of a rehabilitation option for -~ the existing bridge the following actions were performed. • Analysis of existing bridge inspection reports. • Detailed inspection of bridge. • Analysis of bndge maintenance history. • Materiai testing of bridge rail (X-ray). • Floodptain analysis. • Discussions with CDOT to determine bndge railing reqwrements. The information from this analysis was compded and a rehabilitation option formulated. This option would include the removal and replacement of the ma~ority of the bndge including the pier, abutments, bridge deck, sidewalks and interior beams. The option would leave only the fascia beams, railing and end pillars in place. To meet safety requirements, a second railing would be placed adjacent (i.e., inside) to the existing railing See specifics in Attachment A, "Technical Memo on Bridge Rehabditation Altemative". As part of this option a second small bridge, located north of the existmg bndge would be constructed. This new structure would serve to carry bicycles and pedestrians under Bsoadway as well as carry overflow floodwaters dunng a severe storm. Because of the great uncertainty that the important architectural features of the historic bridge would survrve rehabilitation efforts (due to their fragile condition) and the ~ significantly higher costs for this altemative, this altematroe is not recommended as the Preferred Alternatroe. Alternative D: Reconstruction. The replication/reconstruction of historic properties is occasionally selected as a preferred altemative when those properties have been damaged or destroyed, or planned to be replaced. For the Broadway Bridge, replac~ng the structuratly deficient existing bridge with an exact replica would address some, but not all of the safety needs for the project but would not address the identified hydraulic or recreational needs. The Project Team believes the histonc and architectural features of the current bridge are not of such significance that replication is a prudent solution. Therefore, Altemative D was not selected as the Preferred Altemative. Altemative E: Remove Existina Structure to a New Location. Historic preservation planrnng often supports the removal of threatened fiistoric properties to new locations where they can serve useful purposes and remain as important elements of the community. The Project Team 6elieves that the Broadway Bndge is not a candidate for relocation because of the fragile condition of the concrete railings and fascia beams as well as the deterioration of the supporting girders. Even if a suitable adaptive reuse location for the bridge was found, the Team does not believe the concrete work would survive the move. Therefore, Altemative E was not selected as the Preferred Altemative. ~ s W., ~ Altemative F: Demolition of the Histonc Bridae/Construction of a New Structure. Several options for replacing the existing bridge have been considered. These options include one, two and three span configurations and vary in appearance from classic arching structures (similar to the existmg bridge) to very contemporary steel truss structures. Each option is configured to meet the following pro~ect goals: • Structurally sufficient and meets current design standards. • Improves the flood carrying capacity under Broadway. • Can be expanded in the future if additional flood improvements to Boulder Creek are made. • Improves safety for the path users. This altemative is recommended for development as the Preferred Altemative for the Broadway Reconstruction Project. This is the only altematroe that appears to be feasible and prudent while also satisfying all elements of the project purpose and need. See Appendix B to view preliminary Bridge Design Concepts. Altematroe G: Reuse of Histonc Features on a New Bridae. In the event that the historic bridge is tom down, an opportunity exists for preserving some of its significant ~ histonc architectural features by incorporating them on the new, replacement structure. The features include the light fixtures and potentially the light pedestals. The Pro~ect Team recommends that this option be given consideration as replacement bndge designs and ad~acent area improvement designs are developed. Altematroe H. Reuse of Historic Features Elsewhere. Replacement of the existing bridge also creates an opportunity to remove some of the historic architectural features and place them somewhere else in the communfty for interpretive or aesthetic purposes. This option can realistically be considered at any point in time prior to demolition of the existing bridge but unless there is a request from within the community to do this the Pro~ect Team will take no future action on this altemative. Streetscape Alternatives The followmg section described irntial considerations, key issues, and the prelimmary concepts and ideas to improve and enhance the pedestnan settings and sidewalks in the Broadway Corndor. 9) CONSIDERATIONS ~ ^e A Premier Civio Corridor . The Broadway corridor is a premier roadway which serves as the "front door" to Central Boulder and is one of the most successful pedestrian districts in the region. It should receive high qualiry and attractive streetscape improvements which express the unique civic identiry of Boulder, and serve the numerous users who experience Broadway. The Broadway corridor is part of the "public realm" of the Crty, and as sucfi, streetscape ~mprovements developed in tfiis pro~ect should remforce and enhance the appearance and functions of the roadway, sidewaiks and public spaces. The Urban Forest The street trees in downtown provide remarkable and valuable functions of climate modification, buffering, habitat enhancement and aesthetics. There are many areas in the corridor where trees are unhealthy because of the urban setting or lack of maintenance, and there are gaps in the curbside street tree buffer area. This project wdl seek to improve the living environment for trees, and replace unheafthy trees/gaps with new trees. Maintenance Improvements should be designed to ensure maintenance effectiveness and efficiency. It will be important to ensure that maintenance responsibilities and budgets are clanfied between public and private entities to ensure that improvements are well maintained. Planrnnq Context The urban design recommendations must fit within the planning context of the area and ~ mcorporate the ideas developed by other projects These projects include the Civic Center Master Plan; the Mal~ Master Plan; and the Downtown Area Design Guidelines Phasmq Specific funding for the current scope of streetscape work was not anticipated in the origmal pro~ect budget. These budgeting issues will likefy require that some of the streetscape recommendations are phased into other projects. b~ INVENTORY/ANALYSIS AND SUMMARY ISSUES Character Districts The Pro~ect Team completed an extensive existing conditions analysis map which graphically summarizes the attnbutes and issues of the corndor which will be addressed in the design recommendations. The attnbutes and issues of the comdor generally reflect the qualities of three different character districts: The Hill Transition Area from University to South of Arapahoe Road The Civic Area from South of Arapahoe Road to North of Canyon The H~storic Downtown Area from North of Canyon to Pine Street. ,~*, ~ ~..