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HomeMy WebLinkAbout3B - CEAP Flood Protection Levee Reconstruction and Improvements Bear Canyon Creek-Foothills ParkwayCITY OF BOULDER INFORMATION ITEM FOR: TRANSPORTATION ADVISORY BOARD WATER RESOURCES ADVISORY BOARD PLANNING BOARD PARKS AND RECREATION ADVISORY BOARD OPEN SPACE BOARD OF TRUSTEES ENVIRONMENTAL ADVISORY BOARD DO NOT REMOVE - PRAB File Matenal GREENWAYS ADVISORY COMMITTEE AGENDA ITEM WATER RESOURCES ADVISORY BOARD AGENDA ITEM MEETING DATE: May 2002 ~~ r~" ~... SUBJECT: Community and Environmental Assessment Process (CEAP) Flood Protection Levee Reconstruction and Improvements Beaz Can on Creek - Foothills Parkwa to Ara ahoe Avenue REQUESTING DEPARTMENT: Public Works Department - Uhlrties Division Ned Williams, Assistant Duector of Public Works for Utilities Bob Hazberg, Utilities Pro~ects Coordinator Anne Noble, Greenways Coordinator BOARD ACTION REQUESTED: Staff requests boazd members to review and provide comments on the CEAP, and requests the Water Resources Advisory Board (WRAB) and the Greenways Advisory Committee (GAC) to consider a roval of the CEAP at their meetin s m Ma 2002 Purpose• Information Item and Agenda Item for WRAB and GAC Staff is requestmg boazd members to review the CEAP and provide comments to your Greenways Advisory Comm~ttee representahve or Nancy Stemberger at (303) 441-4111 The Water Resources Advisory Boazd and the Greenways Advisory Comm~ttee meetings m May 2002 will mclude public heazmgs and considerahon of the CEAP for approval Backsround• The proposed pro~ect mvolves reconstrucring and improving the existmg flood protectron levee along Beaz Canyon Creek between Foottulls Pazkway and Arapahoe Avenue. Components of the project mclude extending the length of the levee to mcrease the capture of flood waters, raising the height of the levee to meet the current FEMA standards for freeboard, plantmg the levee wrth natrve grasses and shrubs, selective debris removal from the stream channel, water qualrty BMPs, emironmental restorahon, and habrtat preservanon of the stream corridor. A future phase of this pro~ect may mclude excavatron within the west overbank (m the grassy azea between Foothills Pazkway and the Open Space property) to increase flood conveyance The center segment of the levee, which pazallels the north-south stretch of Hamson Avenue, will be improved by adding structural backfill and riprap covered by topsoil to increase the height and will have a 3-foot top width to accommodate a footpath The segments at the upstream and j°"~" downstream ends of the levee will use a structural concrete flood wall in combination with a `"` nprap levee covered by topsoil. Selective debns thinning and environmental enhancements will be coordinated with city Open Space staff The levee project is located along Bear Canyon Creek between Foothills Parkway and Arapahoe Avenue, although environmental enhancements may extend upstream of Foothills Pazkway. Analvsis• Critical deficiencies have been identified in the existing flood protection levee for the Willowndge Pazk Subdivision, located along Harrison Avenue immediately east of Bear Canyon Creek Dunng a recently updated study of the Beaz Canyon Creek floodplain, prepared by Love and Associates, Inc under a city of Boulder contract, the existing levee was found to be out of compliance with current FEMA standazds for freeboazd. The levee was also found to have vulnerabilities to flooding which include low crest elevations subject to possible overtopping and inadequate length subject to possible flooding azound the upstream and downstream ends Due to these Identified deficiencies, the consultant was obliged to omtt the flood protection levee from the updated floodplain study. As a result, the Beaz Canyon Creek floodplain in this area without the flood protection levee would be stgnificantly Increased and would adversely impact as many as 42 residential structures containing 58 sepazate dwelling units. Without the levee the conveyance zone spreads to the northeast, impacting the Wlllowridge neighborhood and the Boulder Community Hospital site. The purpose of the proposed project is to reconstruct and ~ Improve the existing levee to function more effectively, to meet current FEMA standazds and to ,,,,~ provide envirotvnental enhancements of the stream comdor This project was included in the 2002 CIP for the Flood Utility and the Greenways Program, and was referenced In the Annexation Agreement for the Boulder Community Hospital development approved by Ctty Council The Open Space Board of Trustees has approved the disposition of approximately 22,000 square feet of the Hatch Open Space property for the purpose of reconstructing, improving, and maintaining the flood protecUOn levee Action Requested: Staff requests board members to review and provide comments on the CEAP and requests the Water Resources Advisory Board and the Greenways Advisory Committee to consider approval of the CEAP for the flood protection levee reconstruction and improvements for Bear Canyon Creek between Foothills Parkway and Arapahoe Avenue Attachment: Community and Environmental Assessment Process (CEAP) Flood Protection Levee Reconstruction and Improvements Bear Canyon Creek -Foothills Parkway to Arapahoe Avenue ~"'^ COMMUNITY AND ENVIRONMENTAL ASSESSMENT PROCESS `,., Flood Protection Levee Reconstruction and Improvements Bear Canyou Creek -Foothills Parkway to Arapahoe Avenue Apnl 11, 2002 1. Description and location of the project: The proposed project involves reconstructing and improving the existing flood protection levee along Beaz Canyon Creek between Foothills Pazkway and Arapahoe Avenue. Components of the protect include extending the length of the levee to increase the capture of flood waters, razsmg the height of the levee to meet the current FEMA standazds for freeboazd, planting the levee with native grasses and shrubs, selective debns removal from the stream