~ ~ ~ Please see the plan graphic which summarizes this analysis in Appendix C. Summary of Existing Streetscape Issues 2. 3. 4. 5. 6. 7. 8. Corridor tree gaps. Segment of deteriorating and unsafe sidewalks. Cluttered sidewalks near the mall. Unmaintained ROW in certain areas. Lack of amenities adjacent to the mall Uncomfortable bus stops. Parking/vehicular area impacts. Lack of distingwshed ciwc identity. C) CONCEPTS AND OPPORTUNITIES OVefdll COnCeptS retail and civic areas. The graphics m Appendix C illustrate a few preliminary ideas which represent the rype and character of proposed streetscape improvement concepts. An overall summary of the concepts are described in the following section. The modest improvements suggested at the comers and "gateways" will provide a safer and more attractive place for people at major intersections. They will also establish key "gateway" points of entry to the downtown area character districts at Arapahoe, Canyon and Pine. At all of the comers, ary standards for curb ramps, sidewalk safety improvements, and comer widenings wdl provide safe pedestnan settings; At the three gateway intersections, modest stone walls, vertical piers, special accent paving and plantings will mark these as distinguishing areas and enhance the appearance and user experience of the corridor. Improvement Concept A: Comers and Gateways Improvement Concept B: Cur6side Right of Way Buffers This is the area between the sidewalk and the curb where street trees are usually planted to provide a buffer between the pedestrian zone and the roadway. This is also the location for street lights, bicycle racks, fumishings and other improvements which do not conflict with pedestrian access and safety. The sketches in this section show typical curbside improvements which are recommended to prowde a safe, maintainable and attractive curbside buffer that are fit to the unique areas of the corridor. Improvement Concept C: Trans~t and C~vic Places The bus stops and the entry areas to public bwldmgs and parks represent a unique opportunity for the City to improve the life of downtown. These are the locations where people meet each other, where special events take place, where people have a memorable expenence. The existing bus stops are difficult to see, and they often are not comfortable or inviting for people as they wait for a bus. The avic "patios" in front of the municipal building and in front of the park central buiiding are afso areas that do not recognize the speciaf qualities of the public realm. The sketches illustrate opportunities to provide new fumishings, signage and shelters for the bus stops, and amenities and fumishings that can be developed at the civic campus These improvements may have to be phased due to current budgetary constraints. Prelimmarv Concept Plan The Iilustrative S~te Plan (see Appendix C) shows a preliminary pattem of streetscape development for the whole corridor. The improvements are summarized by the following design objectives: Overall ~mprovements throughout the corridor 1. Complete sidewalk repair and replacement where needed with standard whrte/scored concrete. 2. Develop a contmuous row of street trees along the curbside. 3. Consider use of potted plants as an additional curbside buffer in retail and civic areas. 4 Develop a consistent and distingwshed system of downtown bus stops. 5. Develop accent piantings at comer widening areas. ,.,4, 6. Continue use of concrete with bnck and stone as accent matenals ,.„ H~II Transition Area 1. Maintam tree lawns in the curbside zones. 2. Establish landscaped medians as a transition element, south of Arapahoe Road. 3 Improve bus stop at Alfalfa's. 4 Repair and replace urban curbside buffer at retad areas. Civ~c Area 1. Establish civic comer °gatewa~' improvements at Arapahoe and Canyon. 2. Consider pedestrian scale lights on whole block. 3. Develop a new civic patio in front of the Park Central Building. 4. Provide curbside street trees. 5. Provide wider tree lawns in the park. 6. Consider Art in front of Municipal Buildmg. 7. Develop a new civic promenade on the west side of Broadway in front of the Municipal Building to link the bndge to the comer of Canyon and Broadway. 8. Develop a new detached sidewalk m the park on the east side linking the bndge to the comer of Canyon and Broadway. 9. Improve bus stops. ~ io ,_ ~ ~ Historic Downtown Area 1. Establish civic comer "gatewa~' improvement at P~ne. 2. Consider pedestrian scale lights on the mall block. 3. Provide more efficient curbside bicycle parking on the mall block. 4. Provide level sidewalks on the mall block and area in front of the Randolph Center by eliminating sidewalk elevation change. 