channel, water qualrty Best Management Practices (BMPs), environmental restoration, and habitat preservation of the stream comdor A future phase of this project may include excavation within the west overbank (m the grassy azea between Foothills Pazkway and the Open Space property) to increase flood conveyance The center segment of the levee, which pazallels the north-south stretch of Hamson Avenue, will be improved by adding structural backfill and nprap covered by topsoil to increase the height, ,,,., and will have a 3-foot top width to accommodate a footpath The segments at the upstream and downstream ends of the levee will use a structural concrete flood wall in combrnation with a nprap levee covered by topsoil Selective debns thinning and environmental enhancements will be coordinated with city Open Space staff The levee project is located along Bear Canyon Creek between Foothills Parkway and Arapahoe Avenue, although environmental enhancements may extend upstream of Foothills Parkway (see Vicinity Map) 2. Background, purpose and need for the project: Cntical deficiencies have been identified in the existing flood protection levee for the Willowndge Pazk Subdivision, located along Han•ison Avenue rmmediately east of Bear Canyon Creek Dunng a recently updated study of the Beaz Canyon Creek floodplam, prepazed by Love and Associates, Inc. under a city of Boulder contract, the existing levee was found to be out of compliance with current FEMA standazds for freeboazd. The levee was also found to have vulnerab~hties to flooding which include low crest elevations subject to possible overtopping and inadequate length subject to possible flooding azound the upstream and downstream ends Due to these identified deficiencies, the consultant was obliged to omit the flood protection levee from the updated floodplar study. As a result, the Beaz Canyon Creek floodplam m this area without the flood protection levee would be significantly increased and would adversely tmpact as many as 42 residential structures containing 58 sepazate dwelling units. Without the levee the conveyance zone spreads to the northeast, impacting the Willowndge neighborhood and the "" Boulder Community Hospital site. The purpose of the proposed project is to reconstruct and improve the existing levee to function more effectively, to meet current FEMA standazds and to provide environmental enhancements of the stream comdor. The existing flood protection levee was constructed in 1977 as part of the Willowndge Pazk Subdivts~on development A floodplan development permit was issued May 5, 1977, to "construct a structure m the Floodway to prevent Beaz Canyon Creek flood flow from entenng Willowndge Subdivision" and was generally described as a flood protection dike Additional staff correspondence pertaining to the 1977 permit also indicated that construction of the 47~' Street -Foothills Highway "should require that the complete highway plan include excavation of a 100-yeaz capacity channel adjacent to the highway." Subsequent highway construction completed m 1979 did not include the recommended dramageway improvements, leaving the Hamson Avenue berm as the only flood protection for the Willowridge neighborhood. A future phase of the currently proposed project may include excavation within the west overbank (m the grassy azea between Foothills Pazkway and the Open Space property) to increase flood conveyance Although levees aze not currently regazded as the most progressive floodplain management approach, this technique avoids impacts to the stream comdor that would result from increasing the conveyance of the creek In addition, the existing levee rs included on the adopted Flood Insurance Rate Map (FIRM) but has critical deficiencies, therefore repairs aze needed. ,^ This project was included m the 2002 CIP for the Flood Utility and the Greenways Program, and was referenced m the Annexation Agreement for the Boulder Communtty Hospital development approved by Crty Council The Open Space Boazd of Trustees has approved the disposition of approximately 22,000 square feet of the Hatch Open Space property for the purpose of reconstructing, improving, and maintaining the flood protection levee 3. Description of project alternatives and summary of major issues: Three alternatwes were evaluated for addressing the deficiencies in the existing flood protection levee These included a) Re-map the floodplain omitting the existing levee. This was rejected for several reasons. First, omitting the existing levee is a modeling scenano, not a physical reality, since the current berm does exist although rt does not meet the standazds of a flood protection levee. Second, in the model that omtts the levee, the conveyance zone spreads to the northeast, impacting the Willowndge neighborhood and the Boulder Community Hospttal site The existing berm would impede this conveyance zone shift to some degree, and the actual conveyance zone would depend on the location of berm 2 _ failure. Third, as many as 42 residential structures containing 58 sepazate dwelling amts ~W.. would enter the Special Hazazd Area on the FIRM. b) Excavate the Bear Canyon Creek channel to increase the capacity of the drainageway. This was rejected due to the environmental impacts associated with channelization, recognizing that the ma~onty of the impacts would occur on city of Boulder Open Space property. Modified components of this altemative were incorporated into the proposed project. Selective debris removal is being proposed as part of the project to improve habitat value and reduce blockage of the stream channel. Excavation within the west overbank (in the grassy azea between Foothills Pazkway and the Open Space property) may be considered as a future phase of the project to rncreae flood conveyance capacity. c) Reconstruct and improve the existing flood protection levee. This is the selected alternative. The proposed project will meet the objective of providing flood