5. Develop seating walUplanters for the "double" signature street trees next to the mall. 6. Consider public art in the ROW. 7. Remove curvilinear walis and pedestnan obstructions on the east side of Broadway between the alley south of the mali and Walnut. Develop a new parking lot buffer composed of an improved bus stop and bicycle storage area. Develop a"Welis Fargo Plaza° on the northeast comer of Walnut and Broadway wh~ch could interpret the histonc stories of downtown merchants, or include the old trolley rail removed from the street, or other public art initiative. Construction Traffic Impacts Broadway carries approximately 30,000 vehicles per day (vpd) on an average weekday. Withm the pro~ect construction limits (Pine Street to University Avenue), Broadway has ~ two northbound and southbound through lanes, with a single center or two-way left-tum lane. The mtersections of Broadway with Pine, Spruce, Pearl, Walnut, Canyon, Arapahoe, and University are controlled by traffic signals, while the remaming mtersections are controlled by stop signs on the minor street approaches. See Appendix D for additional traffic analysis mformation. The two construction phasing altematroes that were looked at are: a. Reconstruction of Broadway closmg one lane in each direction between Pme and University. Total construction time is estimated to be 1 year. b. Close the entire street on Broadway, from University to Pine. Total construction time is estimated to be 8- 9 months. This second construction phasing altemative is not considered to be feasible due to the severe mobility and economic impact that would be incurred due to the lack of access to businesses and the street during this time. Therefore, staff has recommended closing Broadway to one lane in each direction dunng construction. This type of construction phasing was implemented during prewous concrete reconstruction pro~ects on Broadway between Regent and Unroersity in the early 1990's. The reconstruction of Broadway through downtown Boulder will mvolve closing one through lane in each direction between Pme and University, and will result in increased ~ traffic congestion in the project viciniry. In order to mitigate the impacts, vanable 11 "'~ message and fixed signing wdl be used to make drivers aware of the project at decision ~ points well before they reach the downtown area so that aRemate routes may be used It is anticipated that Broadway will be able to service roughly 18,000 vpd during construction. Due to congestion aiong this stretch of Broadway, the remaming 12,000 vpd will seek altemate routes on parallel or adjacent roadways during this time. Based on the Bouider roadway network, d is estimated that roughly half (6,000 vpd) of the diverted traffic will be distributed onto other north-south corndors such as Folsom Avenue, 28~' Street, 30~' Street, and Foothills Parkway. There is capacity on these roadways to accommodate this adddional traffic. These diversions will be encouraged with the use of vanable and fixed message signing at key entryways into Boulder (US36> SH 119, and SH 93). Coordination wrth the 28"' St~eet lmprovement project, which will involve mostly off-peak lane closures on the southem end of 28"' Street, is being undertaken to consolidate message signing and avoid diversion conflicts. Closer in to the Broadway project limits, additional signage will notify local traffic that congestion on Broadway is likely, and aftemate routes are adwsed. It is anticipated that some of the traffic will droert onto 9'" and 17"' Streets, although these roadways will not be suggested as altemate routes. Today, these roadways service approximately 11,000-12,000 vpd (9th) and 7,000-11,000 vpd (17th), respectively, wdhin the study area. It is anticipated that roughly 4,000 vpd wdl divert to 9~n Street, and that roughly 2,000 vpd will droert onto 17~' Street in the immediate vicinity .~ of the pro~ect, with lesser additional volumes once away from the project area, There is ~ capacity on 9`h Street and 17"' Street to service this temporary addition of traffic during construction. Dunng construcUon, two through lanes (one m each direction) will be mamtained with two closed at all times. Left-tum lanes at the majority of the primary signalized intersections will be maintained dunng the majority of the time, although these tanes may be shorter than existing lengths and temporary (off-peak or nighttime) closures or restrictions will occur. Pedestnan sidewalks and the Boulder Creek Path will be accommodated within the construction phasing to allow for mostly continuous access along Broadway and at each intersection. The Broadway multi-use path along the east side of Broadway between Manne and University will not be affected, except for minor detounng dunng work at the Grandview/Broadway intersection. Coordination with RTD is underway to insure that existing bus serwces wtll be mamtained during construction. Some regional and local bus routes may be rerouted to avoid congestion along this stretch of Broadway, although the Skip route will remam along the project length. Temporary consolidation of bus stops and the use of temporary bus pull-outs during construction are being discussed to reduce the delays to traffic caused by stopped busses. 12 ..,. ~ ,~-. ~,,, Preferred project alternative: Roadwav Recommendations: The preferred roadway akemative is to replace the asphalt pavement along Broadway with a new concrete pavement with an "astroturP' carpet dragged finish identical to the surfacing type used in the previous concrete reconstruction between Regent and Universdy. The reconstructed pavement section will maintain histoncal lane widths which wdl require a variance from CDOT and FHWA. By maintaining histonc lane widths, the sidewalk widths would not be encroached upon and adjacent trees would not be impacted. Improvements to the pedestrian facilities in the corridor and to the Boulder Creek are part of the recommended altemative. Bridae Recommendations: After studying both rehabilitation and replacement options for the Broadway Bridge over Boulder Creek, it is recommended that the bridge be replaced with a new structure. See Appendix B for Plan Views and sketches of the bridge altematives. The new design will not reqwre modification to the ditch headgate located in Central Park or permanent impacts to the patio located near the Southeast comer of the bndge. There will be temporary impacts to the patio during construction in order to complete ~ excavation and construction of the south abutment. Reasons for Bridge Recommendation: 1 Rehabilitation of the existing structure would be extremely difficult. There is a high degree of uncertamty that the bndge can be rehabilitated without caus~ng significant damage to the fascia beams and bndge rail. (See Appendix A describing the details of the rehabilitation option). 2. The addition of a secondary crash railing located adjacent to the existing rading could potentially compromise the histoncal integrity of the bridge. 3. A second bridge would need to be constructed north of the existmg bridge to meet pro~ect needs related to flooding and operation of the Boulder Creek Path. This bndge would increase the impacts to the park during and after construction. 