protection for the Wtllowridge neighborhood and prevent the shift in the conveyance zone which would impact the neighborhood and the Boulder Community Hospital site. Although levees aze not currently regazded as the most progressive floodplazn management approach, this technique avoids impacts to the stream comdor that would result from increasing the conveyance of the creek. In addition, the existing levee ~s included on the adopted FIRM but has cntical deficiencies; therefore, repairs aze needed Components of the project include extending the length of the levee to increase the capture of flood waters, raising the height of the levee to meet the current FEMA standazds for freeboard, planting the levee with native grasses and shrubs, selective debns removal from the stream channel, water ~. quality BMPs, environmental restoration, and habitat preservation of the stream corridor A future phase of this project may include excavation within the west overbank (m the grassy area between Foothills Pazkway and the Open Space property) to increase flood conveyance 4. Public input to date: There has been public input on the CIP, the Boulder Community Hospital site development, and the disposition of the Open Space land for the reconstruction, improvement and maintenance of the levee In addition, the neighbors aze being asked for input regazdmg the final design, alignment, and the landscaping of the levee at a neighborhood meeting on April 18, 2002 5. Staff project manager: The Engineering Project Manager for this project is Nancy Stemberger. 6. Other consultants or relevant contacts: The consultant on this project rs Drexel, Barrell and Company - civil engineering, hydraulic modeling, levee design o... ..,~ Goals Assessment: ®_ 1. Using the BVCP, describe the primary city goals that the project will help to achieve: General The goal of the project is to mitigate flooding by reconstructing and improving the existing flood protection levee along Bear Canyon Creek to function more effectively, to meet current FEMA standazds and to provide environmental enhancements of the stream comdor Community Design The levee is not proposed to be a community design feature There will be improvements made to the landscaping by using native species in the revegetation plan, and the environmental enhancements will contribute to community design goals. Facilities and Services The proposed project improves an existing flood control facility and includes environmental enhancement of the stream comdor Environment ^, The project will include environmental enhancement of the Beaz Canyon Creek comdor rr m the project area Specific improvements include planting the levee with native grasses and shrubs, selective debris removal from the stream channel, water quality BMPs, environmental restoration, and habitat preservation Economy The project will provide flood mitigation to protect residential and commercial properties, and will prevent the shift in the conveyance zone which would impact the Boulder Community Hospital site. Transportation The proposed project will not effect transportation. The reconstructed levee will include a 3-foot top width to accommodate a footpath. Housing The project will provide flood mitigation to protect existing residential structures. Social Concerns and Human Services The project will prevent the shift in the conveyance zone which would impact the 4 Boulder Community Hospital site. 2. What are the trade-offs in terms of city policies and goals? Current floodplain policies embrace non-structural approaches to floodplain management which accommodate floods but do not attempt to control or contain them. Although levees are not currently regarded as the most progressive floodplain management approach, this technique avoids impacts to the stream corridor that would result from increasing the conveyance of the creek In addition, the existing levee is included on the adopted FIRM but has critical deficiencies; therefore, repairs aze needed The project goal is to reconstruct and improve the existing levee to function more effectively and to meet current FEMA standards, and to provide environmental enhancements of the stream corridor. 3. Is this project referenced in a master plan? If so, what is the context in terms of goals, objectives, larger system plans, etc.? If not, why not? This project is referenced in the Greenways Master Plan In terms of goals, objectives and lazger system plans, this project meets multiple objectives of the Greenways Program including stormwater and flood mitigation, habitat preservation and water quality enhancement 4. How will the project exceed city, state, or federal standards and regulations? The prolect will meet or exceed all standazds and regulations In particular, the project will ~- reconstruct and improve the existing levee which is included on the adopted FIRM but has critical deficiencies The project goal is to reconstruct and improve the exisring levee to function more effecrively, to meet current FEMA standazds and to provide environmental enhancements of the stream comdor Impact Assessment 1. Using the attached checklist, identify the potential impacts of the proposed project or (if applicable) the project alternatives: ~~•. °w COMMUNITY AND ENVIRONMENTAL ASSESSMENT PROCESS -CHECKLIST "`~ Flood Protection Levee Reconstruction and Improvements Bear Canyon Creek -Foothills Parkway to Arapahoe Avenue Note The following questions are a supplement to the CEAP checklist Only those questions indicated on the checklist are answered rn full A. Natural Areas Descnbe the potential for disturbance to or loss of significant: species, plant coinmumhes, wildlife habitats, or ecosystems via any of the activities fisted below. (Significant species include any species listed or proposed to be listed as raze, threatened or endangered on federal, state, county fists) -SEE BELOW a construction activities b vegetation removal c human or domestic animal encroachment d chemical