4. The rehabilitation option improves the flood carrying capacity of the bndge but does not allow for easdy increasing this capacity in the future. 5. The replacement option increases the flood capacity and can be easily modified to further increase this capaaty in the future. 6 Cost of the rehabilitation option is difficult to estimate due to the urnque nature of the work. Our best estimate at this time is that this option would cost $700,000 to $1,000,000 more than the replacement altemative. ~ 13 7. Use of modem materials will allow the new structure to have a slender and sfeek design as it spans the creek. 8. A new bridge will meet current design codes, safety requ~rements and have a lower life cycle cost (reduced maintenance). The rehabifitation option will continue to require a high degree of maintenance on the rail and fascia beam due to the inadequacies in its original design. See Appendix E for additional details and pians for the recommended project altemative. Public input to date: ~ The planning and public involvement actiwties for the Broadway Reconstruction pro~ect began last spnng with an intemal staff and agency stakeholder meeting held on Apnl 20, 2001 and then the first public open-house meeting held on May 17, 2001. The purpose of these meetings was to review the project issues and to obtain comment as a part of the issues identification for the pro~ect. The second series of stakeholder and open-house meetings were held on July 13 and July 24 respectively. The purpose of these meetmgs was to gain feedback on the bridge altematives, conceptual roadway and streetscape design, proposed Bouider Creek Path improvements at the crossing of Broadway, and to tollow-up on the issues that were raised at the first meetings. See ~ Appendix F for the comments received at these meetings. Staff established several lines of communication with the commurnty for this project. A pro~ect webpage was created and is updated as new mformation is produced. Questions and feedback are received via this site. The project phoneline was created and provides updated information and the opportunity to leave a comment or question about the project. The first project newsletter was distnbuted in early July to interested citizens and orgarnzations as well as residents and property owners in the area bounded by Euclid Avenue, 9"' Street, North Street, and 17~'!20"' Streets. This is the same mading group and area that receroe the invitations to the public open-house meetings and numbers over 7,000. Staff made pro~ect presentations to the Hillside, Mapleton Hill, Whittier and University Hill neighborhood associations. Project presentations and updates also have been made to such locat organizations such as Downtown Boulder Inc., Historic Boulder, PLAN Boulder, BBC and the Boulder ETC network. See Appendix F for the comments received via phone, mail, web or at the neighborhood or local organization meetmgs. Planning and coordination with other affected entdies such as utiliry and ditch companies, neighbofiood organizations, and private property owners have begun and wdl contmue throughout the project design and construction. ^'~m ia - ~ The Broadway (State Highway 93) Bndge is owned and maintained by the Colorado Department of Transportation (CDO~. The Broadway Bridge is generally considered eligible for the National Register of Historic Places. A Histonc Building Inventory Record for the bridge was prepared in 1995. The bridge has not been formally submitted for a determination of eligibility for the National Register. The Carter-Burgess consultant team is conducting Section 106 and 4(~ Reviews, which are the Federal processes to consider actions on historic structures. This process provides the public and histonc preservation communiry with the opportunity to comment on Federally funded pro~ects pnor to implementation. Staff and the consultant team met with the LPAB at their May, June and July meetmgs to get their input on the draft listing for the historic resources survey report and the bridge altematives. Staff will seek the LPAB's recommendation on the CEAP this fall. Staff wdl also present the CEAP for consideration by the Downtown Design Advisory Board (DDAB), the Parks and Recreation Advisory Board (PRAB), and ultimately the Transportation Advisory Board (TAB) prior to consideration by City Council. Staff project manager: Alex May, Pro~ect Manager Noreen Walsh, Project Planner ~ Other consultants or relevant contacts: Carter & Burgess (Project Manager) Carter & Burgess (Enwronmental) - Love & Associates (Floodplain Hydraulics) - Hermsen Consultants (Historic Properties)- Transplan Associates (Traffic)- Shapins & Assoc (Landscape/ Urban Design) Moser & Associates - Clanton & Associates (Lighting) - Goals Assessment: George Tsiouvaras Gina McAfee David Love/Nancy Donner Gail Keeley Bill Fo~Steve Tuttle Jerry Shapins/Kim Douglas Rick Moser Nancy Clanton 1. Using the BVCP, describe the primary city goals that the project will help to achieve: General Community Design Facilities and Services Environment Economy Transportation ,~^` '~.,, i s ~ Housing ~.~ Social Concerns and Human Services The Broadway Reconstruct~on Project addresses the pnmary BVCP goals of Transportation, Community Design and Environment. The Transportation goal supports an integrated, all-mode transportation system that is safe and convenient for ali users. Broadway is one of the north-south multi-modal corndors identified in the city's Transportation Master Plan. The Transportation goai supports road system improvements in order to protect previous investments and ensure the efficient use of the road system. The street, path and bndge reconstruction components will support this goal. The BVCP goal of Community Design supports improved design of individual urban areas, rural areas and the region through design features such as efficient multi-modal corridors. During planning and design of the Broadway Reconstruction Project, many streetscape improvements for pedestnans, bicyciists and bus users have been identified. These improvements will likely be implemented in a phased approach. Staff will construct as many of these improvements dunng the 2002 construction pro~ect as the budget wd{ allow. Staff will attempt to find addrtional fundmg sources to implement the remaining items that are not constructed in 2002. The Community Design goal supports the Central Area (downtown business district, the unroersity and the crossroads-area ,••-~ regional commercial district) as the regional service center of the Boulder Valley. ..