pollutants (including fertilizers, pesticides, herbicides) e behavioral displacement of wildlife species (due to noise from use activities) ~ f introduction ofnon-native plant species m the site landscaping ,,,,,„_ g. hydrologic alteration (groundwater, surface runoff) h increased sedimentation m any body of water If potential impacts have been identified, please provide the following A description of how the proposed project would avoid, minimize, or mitigate identified impacts. -SEE BELOW A habitat assessment of the site, mcluding• 1 a fist of plant and animal species and plant communities of special concern found on the site, 2. a wildlife habitat evaluation of the site. -SEE BELOW Maps of the site showing the location of any Boulder Valley Natural Ecosystem, Boulder County Environmental Conservation Area, or cntical wildlife habitat - NOT APPLICABLE a. The project involves construction activities on the existing levee, which is located 40-feet to 200-feet east of the stream channel Heary equipment will be used, although the noises and potential disturbance will be similaz to that associated with traffic on neazby Foothills 6 '°"~~ Pazkway Potential is low for disturbance to or loss of significant species, plant communities, `'" wildlife habitats, or ecosystems via construction activities. b. Some vegetation, including trees, will be removed to accommodate the levee reconstruction and improvements Non-natives, primarily crack willow, will be removed, while native trees and shrubs will be avoided to the extent practical. The levee will be replanted with native grasses and shrubs. c. It is not expected that drsturbance from humans and domestic animals will increase as a result of the project. d Chemical pollutants will not be part of the protect. Maintenance of the vegetation after protect completion will be performed by selective mechanical removal of noxious weeds, with limited use of herbicides. If herbicides are selected for control, only chemicals certified for use near streams wtll be used. e Due to the location of the protect neaz Foothills Pazkway and residential yazds, tt is likely that the resident species include tolerant urban generalists which aze not sensitive to noise or other human disturbances Therefore the potential is low for behavioral displacement of wildlife species f Only native vegetation will be used in site landscaping. g. Hydrologic alteration will be part of the protect, since the primary purpose is to mitigate flooding h Sedimentation will not be increased Selective debris removal from the stream channel and water quality BMPs will reduce sedimentation to the stream ,, _, B. Riparian areas/floodplains Describe the extent to which the protect will encroach upon the 100-year, conveyance or high hazard flood zones - SEE BEt,ow 2 Describe the extent to which the protect will encroach upon, disturb, or fragment a riparian con•idor - SEE BEt,ow If potential impacts Gave been identified, please provide the following A descnptron of how the proposed protect would avoid, minimize, or mitigate identified impacts - SEE BEt.ow A map showing the location of any streams, ditches and other water bodies on or neaz the piOJeCt Slte -SEE ATTACHED A map showing the location of the 100-yeaz flood, conveyance, and high hazazd flood zones relative to the project site -SEE ATTACHED ~~^^ ~'~r The proposed project lies primanly within the 100-yeaz floodplatn, but also encroaches into the "'Oi high hazard and conveyance zones of Beaz Canyon Creek. The purpose of the project is to "'° provide flood mitigation by reconstructing and improving the existing levee to function more effectively, to meet current FEMA standards and to provide environmental enhancements of the stream comdor. This project is within the ripanan comdor for Beaz Canyon Creek, and is partially located on crty of Boulder Open Space property. A Greenways Ripanan Habitat Assessment was conducted dunng the summer of 1999. This assessment evaluated the quality of nparian habitat along Boulder Creek and all of its tnbutanes through the city of Boulder, including Beaz Canyon Creek. Ratings were determined for the structure of the vegetation, the amount of native vegetative species and the vaziety of bird species present. This project encompasses BCC Reach 1 of the Ripanan Habitat Assessment. In this reach the ranking for native plant species was poor, but the vegetative structure ranking was good The aquatic habitat ranking was fair. No data was reported for this reach for bird species richness. This project will not compromise the quality of the npanan habitat and in fact may improve the stream corridor by planting the levee with native grasses and shrubs, selective debris removal from the stream channel, water quality BMPs, environmental restoration, and habitat preservation In addition, the levee may provide a bamer to separate the riparian habitat from the roadway and adjacent residential uses C. Wetlands Descnbe any disturbance to or loss of a wetland on site which will result from the~,,,1 project -SEE BELOW If potential impacts have been identified, please provide the following A descnption of how the proposed project would avoid, minimize, or mitigate identified impacts. -SEE BELOW A map showing the location of any wetlands on or near the site Identify both those wetlands which aze jurisdictional under crty code (on the wetlands map in our ordinance) and other wetlands pursuant to federal cntena (definitional). -SEE ATTACHED The proposed project is pnmazily within the wetland buffer, but will encroach into city of Boulder regulatory wetland No 7 due to the lengthening of the levee to the south and the environmental enhancements. The quality of the existing wetland azea is medmm, as rt contains some of the only forested wetlands along Bear Canyon Creek in the city One of the goals of the proposed project is to improve wildlife habitat and water quality. Impacts to wetlands will be avoided where possible and minimized in azeas where impacts aze unavoidable The mitigation efforts will be on-sue and m-kind, and will meet or exceed the city's regulatory requirement of 8 ^""* w''°°' 2.1. The protect also serves as a restoration effort, therefore considerable effort will be devoted ~"' to removing non-native vegetation, native plantings, and improvement of the functiomng of the wetland and riparian azea as wildlife habitat. D. Geology and soils Describe any a impacts to unique geologic or physical features b. geologic development constraints or effects to earth conditions or landslide, erosion, or subsidence c substantial changes in topography wkuch will result from the project. - SEE BELOW The project will not impact any geologic or phystcal features except for the extension of the levee and the increase m levee height. E. Water Quality Describe potential impacts to groundwater or stonnwater quality which may result from the project - No IMPACTS ~~ 2 Descnbe potential increases in stonnwater d~schazges which may result from the protect - No IMencTs Descnbe potenttal water quality impacts to streams, ditches and other water bodies from the protect - No IMPACTS Is there a likelihood of groundwater contamination from past history on the site or an adjacent site? - No IMPACTS The completed protect will improve water quality by including environmental enhancements such as selective debris removal from the channel and water quality BMPs Stormwater conveyance will be improved by prov~dmg flood mrt~gation There will be no additional impervious azea as a result of the project. Construction activities neaz stream channels have the potential to impact water quality Best Management Practices (City of Boulder Wetlands Guidelines) wtll be followed to m~mmize impacts. ~,"' r..- .•w No contaminated groundwater rmpacts have been rdentified at the srte. '~' Air Quality Descnbe potentral impacts to air quality resulting from this project. Distinguish between rmpacts from mobile sources (VMT/trips) and stationary sources (APEN, HAPS) - No IMPACTS The protect wrll not have any rmpact on air quality G. Resource Conservation Describe potentral changes rn water use which may result from the project - No IMPACTS a Estimate the rndoor, outdoor (rmgatron) and total daily water use for the facrlity b Descnbe plans for mimmizmg water use on the srte Descnbe potential increases m energy use whrch may result from the protect - NOIMPACTS ^~ v a Descnbe plans for minrmrzrng energy use on the protect or how energy conservation measures wrll be incorporated into the building desrgn Describe the potentral for excess waste generation resulting from the project. Descnbe plans for recycling and waste minrmization (deconstruction, reuse, recycling, green points). - No IMPACTS The protect will not use water or energy, or generate waste Inrtrally, plantings wrll need to be watered to ensure establrshment and survrval. Plantrngs wrll be selected and located based on the water requrrements of the plant and the srte conditions to mrmmrze the need for continued watering H. Cultural/Historic Resources Descnbe any rmpacts to a. a prehistoric or historic archaeologrcal srte. b a buildrng or structure over fifty years of age c. a historic feature of the srte such as an rmgatron ditch 10 ° °~ !'' d. significant agricultural lands L which may result from the project - No ImrncTs The project will not impact any cultural or lustonc resources. Two abandoned concrete irrigation features exist east of Foothills Pazkway, north of the current Wellman Ditch The project will avoid these structures. I. Visual Quality Describe any effects on. a. Scenic vistas or views open to the public. b The aesthetics of a site open to public view c. View comdors from the site to unique geologic or physical features which may result from the project -SEE BELOW The project will increase the height of the existing flood protection levee, therefore there may be a small impact on scenic views or view corridors The view from the footpath on top of the levee will improve as a result of the increase m levee height The aesthetics of the site will be • considered during final design to minimize impacts J. Safety Describe any additional health hazards, odors, or exposure of people to radon that may result from the project - No IrvtencTs Describe any additional site hazards that may result from the project. (Including risk of explosion or the release of hazazdous substances such as oil, pesticides, chemicals or radiation) - No IMPACTS The proposed project will improve safety by providing flood mitigation There will be no addrt~onal health hazards, odors, exposure to radon, or increased site hazards as a result of the project K. Physiological Well-being Describe the potential for exposure of people to excessive noise caused by any phase of the project. -SEE BELOW r^ 11 ~... 2 Describe any excessive light or glare that may result from the project - No "'~` IMPACTS `~ Descnbe any increase to vibrations that may result from the project. - No IMPACTS If potential impacts have been identified, please provide the following: A descnption of how the proposed project would avord, minimize, or mitigate identified impacts. -SEE BELOW During construction, nose related to heavy equipment operation will be generated during the daytime hours No other phase of the project will have a negative impact on physiologic well being L. Services Descnbe any additional need for the following services as a result of the project - NOIMPACTS a health caze/social services b water or sanitary sewer services ,~, c police services .,,~ d fire protection e recreation or parks facilities f libranes g transportation improvements/traffic mitigation h. pazking ~ affordable housing j open space/urban open land k. power or energy use 1 telecommunications The proposed project will not increase the need for any of the above services or fac~l~ties. Descnbe any tmpacts to any of the above existing or planned city services or department master plans as a result of this project (e g budget, available pazking, planned use of the site, public access, automobile/pedestnan conflicts, views) - NOIMPACTS There will be no impacts to any of the above ex~shng or planned city services or department master plans as a result of this project. 