~ The Broadway Reconstruction Pro~ect wili make needed pavement and bridge repairs, improvements and upgrades that wdl improve mobdity on one of the major north-south corridors accessing the Centcal Area. The Community Design goal supports tree conservation efforts and the Broadway Reconstruction Project addresses this by workmg with the City Forester to save existing heafthy trees in the area and to identify new trees in focations where there is not one, or the existmg tree is m poor condition. The proposed roadway width also allows for the presenration of many trees. The Community Design goal supports designs which provide accessibility to those with limited mobility and provide coordinated faalities for pedestrians, bicyclists, and bus nders. The Broadway Reconstruction Project addresses this issue by improvmg curb access ramps at all intersection comers, correcting the extreme roadway cross slopes which will also improve access for mobility-impaired and etderly individuals, upgrading bus stops and pedestnan facdities and widenmg the Boulder Creek Path under the Broadway Bridge. The Community Design goal also suppor[s that new capital pro~ects are positive additions to the community's architectural and urban design heritage. To that end, staff has been working with representatives from the DDAB, LPAB and city staff during the plannmg and design of the project and will seek their recommendation on the CEAP. -~. is ~ The BVCP Environment goai supports the assessment of a pro~ect's environmental impacts. The Broadway Reconstruction Pro~ect is being reviewed under the local Community Environmental Assessment Process (CEAP) and the federal Section 106 and 4(f) processes for assessment of environmental impacts on communiry resources. The Enwronment goal supports the protection of water quality, and the project will incorporate a trial instaliation of a sediment collection system on the local storm sewer system to be improved wdhin the corridor. The Broadway Reconstruction Project will include a Best Management Practice (BMP) for stormwater runoff to Boulder Creek, east of the Broadway Bridge. The Enwronment goal supports flood management with the functional and aesthetic qualities of drainage courses and waterways being preserved and enhanced. The reconstructed Broadway Bridge over Boulder Creek will have mcreased hydraulic capaaty to handle ma~or storm events but the project is not making any further structural improvements to affect the functional and aesthetic qualities of Boulder Creek. The Environment goal supports the use of recycle materials. The base for portions of the street reconstruction of Broadway will be compnsed of the original recycled asphalt pavement material. 2. What are the trade-offs in terms of city policies and goals? ,,r, One of the main trade-offs and impacts of the Broadway Reconstruction Project is the removal and replacement of the Broadway Bridge over Boulder Creek. Preservation of Histoncal and Cultural Resources is a sub goal of the Community Design goal in the BVCP. The Broadway (State Highway 93) Bndge is owned and mamtained by the Colorado Department of Transportation (CDO'n. As part of CDOT's capital improvement planning, the structural condition of the bridge was ident'rfied in the 1980s as being structurally deficient and the bndge continues to be one of the lowest rated on-system structures in CDOT Region 4. The Broadway Bridge is generally considered eligible for the National Register of Histonc Places. An extensive analysis was undertaken to determine whether the ex~sting bndge could be rehabditated. A number of altematives for the bridge were looked at, including no action to rehabilitation to reconstruction. After a complete analysis of these altematives iYs recommended to reconstruct the bndge, and as such, the existing bridge will be removed and replaced with a reconstructed bridge. The new reconstructed design will carry forth many of the onginal design features of the existing bndge, but m a modem context and presentation. 3. Is this project referenced in a master plan? If so, what is the coniext in terms of goals, objectives, larger system plans, etc.? If not, why noi? ~ Broadway is identrfied in the Denver Regional Councd of Govemments (DRCOG) t7 long-range Regionai Transportation Plan (RTP). The Broadway Reconstruction Project is identified in the ciry's Transportation Master Plan. Broadway is ident'rfied as one of the c'ity's major north-south multi- modal corridors. The project supports the TMP's goals of providing an integrated, muiti-modal transpoRation system and maintaining the exisiing street facility in a good condition since it is the prinapal infrastructure for each of the modes. 4. How wil/ the project exceed city, state, or federal standards and regulafions? The roadway horizontai and vertical geometry will meet applicable standards. The pro~ect wiil retain the existing lane widths which wiil not comply with state and federal standards. During project planrnng, staff and its consultants examined the histoncal accident data and did not find any conclusive evidence that the existing lane widths resulted m a safety hazard or higher than normal accident potential. Staff will be seeking state and federal variance from the lane width standard. .~,,, The design of the new bridge will convey the 100-year storm flood flows that are r~~, confined to the creek. Side channel flood fiows m Canyon and Arapahoe wi~l r..~ continue to impact the area floodplain. The new bndge will meet requirements of the City's Floodplain Development critena, and will also be designed to withstand the structural forces of a greater than 100-year storm event in accordance with federal criteria. Impact Assessment Using the attached checkiist, identify the pofential impacts ot the proposed project or (if applicable) ihe project alternatives: ~8 Community and Environmental Assessment Process Checklist Project title: Broadway Reconstruction ~ a E ~~.r ~ « a A. Natural Areas 1. Disturbance to speaes, communities, habdat, ecosystems~ X B. Riparian Areas/Fioodplains 1 Encroachment upon the 100-year, conveyance or high hazard flood zones~ X 2 Disturbance to or fragmentation of a npanan corndor'~ X ~;g"~-r ~ - `~"7'~"i,as° ~,_";-,~"- ~iu2'^;,°,« -i;~-~°„<~,wrs,Ny.n°^ Ah'sf'e.