12 ""'* ~`"' M. Special Populations 1. Describe any effects the project may have on the following special populations - NO IMPACTS a. persons with disabilities b senior population c. children d restricted income persons There will be no impacts to special populations as a result of this project ~- 13 Community and Environmental Assessment Process Checklist Project title: Flood Protection Levee Reconstruction and Improvements ~ a E a~- A a ...,, a m .~ > m a p A m w E E d r ~d.. a a a A. Natural Areas 1 Disturbance to species, communities, habitat, ecosystems Y N Y B. Riparian Areas/Floodplains 1 Encroachment upon the 100-year, conveyance or high hazard flood zones Y N Y 2 Disturbance to or fragmentation of a riparian corndor~ Y N Y C. Wetlands 1 Disturbance to or loss of a wetland on sites Y N Y - - D. Geology and Soils 1 a Impacts to unique geologic or physical features __ _ N _ _ N Y _ _ b __Geologic development constraints _ _ N N__ N c Substantial changes in topography N N Y .-Y,r. n., w .~~?CaC^ dw " a. p.. , _ .. _ ~_ _-~~_ . "~o-~mY ~e=It~M^'t,'^..1°Cil&}i5`^'=°~§~; r ® ~~ _~ <~ `~,}"' x,~t tu`,5_~irPix,°v. °~ ,i °~', f.: _ s`.~-.-., =;~':r....~~'.'<~1:.::..r'. =`ueas`m'c~`.`.~`s,~i°`tt°-` ;.~`".,„' r~ E. Water Quality __ _ _ 1 Impacts to groundwater or stormwater quality _ _ 2 Discharges to the stormwater or sanitary sewer system 3 Potential impacts to streams,_ditches, or other water bodies _ 4 Groundwater contamination on site - ...:itii'~m'F~ 'TI "i=3 - ~`t "S ^_".fli~3M~"`° b:1 T'rTY £rr v~ ua-~--.-,...=m~-C -~ -=ny ~~`~;r rn L~~~„u_ "~ kKti~=~ i'~~ sz~"`g":sa+'iam`,, -<,°y ~~;,r„~' _ " - __,_ .h ~.: co. '='~,t"u _ S__p,..y„y..__ti ~__ •'azv``T3:''.3~"y~"~T°r am ~~li~. F. Air Quality 1 Impacts to air quality -= ~=~~z`5 3fi,, ,~,y;,,,~„~;n - n~-~a, -, ~,.~ ~s_m~~xr-a~ce,'~,c'~.'~'?Yt""' `__'."~,._`~o"=e'-b.`_;'.`:z~..7"?'-.,.. - -_<_'~~u~'E""'~E~~• 4~~."w<'.': ~`.„~$`.~ 7... _ __ ".i ~ __ ,.»..~n `3=~'- _ =:~t?~= `6~"'c`k6>su,.7.d#k~*.~`M~~'..`:v"t'F. _ G Resource Conservation N_ _ N N _ ~, N N N N _N__ _ Y _ N N N N N N 1 Changes in water uses N N N 2 Increases m energy uses _ _ _ __ _ _ _ N N N 3 Generation of excess wastes N N N 1P-? " ' ` ~ " ' '~.~` ~'~ = F' ''~i ' ~ ' ' ~i} ~ ~ ° u 's:_ __ .'^e =. Ac mS+53i:. ~_nYrAYafb~a [+, _~i J i}c'ii'... ' ' ~ ...n mmwa .+.:u °°c ~J a y ~ w Z `. _ _ _ _ __ _ H. CulturallHistoric Resources _ _ 1 a Impacts to a prehistoric or archaeological sites _ N _ N N b Impacts to a b_wlding or structure over fifty years of age? N _ N _ N c Impacts to a historic feature of the sites N N N d Impacts to significant agricultural lands N N N I. Visual 1 a Effe vistas or public views Page 1 N N N Y =Applicable N =Not Applicable Community and Environmental Assessment Process Checklist b Effects on the aesthetics of a site open to public viev/~ N N N c Effects on wews to unique geologic or physical features? N N N J. Safety 1 Health hazards, odors, or radon N N _N 2 Site hazards N N N ~~ ,~„~, K. Physiological Well-being 1 Exposure to excessive noises N N N 2 Excessnre light or glares N N _ N __ 3 Increase in wbrations~ N N N s^ °~ ' _ _ , u L. Services 1 Additional need for _ a health care/social services N N N b sanitary sewer services _ N N _ _ N police services c N_ N N _ d fire protections _ _ N N _ N _ e recreation or parks facdities~ _ ___ N N_ _ N f libraries N N N g_ transportation improvements/traffic mdigation~ _ _ N N _ N h parking~ __ _ N N N __ affordable housings i N N N _ _ _ _ - _ _ _ ~_ open space/urban open lands _ N N - - N k power or energy uses _ _ N N N I telecommumcations~ N N N a,~ :"`-t"v ''36~+ Syt~" [{ S ~a"C r`: € -f~'t~ ~Skh ~i~ td ~ ~ ~ ~ ' °~' = .~ . . ~ . i a, .. . 1 .«.,-._ , ., l - . a. u , M Special Populations _ _ __ 1 Effects on a persons with disabddies~ _ _ N N_ N _ _b senior populations ____ N _ N_ N c children N N N d restricted income persons N N N Y =Applicable Page 2 N =Not Applicable VIQNITY MAP - -- - - - - - ~- o- -. ~i.., ~~ ._ ~ ~ f ~ n~ - ~ ~ ~ ~ q1 ~~.-.rte _ _ _ - _ - .- _ _ _- - . ,- ., - ,, ~ r ~~. S _ _ ~ ._- ___ - _ ~ / a i ~ ~ ~- / _~ - _-• __ - a-. ~ ' ~-~ ~ .-- -~_ - _ _ __~ -_ ~ _ _ __ ~~ -_ - ~ ~ . __ -- - ~- J~~~ i ~ < _,~ _~ _-+Ci i Y ~ ' ~ ~t ~ '. I -__ _ _ - - .. ~ ~ ' ---. - I -- -- - l ti ~j y _ _ i x - - t--` _- a ~~ _ r -~t_ ~ ~ ~ ~ ~ _..~ __ ___ + - - -- _ - ~ ~_.~ -- N __ _ Site Location - . -- \ --~-- ~ n - -- - ~ =~ Arapahoe Ave- --- - ~ .~ -- , ; -~ _ - - . - ,~,,.0 - - v , -- ~ '~ ~ ~~ - it ~ - ~~ ~ ~~ ~, .~,' ~~' _ , `,- - - __ ~_ LEGEND Main Roads NMenal ~~~ ./~ yA ) ~ NHigtaVay ~/ MapLmk - Street Centerlines Cily of Boulder Survey Polygons -- Lakes Q City Limits ° ... ~ , ~ ~ _. -- _ ~~, ,, !' - ~_ , -- N 2 Miles `°<, " .. ~"~"'_;.~es`'l n :h `i .., `~„~ ».....,___` ~ rte.,.:.-_ ~ `a ~ s - ^;` vJ ... "%`,. \tx._ _ i~^Ly,\ek~'%k,_'``..~i t.~ ''~_3-s,~l~ IT __- i.-. ~ -~ tti~C~<+`a^-~. ..c ~"`i ..4Ry'k ~`i A~44* 1~' ~~ ~ i 1~1/ ~ ~a t -~-I l~ ~' V''cy. °yiy Y`~ ~~~.A'T V' i§'. I L-__ ~__ 1 I \ ~ ~ P 1 ~ I 4 ~ t~.•~r~4~``ih . k ~^' .ya .~I~ `. 'piers .'.p i 1-~ ~ `~ Y \`e s «r~ -~ ~~ ~~ ,.» ~~.~' , r,' _.~: ,~~ __ r_ ,i, ~-~. ,~~~ ~; - ~~~ I~ ~ -I',*r ~J ~ ~ ~ t. T ~ ~I =C _ ! <~ _ SITE' - - ~~~ ~., ,~ I ~ ~, - - ~j 4~ ~ n`+*` ~ / ~- \1\ 1' FF I(~[~~~7 rrl r``b~ V ~p•~1 ~ ~ ~ ~~ rT ~ oa ®~®,® ®_® _ E URORA AVE - fT1 fT1 IT1 !-'1 ~~ LEGEND 500 0 500 High haz.shp Conveyshp 100year.shp i ;n ~. i ~u ~~ EOITM ( ~ ~; I ~~~ ~' O I'. - - _ t i~ , -~ `~r~i ti ~~ ~ - C _ j- ~ , y 1 P ~`~- ~T r f L _ lJ f N _ 3 - _p- - -\/ -- _ - ~- 1; - o ." ~ _ _ ~ ~ `~ C~ _ ~~ y~ ,~, - c,y - ~ -~ '~ ~ ~ ~~ ~~ t0 S - it ~ (~ i Q MepLlnk Cary d Boulder GIS ~~a~,.a~v,.~ya a>s ~1.~.~ wy rdm~aa,~,m~r. ~~ ~~~~ Wetlands Map P W I ~ ~ ~ _ - - - -I- r r' o T- _ _ \ _ _ ~ r-' ... - ~ -_ ~ --- T ~~ ~ ~, ~ ; - Q ,~ s' - -_ o~ - _ F~ d ~ _--_ "" ~ - \ -- Lev ~ ~ ~, ~ ! v_ - ~_, - ~ ~ ~ _ - SITE, _ ~ ~ _ - - - - - _ ~~ - s _ ~ ~ - ~o~av qq~ - '- - -~ - --- _ ~ - _- ~ ~ ~ _ _ = t_ - - = 3-_'~ - -- - _ __ - ~r Q -.--~ rc, ~~ - gyp- - ~~ i __ _ _-- O .. ! --- __ - - - --~ ~ _ - _ ~ s = - .~- ~ - a~ A~ ~ r~ ~ cs ~ _. ~o ®~®®®~~ ~~~- - - ~ ~ -~ ~_ I o - r - _ -- __ ® ~ ~ 3 - ~ ~ " `~ ~~~ - - ~ " ~ ~~ ~~ _ g~ __ - _ - _ ~ -'t ~ ~ > k - - _ .~ v - ~ PS - O _ ^ f~ tin ~ ~6 LEGEND ~ ~~:~rt BuJd"g Fmprvm ° ~"` 500 0 500 Feet - '- Tank ~ a~ N^n^w Nor .:~,~n~ Swwv PU4yun o.n,„nv Pxe4 c~yt.ao Q MapLmk Cary of Boultler GIS n.mf~d~,m~~~wo m~ aigeaedmieplyd, m~he ~^r+'Y md/acampkrercxddag vdwrmum cnmamad6vmn. 11° LAYER OF O5p=6" RIPRAP OVER 12" TYPE II BEDDING COVER RIPRAP VATH 4" OF NATIVE TOP SOIL AND SEED MATH NATIVE SEED MIX 3 w 3 ~ ~ 1 1 ~ o(l ,~. ,` ~ EXISTING GROUND ~ \ ~ SELECT BACKFlLL APPROVED BY GEOTECHNICAL ENGINEER. COMPACTED TO 95R STANDARD PROCTOR m LEVEE IMPROVEMENT -TYPE A NO SCALE 10" ;~a o 1e^ o c N PROPOSED GRADE-SEE PLAN ` ~ O ~t \ \ PROPOSED GRADE-SEE PLAN p /R5018`OC~~ J \ 1 ~ O CONCRETE \ O FLOOD WALL 11" LAYER OF Dsp=6" RIPRAP OVER 12" TYPE II BEDDING ~ ~ COVER RIPRAP WITH 4" OF \ NATIVE TOP SOIL AND SEED O WITH NATIVE SEED MIX ~ 10' 10" ~ \ Q ~ TOP OF FOOTER \ ~Q• :rte/i //i /\ / / OO OO 2 - N 0 ~~/ O~/~~o~~ /\\\/ (I`Q ~OOD r • " o SELAPPROVEDFl Y /\\ OO OO GEOTECHNICAL ENGINEER \~~\~ •~ ~ •, SELECT BACKFlLL STANDARD PROCTOR APPROVED BY y//\/ ~/~\~/\\~//\/~~~ GEOTECHNICAL ENGINEER. BOTTOM OF FOOTER ~\ \~\\\/ COMPACTED TO 95x STANDARD PROCTOR 14" f0" 6" 18" LEVEE IMPROVEMENT -TYPE B NO SCALE ~ ' \ ~ ~-~ / ~ ~ 5244 8 ~~ ~~ / ~' / 5246 5 ~ /~ 5253 0 .~'~' /( ~ I /J / ~ ~J / ~ \ 5243 4 ~ \ 5242 9 5240 8 N ,~ ~ Zh/ 5247 ~' 246 2 524 5 \ 5 5~~02406 ~ Regulatory Flood Map SKU EE \s E A O 52 9r ~\ ~ EE _ E F ~O ~L REV/S/ S T /S 1 / ~ ~.~~ ~ ~ ~ o ~ K ...~4 6'.. REq. \ CONFLU NC sz37 s 5 ~ 3 ~ "~• O 414 \\5241 1 SKUNK CR ro / 52}6 ~+ t •.. B `~ e ~~ ` 52449 \ A 52 95 52364 ~ \ 5240 6 239 7 52 8 ~ / \ X71 O S~ 52464 ` , ~ 52430 5241 0 \ ^ 52397 •~U\ so ~~5 ~ ~~ ` ~~~ ~ ~ ~~ 3 ~~ \ ~~.~~~ ~~\ ` O'f \ 25 35 2 5235 6 5235 I ~ \ \ ~ 390 ~ ~ ~ i`6 ~ p •/ \ 5 5 5 BOULDER CR K 5 6 523 5P39 2 236 9 i o X2672 52607 sz45,~L~°LA/N ~~~ ~ - ~ 2 \ ~ ~~ 5240 5 ~ 523 \ \ ~• 523 I 5244 6 \ 5232 \ 5259 1 2 8 ~ /1 2 3 7~ 6 6 2 92 5241 37 I - v 1dl%qD OI/IA ~IMP6ld 4 ~ D rPClurod Frot-~ 52367 _ Z ~l T /~-S'R ~-T. _t~ ~ 52354 s F{OO p/0/n 5z 6 / High Hazard Zone e 6 _ szs 0 5231 5 f6 \52 ~ 2 2 ~5~ ~ Conveyance Zone 6241 0 1 52 32 5 i~ 5 / °0 1 \~ ~~ / ~' x+'523 4 74 5 4 _ 260 4 '- 5 3~4~ 5238 ~~ D~ ns Trees ~ ~~~~ 52636 \ 52 5 3~ 8D Eor ~ p 5232 3 5231 1 ~-~ 5 42 2 C~> p ~/ sz4 .a ~ ~ w5 rngN 4rz / 260 5251 I (gyp ~ 7J ~ N r+~ ~ v 373 52346 ~ ~ Ar 1 n p 1,1~~1~ 2 / D ~ m~ 52457 ~ 52451 1 5 52331 \ Nd ~ ~ 1 ri 5 4 ~\ ~ 5249g 4~ ~ 5 2 7 2 56 1 ~v 5~.~\> / 5235 5 613 ~ ~~~~ 253 l ( / 5 42 2 2675 ~ ~l/ S?S \\\/// / ~~ ~ e~ef e~ l~ 5262 / D ~'1 ~ ~ // GG G~ i:( / ~7 v 23 I / 52 59 0 ~ 1 - 26~~L, /00-YEAR SHALLOW FLOOD/NG AREA ~ ~ N ,034 59ft ~ r~ (DepJA = /~J ~, 54,283 36tt v ~t ELEV 5 63 42ff ~ ~, 111 100-Year Flood lain Z THE FLOODPLAIN DELIMEATION8 and FLOOD PROFIT `1•I 1 p I 1 n ~ ON Tii18 8MEET ARE BA8ED ON FLOOQPLAIN DATA ~ ~~ ~ D VELOPED A3 A PART OF THE FL DD INBUR 52666 HgN000K Urc~~ 0 8~UDY FOR THE CITY OF BOULDER, PT WHERE N( 1111111~~ t~ `---~'~ ~ - - - - --- - -- -- -- - - - - -- ------ ---- - - -- --- - ----- -- --- - ---- - - - - --- - _ _ PLAN AND ROPIL _FRO _ SE TION _ _ _ ___ -- _ - _ - - - - -- - - T 1986 - - - - - -- - - ...; - - - - - - - - - - ---- - 8~ - r..= ,., m, High Hazard Zone High Hazard Zone .~ Existing Flood Conditions (model omits the berm) ~ ~ ~~~ sra>F Hwr~ ----- ---'---~- - 47s sus I _ _ i~ - `~;3 ."' -"--- -- - _ ___ _ _ _____ __!~_ -- - - ~ o EdN83.19 IMPROVEl1ENT5~ I I ~'tAF N 'SEE SHEETS LV2 AND LYS _" _ +szaol d _ ,I, I TART Flfi(1 WAI I FOR LEVEE CRO55-SECnONS - i x 11 I I ~ - - ~ v sEE Lva Fdt TWICAL SECnoNS. _ \ \ ~ I PAM6 A I ~SL95 _ '~ ~ s1J5> -_ -- - I REC1 N4 1t1Na40 1 / - s _ ~__ _ \ O .11 ROPOSED VEE ___ ` / _ _ ~ - _ GNMENT _ _ _ _. - -- - __ _ - v v +szms ~ ~ 1~' I I V L A- __ 4sxrm I ~ - ~ ~/ 1 I _e Sz.^' ~pOQ~D E705TNG Z-18" dAP \ V °1 \ WLVERTS 10 LF O 05R ~ r e cut tlaz - ~ ~P _ , IN 1B' ALUMINUM FLAP R6a BxexlB AEC. NB 4emu \ - ~ -- = r _ I z.la., R __ _ ~ SATE ENDS OF 18 CMP ~i ~ ~ ~ F _~ WATERMAN A 1 1 AR APPROVED, I (~ v- ~' ~ i - ~ ~i ~ I I ~,.. - }5z45i Il EWAL' x N~ i A. 5+7 22 ., c% ,, .~,` Is3JD7T'__"~-' _ .( l"`l ` ~ ~~ I ~ ~ " ' Ih I I y ~ 1 . /,. -. I I N 950818 ~~_ -I.szros ,-j `~ 4'~ ' I E 1267 ~ - - ~-.SL --, 14 I I ^.~ \ - , ~ II _ WALL ~. / -_-' ~, I _I _ ~ ~ ' IN 9485 1 '- d I ,t - . r,l~ , ,1~~2 . _ __~_ ~-r-~ _ I _ _ _ --_ , -~ . E 71289 8 ' WLLBWIIpBE P~„ I -- _'- A I ElW4 xeB -'- _.. _ _ r __ .- ~ I I ~. , ^` ~ - ` - ___ ~ 1 ~ ..- _ __ r _ ;I ,1]C1~7D 5' PVC ~ C - ssr_ 4 _ ~ - ' VQtT W SS ~ J 1 :,+ssra s ' + - - __ _ _ - - _ _ INSTALL 15' MWU GA -- - _ _ _. AT END OF i15 A AN _ / _ -~ ~ d I I ~ - -~ __ we+£ir AF-41 OR EWAL"~ ~1~~ _ _ _ `~ ~ II ~' _ -~~ _ E[ stub i111dc ~ .- -~ -, I . ~ ,_-~~ I' ~!'~ -- ~ 1 I +t N '8251 84' ~ _-' / ` _ / ~ ii ~ r _ I ~ .-~ r ~ r` f _ Ij `1 _ ~ ~ .~ r., _' I 1 -Irt(E'~1}4242-'^d= .~V' .,~ I I I I I I 1/, `, L _ =' i- ADAM LT ~ t J _ ~MtE!