~*~;l'~,e"ii~'~ ~: x` t-~'~~,p ~ "s'~ . ' zr~+, ='-~`~~"+,y ,.'`~~;,,=,{, a",~. ~v~`: t`-eSy` -,".~"~~.;s~~^$Y:3+=~° :=.~v~.t",'~"~.,~.~:'".,_~;.u.s»:~:~.~.~.y-.;3tx;%asm~a.'„~i'a^~:.~.e...,- C. Wetlands 1. Disturbance to or loss of a wetland on site~ X ~~°^~ti~-~; _~ ~- ~ ~ ~ -,~~;~F~,„-~ ~,- ,. ~.~_._k ~' F w~+, x; ~ , ~~' ~ ~ " r ~;~ -`~k-- '~. a~rk , '' x^ '~~k~*i`~* ~''~;~ ~' " ' ' ° . ~, ~ F r ~ „ k ~ ~ ~ ~ ~ uz'~ .._.,v_2~'~' `~..:~:`.~`.,U w u' T.w-, _ ~iru~:2~.^,.. mxi..._ ~`;,,;~ a D. Geology and Soils 1 a. Impacts to urnque geologic or physical features~ O b Geologic development constraints~ O c Substantial changes m topography~ X ~,, .- M1~y^~" ~_ _~~ ;,'~x-~~~"~=` -_~q-,a,=,~,z~~_,L,.M_,_ s t ~" t~~ ~ = ` , ~ . .~ ~ . . ~ _ . ~_ ~ ~~.~~..``~_.a._ _. „ ~~ .. ~° - ~ ~_.,M~a,~,=_ . ,. ~ E. Water Quality ~r 1 Impacts to groundwater or stormwater quality~ X 2 Discharges to the stormwater or sanitary sewer system~ X 3 Potential impacts to streams, ditches, or other water bodies~ X 4 Groundwater contamination on site~ Minor potential X ' ~ "~' 4' " "`r , "r: ^ ti Y • ~ ' ~ - ~ „_ ~-„-~.,Y.a. ~...-~..'".;........~'._~,,._ ",.v..,.,,~ ..........s-,.F...._.. ......~ ..... _ ,. -.. - ,-,,.s ... -.~ _ F. Air ~uality 1. Impacts to air quality~ X n... :~, s ~ 4 ~ ~ ~ n _.._~_ ~-a~„= ~~. ~ ,~..vw_ ,~..~_ _.~_, ~-- =-,-~_,_~,_ . v~..,..,.~~, _ . ~.,~.~ G. Resource Conservation 1 Chanaes in water use~ X 2 Increases m energy use~ O 3 Generation of excess waste~ O _~, ~,,. ,.~ o~,- ~a__ ~..,~~~;~x~r^. _~,~. .~ _ ~;.~~m.~,~i- ` r:. ,,- ,' ° '` 1M ~ ~ `,-~ ,~ m~~ ~, ~~~~,~.rir~ ~ ~ ;~ v ' _N r~ ~~ , ;,, ;~ ~~: _ ~. .~+.~~*~s~,~ ~: , ~~ :. ~. .~~~ xu ,~a-~~ ~~~ . H. CultureVHistoric Resources 1.a. Impacts to a prehistonc or archaeological sde~ O b. Impacts to a bwlding or structure over frfty years of age~ X c Impacts to a histonc feature of the site~ X d. Impacts to sigrnficant agncultural land? O _.~.~ ~ ~ a„~„-~„ ~~^ , s~~ ~- r~-.,...-:...~-;,~~..,~, ~ .~,fl~~-,w-..rR,-., . ° t~ k~j ai~Y~ ~u~~ ~ S. y _ ~ o- . ~ ~ ~ ' ' " ~ ~.;.~~.,~`~ ~.~:s. ..~.....o,t.~..v,,,..rr~,:~=r.:~ ,.,..;.o,::~s.. 1i~3 ~.ar a'S,~zzf `__ _.._~~~ ~.-__,.~w.,~a:,~*:3.7 I. Visual Quality 1 a. Effects on scenic wstas or public views? Blend m posdwe effect. X ~ X = Applicable 0 = Not Applieable Community and Environmental Assessment Process Checklist b. Effects on the aesthetics of a site open to public view? X c. Effects on ~news to urnque geologic or physical features~ O "^~ . n ~-^'--~~>x4,a<ti'?,Y',~:~~»~-~ : - _ _„.~.~,_z .~ ~<_v._. ~ M.__~u~.~__4~~;-~~.:~~~~~~`~.~.._~~._~y.." . ~.~~",=`'N= J. Safetv 1 Health hazards, odors, or radoM X 2 S~te hazards~ Dunng construcUon pro~ect pub. wiCTC 8 bamers X .. _ , ~. . _=ir":'t~"asss"rx.-~`:`."+.~','=^~'.~.~,`-~': "~'-~#.~°~"'»-°F'~ie._. %-"?'ai' ;~.. 'x~ ~~+-,t.~,-'v nr*~. : . K. Physiological WefMbeing 1. Exposure to excessrve noise~ X 2 Excess~ve I~ght or glare? X 3. Increase in vibrations~ X - ~, __ _,.-,m4.K--_~m ,__ . ;, ...~ z -...>_...~...._ _..,._~.:.i.<~.~6:;~~'9_ ~, .,t., ~~ ~r`~"~`t~..t+5ix~;,i'_.:...:•Y":x.~`..,'s=;,`~+"`~:r~:~"`~z~ s L. Services 1. AddRional need for. a health care/social services~ O b sanitary sewer services~ O c police services~ O d fve protection~ O e recreation or parks faalities~ O f libraries~ O g transportat~on improvementsRraffic mitigation~ O h parking~ O i affordable housing~ O ~ open space/urban open land~ O _ k power or energy use~ O I telecommunications~ M. Special Populations ~ ' ~ ~ ~- ~ ~ O ~ a persons wdh disabilities~ x-slope roadway~mp Ramps X b. sernor population~ X c children~ Safer sidewalks X d. restncted income persons~ O e", ^'*1 X = Applieable 0 = Not App{ieable ~ Community and Environmental Assessment Process ~ -Checklist Questions- Note: The following quest~ons are a supplement to the CEAP checklist. Only those questions ind~cated on the checklist are to be answered in full. A. NaturalAreas a. b. c. d. e. f. .~- g. `~... h. Describe the potential for disturbance to or loss of significant species, plant communities, wildlife habitats, or ecosystems via any of the activities listed below. (Significant species include any species listed or proposed to be listed as rare, threatened or endangered on federal, state, county lists.) Construction activities Vegetation removal Human or domestic animal encroachment Chemical pollutants (inNuding fertilizers, pesticides, herbicides) Behavioral displacement of wildlife species (due to noise from use activities) Introduction of non-native plant species in the site landscaping Hydrologic alteration (groundwater, surface runof`~ Increased sedimentation in any body of water The nparian corridor along Boulder Creek at Broadway is characterized by mature trees and a dense understory, which provides important wildlife habitat. Removal of some of the mature trees and nparian shrubs in the immediate wcinity of the bridge dunng construction will result m habitat loss and displacement of wildlife species. Loss of vegetation may affect species such as raccoon, possums, small mammals, and song birds. The area was assessed for potential threatened and endangered speaes habitat, in particular, Preble's meadow jumping mouse, Ute ladies'-tresses orchid and Colorado buttertly plant, three federally-threatened species that occur in riparian and wetland areas. This reach of Bouider Creek does not provide suitable habitat for these three species because of the surrounding urbanization and lack of extensive wetland vegetation. No threatened or endangered species or other species of special concem are expected to be adversely affected by the proposed pro~ect. The Project Team is awaiting Fish and Wildlife Service concurrence. Dunng construction, there may be increased sedimentation into Boulder Creek. Increased sedimentation will affect the aquatic fauna such as native fish and ~ game fish including brown and rainbow trout. The pro~ect will use Best ~.., is Management Practices to help prevent excessive sedimentation, and an Erosion Controi Plan wtll be developed for construction. .~., B. Riparian areas and Floodplains Describe the extent ta which the project wi/I encroach upon the 100- year, conveyance or high hazard flood zones. The section of the project on Broadway between Arapahoe and Canyon is already tocated withm the high hazard zone. Improvements to the Boulder Creek bridge will improve the flood conveyance of the bndge from the current 10-year event to a bridge that is built to convey the portions of the 100-year storm that is within the main channel. A City of Boulder Floodp{ain Development Permit will be applied for this project. 2. Describe the extent fo which the project will encroach upon, disturb, or fragment a riparian corridor. The ripanan corridor is already fragmented by the existing bndge and the width has been truncated by urban development. Construction of the bridge will affect some ripar~an vegetation in its immediate area, which would increase the area of disturbance slightly, however, fragmentation of the nparian corndor would not mcrease significantly. ,...~ C. Wetlands 1. Describe any disturbance to or loss of a wetland on site that will result from fhe project Road improvements will not result in the permanent loss of wetlands, adopted and regulated by the City. See Appendix G to wew Wetlands Map. Due to the proposed lengihenmg of the bridge, a slightry wider channet in the immediate vicinity of the bridge will result. The bndge construction will require temporary excavations and bridge construction supports around and within close proximity to the existing bridge. This is reqwred to allow for construction of the new bndge. Construction wdl require the use of heavy eqwpment on and around the bridge. Impacts related to construction are temporary. Palustrine forested and scrub/shrub broad-leaved deciduous wetlands are present adjacent to Boulder Creek and the Boulder and Left-Hand Irngation Ditch. Total wetland acreage within the project area is approximately 0.761 hectare (0.398 acre). Dunng construction activities at the bndge, approximately 0.002 hectare (0.004 acre) of wetlands on Boulder Creek streambanks will be temporarily impacted (based on a 6.1 meter [20 foot] wide construction zone adjacent to the existing bridge structure). IVo permanent wetland impacts are ,.,~ ~ 20 anticipated. An application for a City of Boulder Wetland Permrt wiil be submitted ~ ~, for this project. ~.. Consultation wdh the U. S. Army Corps of Engineers is antiapated once the impacts associated with bridge construction have been determined. All disturbed wetland and buffer areas will be restored. Restoration will include seeding, planting, and/or sprigging with appropriate, natroe vegetation to meet the requirements of applicable permits. D. Geology and soils 1. Describe any: a. Impacts to unique geologic or physical features? No. b. Geologic development constraints or etfects to earth conditions or landslide, erosion, or subsidence? No. c. Substantial changes in topography? The pro~ect generally follows the existing profile from Canyon to Pine. Slight ~ profde adjustments (on the order of 1 foot or less) have been made to improve specific pro~ect deficienaes. The ad~ustments mclude ad~ustment to the profde from University to Marine by less than one foot. The ad~ustment will expedite construction through the corndor by recyclmg the existing pavement in place, thus not reqwring excavation of the existing roadway section. The benefit of this is that it better matches the profile of the ex~sting sidewalk (currently timber retaining walls are located adjacent to trees to make up the grade difference). The other roadway profde ad~ustment is a raising of Broadway by approximately one foot between Arapahoe and Canyon to increase the hydraulic opernng for the bridge over Boulder Creek. The Boulder Creek path realignment under the new bridge will also require regrading of path approaches. E. Water ~uality 1. Describe potential impacts io groundwater or stormwater quality that may result from the project. During construction temporary impacts may occur with open excavation along the project. The contractor will be required to adhere to an erosion control ~ 21 plan. Storm sewer construction will include a trial installation of a sediment collection system wrthin the project limrts. ...~ 2. Describe poieniial increases in stormwater discharges thai may result fiom the project. The pro~ect will improve existing drainage inlets and include improvements to tfie storm sewer system between Marine and Arapahoe and between Walnut and Boulder Creek. This improved storm sewer (Marine - Arapahoe) will outfall at Boulder Creek downstream of the Arapahoe bridge. These upgrades are a part of the Stormwater Collection System Master Plan and wdl provide for improved and controlled conveyance of 5-year storm flows that currently overtop surrounding areas flowing uncontro~led into Bouider Creek. 3. Describe pofential water qua/ity impacis to streams, ditches and other water bodies from the project Some erosion may occur during construction and m tandem with a storm event. The contractor will be reqwred to adhere to an erosion control plan. 4. Is there a likelihood of gioundwater contamination from past history on the sife or an adjacent site? It is unlikely that construction activities will result in groundwater ...,, contamination. ~. A Modified Phase I Environmental Site Assessment (ESA) of the Broadway Reconstruction Pro~ect corndor along Broadway between Pine Street and University Avenue in Boulder, Colorado was completed. The assessment was pertormed in order to evaluate the potential for encountering hazardous matenals or impacted soil along the project corridor dunng construction. The Modified Phase I ESA was performed in general conformance with the scope and limitations of ASTM Standard Practice E 1527 but was modified to account for the project being confined to a narrow, linear corndor restricted to the right of way of Broadway. The conclusions are that at the time of this Modified Phase I ESA, the property in the proposed area of construction is a low environmental nsk because no hazardous matenals or impacted soil are expected to be encountered as a resuft of construction activities associated with the project (there are no suspected or known environmental concems which would warrant further investigation), This conclusion is based on the understanding that the majority of the excavation will be restricted to the existing "curb-to- curb° width of Broadway, with the exception of curb and sidewalk improvements and tie-ins at intersechons, and that excavation for resurfacing .., 22 wdl be relatively shallow (1-2 feet). Excavation for the bridge storrn sewers ~ and utilities would be deeper but would remain within the limits of Broadway, with the exception of a storm sewer outfall located along Arapahoe Road and flowing mto Boulder Creek. These conclusions and recommendations have been based on a limited inspection and research of public documents pertaining to the sub~ect property. Copies of this report can be provided for review. F. Air Quality 1. Describe potential impacts to air quality resulting from this project. Distinguish beiween impacts from mobile sources (VMT/trips) and stationary sources (APEN, HAPS). The project wdl not increase capacity along Broadway and no permanent ~mpacts to air qualrty are anticipated. Some temporary deterioration m air quality can be anticipated due to construction activities. G. Resource Conservation 1. Describe potential changes in water use that will result from the project. a. Esiimate ihe indoor, outdoor (irrigation) and total daily water use for ~, the facility. b. Describe plans for minimizing water use on the site. (Xeriscape landscaping, efficieni irrigation system) Yes. New medians and some addition of curb-s~de irrigation wdl increase water use. The pro~ect will use a drip system where possible and result m minimal mcreases in water usage. 2. Describe potential increases in energy use that may result from ihe project. a. Describe plans for minimizing energy use on the project or how energy conservation measures will be incorporated inio the building design. Refer to the 2000 International Energy Conservation Code. None. 3. Describe the potential for excess waste generation resulting from the project Describe plans for recycling and waste minimization (deconsiruction, reuse, recycling, green points). ~ None. 23 H. CulturaUHistoric Resources " ~ 1. Desciibe any impacts to: a. A prehistoric or historic archaeological site. b. A building or struciure over fifty years of age. c. A hisioric feafure of fhe siie such as an irrigafion ditch. d. Significant agricu/tural lands. The pro~ect wdl lead to adverse impacts to at least one resource considered eiigible to the IVationaf Reg~ster of Histonc Places, the Broadway Bridge. See the discussion of bndge aftematives in Section 2 of this document. Adverse effects determined by the SHPO may also be made for the trolley tracks that are located on Broadway. At this time, prelim~nary field assessment of the trolley tracks' impact is that it will not be determined to be an adverse impact. Archaelogical assessments are undervvay by CDOT. 1. Visual Quality 1. Describe any effecis on: a. Scenic vistas or views open to the public. ~, b. The aesthetics of a site open to public view. -.- c. View corridors from the site to unique geologic or physical feafures, The new bndge proposed at Boulder Creek will provide a clear span structure which wdl allow the visrtors of Central Park to view both sides of the park. This wdl improve the visual connection at the park and prowde a positive experience for park patrons Safety 1. Describe any addiiional health hazards, odors, or exposure of people to radon that may result from the project. None. 2. Describe any additional site hazards that may result from ihe project. (Including risk of explosion or the release of hazardous su6stances such as oil, pesticides, chemicals or radiation) No During construction the contractor will be reqwred to provide construction traffic control, temporary barriers and fences to protect the public. The contractor will also be reqwred to meet OSHA regulations to safely facilitate construction. P., 2a ~ K. Physiological Well-being 1. Describe the potential for exposure of people to excessive noise caused by any phase of the project During construction, construction equipment including excavators, drilling ngs and other heavy equipment wdl result in temporary noise impacts, but wdl meet ciry code reqwrements. Permanent noise impacts are not anticipated, and this analysis is included in Appendix H. 2. Describe any excessive light or glare that may result from the project. The pro~ect may require some periodic night time work including: major mtersection reconstructions at Arapahoe and Canyon and Bndge Reconstruction. Night time work could require the use of portable lighting units. 3. Describe any increase in vibrations that may result hom ihe project. The use of heavy eqwpment including concrete trucks, dnlling eqwpment, excavators, dozers and pawng equipment could result in temporary vibration impacts. L. Services ~ 1. Descri6e any additional need for the following services as a result of the project: a. Health care/social services b. Water or sanitary sewer services c. Police services d. Fire protection e. Recreation or parks facilities f. Libraries g. Transportation improvements/traffic mitigation h. Parking i. Affordable housing j. Open space/urban open land k. Power or energy use 1. Telecommunications None. 2. Describe any impacts to any of the above existing or planned city services or department master plans as a result of ihis projecf. (e.g, budget, available parking, p/anned use of the site, public access, automobile/pedestrian conflicts, ~ views). zs None. A permanent reduction of 2 parking spaces is anticipated with the .-.,3 construction of mtersection improvements at the southeast comer of Walnut and ,,.. Broadway. Temporary parking restrictions are anticipated. Adequate public access within the corridor will be maintained during the majority of the construction. Sidewaik, neckdowns and other pedestnan related improvements wili improve safety in the corndor. M. Special Populations 1. Describe any etfects the project may have on the following special populations: a. Persons with disabilities b. Senior population c. Children d. Restricted income persons This pro~ect wiil benefit all of the above populations. The roadway cross-siopes wdl improve and provide ADA compliance for street crossings. Sidewalks and curb access ramps wdl be improved in many areas Access to the Boulder Creek trail system will be improved with a 22' wide path under the bridge and improved „y hydrauhc pertorrnance of the bridge will mitigate trad closure dunng spnng run-off 4j~ ' and other storm events. ATTACHMENTS Appendix A- Techrncal Memo on Bridge Rehabilitation Altemative Appendix B- Bndge Design Concepts Appendix C- Streetscape Concepts and Existing Condition Analysis Appendix D - Traffic Analysis Appendix E- Preliminary Pro~ect Design Drawings Appendix F- Public Input To Date Appendix G - Wetlands Map Appendix H - Noise Analysis J LTrensportaLOn\0703634nanage~coMCEAPReport doc 26