` _ '#S2gsB - - LEVEE TABLE STAnON WATER SURFACE TOP OF IEVEE E%ISnNG GROUND ELEVAnON 1+00 523735 5240.35 5238.00 1+50 5238.50 524150 523719 2+00 523848 524248 5238.80 2+50 523991 524291 5238.93 3+00 5240.33 5243.33 5238 ae 3+SD 5240.57 5243.57 573724 4100 524082 524382 523748 4+5D 524108 5244.01 523758 5+00 5241 31 5244 31 5237 80 5150 524180 524480 523822 B+oo u4z.oe sz43oa 5238.m 8+30 524257 3245.37 323&32 7+00 324308 3248.08 323&43 7+50 524355 3248.55 3238.85 8+00 524403 324703 5240,21 8+50 524423 5247 23 5245.10 W00 524434 5247 34 524515 9+50 524448 3247 48 3245.38 10+00 524463 524783 5246.88 10150 5244 78 5247 78 5245.88 11+00 5244.95 524793 524548 11+SD 5243 32 5248.32 3246.80 12400 3245.71 3248.71 324815 12+30 5248.10 324910 5248 85 13+00 5248 49 5248 48 3247 82 13+50 3248 BB 3249 88 5248.95 14100 5247 27 525D 27 5249 97 14150 5247 93 5250 93 5250.75 15+00 524385 525185 525178 1s+so s249n s2s2n szs236 16+00 325089 525389 525250 18+50 525180 575480 575281 n+oD szs2sz szss.52 szsa79 17+50 5253 44 5236 44 525397 18+00 525438 5257 J6 5257 90 18+50 5255.78 525&28 525289 19+00 3255 BB 5258 88 5256 73 19+50 5256 OB 5258 OB 525819 20+00 5256 49 5259 49 525549 20+50 5258 89 5258 89 525838 21+00 5257 2B 5280 29 5259 88 _ - L -^- ___ ~ ._ _ _ ~.= _ _ ____ _:263'-. ' 1 C1 ~ - ~ szsl r _ - -- _- - -- ~ ~ '- J ' i= ~ ~ ' tvn xo t_ I c - IC ~Il~r I +~- I ..-~~` ~ 1 I ~ ' F~ r- ~ L_-.-! `f i I L„_-I '_I 4 ..~L r lil ~ n'I ~~ ' +5250.ji`~_~ ~ , ~ 5_ I ~ 4S i I ` . + I - _ i " • P ,i I ^- ` y A +51416 ~ I q \ __ .. ~ ! ~ Aye I I RR' N I+ I ' I ~ /-~~ _ i/ {~B / 1A ' ' " I 5295 ~ ~ i .- - ~4 ' fi ~.a \:. ~ ~ , R'd_'e- li ~ g 'I f/ Y SI40.1e- _ r~ A/eA / , ~ +5155!'.% 1 - i - I -1 1 1= I \ ~ ^- -- ~ +s14es ~ .I I 9 ._ I I ~ c 'IVi~ ~ _ .- ~ - ~ c ~ ,1 ~ ~._ ~ ,. _ - ~-_ II ~ ~ - ~ ~,' _ -._ -_._ _ Wy ~ ~ ~ ,-- ~ ' I. ' I -_- +s1u9 h ~ ~ I _ I . I I ~_ _ _ ~ I _ -- r I -' - ;I ~ ' - _ _ I _ _ - _ ___ ~ _ IY _ -..I ~ ~ I~II'r ~STy1 G'OIX/A%F-CT +S iez - _ _~, '- _~__' ~- _ ___ __ _ _ ^._^ _ ` I, __ _- -- I -_.__, - --_ N ~^ ~ all ,~ - __ I ' `_ _ __ ,._- - 0 - BEAR CANYON CREIX - ~ Il - CROSS-SECnON ~. _ ~_I 'Ir i wuaWROeE rAMt I/ FlUNO x0.4 ~ - +fS5N8 __ _ ~~ +51-`>' __-_ -- ' _ ' ~_ ~I - _ I I _-_- - -E%IS fING INOE% CONTOUR ~ / IUI - - I ~~ _'' _ '' -J - ~ -EpSTING INTERMEDIATE CONTOUR -- ~ I Ip~ - - -` ~ -- - - . , ~~ _ 7 - 5 ,,~ ._ ,- 15 I ~ ~stJD,MLAS-dFl'~ a 1 _ ~ ~- _ I 835251 N ~ ~~ -~ ~ ' _ _ _ _ SSS E 11F23.74 - '_ _ _-_ WWW222TTT I u v ~0°DW'~` +'E''~'xezza _' ' v 1 i - ~ -~ I ~1 I( I I 1 -- _ _ _ -., -- - _ __ -- - = ' 10o so 0 1oG zoo ' - $ _^ .- -- --- ' __ - SCALE t"-1GO' ,! ~, ~, sTA. 1o-F50 I = ~ _ O, ,y N 7!258.31--='h-__ _ (t X~h'i}Y \ E11M023+'~S=B-HgRR/Sri/-AY£---+ _ _ .` -!______ __- ' - -~._ _ '591-- __ -~ o REc p ~ ~TS~ T _ - _ ~ I nom. STA 79 / - _ • 1 ~ J _ -_= _ +slcrs ~ o a\.^ ov~o.*" f "c - I N 820850 p '_ ' - I 4 ~ - ~ , __ o i ; us 31858 - E114237 V ~ I -- STA. 2G+GG ~ 4 -- .. I __ __ _ - _- _ )~ ~t ~ '~ / - N 8118. 1 # - .....+ E 11483 88 .a.~(4R _ 6T ' ~91"79~ _ J _ _ _ -_6158+ 61+ f A.N ~\,~ WLLOWAWEPMK - -" '" - -'- NOT VALID WRHOUI ORIGINgL R E 156743 \l %i ~ ' FWB N0.3~ -___ ~ - __ -- _ SIGNATURE AND DATE END LEVEE IMPROVFNENTS ~ °' 1 I\ F` ` ' I -~ - - - END FLOODWAL6( \ ~T` - I ~ ~ -- ~ ~ '- BRPMm er _.,. _, Drexel, Barrel! & CO. Engineer surwyar BRnA.m raR BOULDER COMMUNITY HOSPITAL rawBC. xro BOULDER COMMUNITY HOSPITAL ~.~y.-- 4840 PEML EISI CACIE 51"lE 114 ~ BCVrER CO.piABO b]301 I (J0.1) H$-4]]B 1100 BALSNI $1REET I EAST CiAMPUS 517E 8]65 CMPgiA1E BRIVE CLIgfID'J SVWNC$ C0.piApp BGfl19 ~ (T9) $Bo-oml BOUL9ER C0.0RA00 ARAPAHOE AVENUE AT 48TH STREET 1a snH AYFXUE surz z1o C0IJTACT JOHN A EWY P E celrv mLwAOO Boas. aloe 3s+-0645 wrACT MIKE YIXiAN (Sat) 44o-2Sn oazxrm "* Rzvaw xxRwnwz ws wA,WC aFB oArz Jue xo wm PR+ BEAR CANYON CREEK 19 DEC zoot EW-1149 LV1 wI.N BY 1 C` T PRJ LLYLE SGJE w"WN41p. 9EE15 wa«m Bn 1' 100' SD 638 4 BOULDQt, COLORADO JqE v 1' 100' 5250__ _ _ __ - ___ - -_ -_- _ _- __-- _ ___5250 - ----- ---- - STAr 1100 ----- -- - waiMERr - _ 5245 - _ __ _ _ ____ _ ______.____5245 _ - --__ _ __ .-_-_._ _ - .___ _ _ _ _ _T~ OF WALL~524036_____ L40 _ -_ - E705DNG GROUN ,_ 5240 5250 _ _ _ -_ _ _ ___ _ - -_ _ _ - .- -- _5250 - ------ ---- ----- -- -- -- -- ------- - --STAr5t00 -- -- --- '--- - _ wcNMENr -- _ __ _ - - - TOP OF WALL~524431 5245__ _-__ ___ -_ _ ~_ - _____ .__-____ ___ _ _ -__-_____ __ ___5245 - -TOP QF BERM~524231 _._ ____ _- _______ PRWOSED GRADE __ _--_--____---________-___ _ _ 5240 _ E%ISONG GROUND _ _- _-__ _ _ 5240 --5253 __ ___-_____-~_ _ -______ - __--__ ___ __ -_ _ _- _____ - ------ STAr 9100 -- __ -__-_-_ 3255 w MENr - -- - - - ---- - - -~- - 5250 _ _ _ ______ ___-_-_ __ __ -____-_ __ ___- __ ___-__ _ __~____ _ _ _ _ __-5250 _ -___ ___ ___ ___~__.______ _ ___ _. lDP OF-BERMe52Q3;--- -'__,_- _ _ _ _ _____ _ _ _ ____ . ROPOSED GRADE -__ _ - _ _ - -- - 5245 N~CRWND 5245 ~ -_ _ -_-_ ___ ___-____ _ _____~_- ___~__ __- ~ _ __ A ~ __ __ . ~ ___ _ _ _ __ __ __ __ __ -_---_ __ _ ~ - _ _ ___-_-_ _ -___ `_ TOP OF FOOTER~523518 5235 _ _ _ _ _ - _ _ _ 5235 D1'fOM OF FDO lER~5233.52 _ ___ _ ___ _ _ __ _ -__ _-~-___ ___ WIOAI OF_F007~R-527798 5235 - _ - _ _ 5235 - ~ _ ______-_ - ______-_ 3240- -_ _ - _ __ - _ _ _ _ _ __ _- ~~ ~ 5240 ~ ~ ~ - ~ 8230 10C O !OR 5230 5230 2DL fOL O 1LR 2DR 5250 $ ZOL IOL O 11N7 2 /~52~. ,~i 5250 ____ ___- _ '- -" 52-50 - -- STA.- 2100 --- - - --- - - ------ - - - - -- -- -- -- 5255 ~ 5255 - - - - -- -- -- -- - --- -- - --BTA: - 6+00 -- -- -- - - - ------ -- - ----- - -- - --- - --- ---- - ---- --- --- ------- - - -- ----- 5355 - - - - ---- - --- -- --STA.-10+00 -- ---------- --- - ---- AIGN MENr AlTGN MENT ~UGR MFAT-~-- ----- 5245---- ---__---__ - -- _____-- --_- --TOP aF wAUu=sz42ae ----6243 ~ __ 5250----- ---------- ~--- _-,__ - --___ _--_ _-_-_ _ _ - _- -_ ----525b __ ___- _ _-- 5350 --- -- -- -- ---------- - lOP ~ BERIA~5247 B3 --5250 lOP OF BERM~5240.48 .-PROPOSED GRADE __ PROPOSED piADE _~ __--___ - _ _- -_ _ _ - -- - - _- - _ lOP OF_BERM~524&OB ~ --- - _- i i -- _ -_-_ - _~ ~ NC GRWIID fI5D _ 5240_ __ ~ 7oP ~ FOD7ER--,- ~Bl 5240 5245 PROP09ED GRADE 5245 5245 ~ 5245 - -_ _ _ E70511NG IGRWNO _ - ___ _ _ -_ __ _- - - - _ _ - _ _-_ _ ___ „~ ~ -' - --- ~ --_~_-- _ ~ 'OOS7INC GROIRID _ - ~ , ~ 5235._.___________-~____._____OTipA OF FOOTER~S23615___6235 _ _ 5240__..________ __-.___. _-_-__~_______ _.,_-___-_ ________._5240 - 40-___________________~__-.__~_____.____~___________-__-_ _ 5240 5230 JOL O JOR 5230 5235 2DL JOL o 1OR 20R-5235 5335 ZOL fOL b lFJR 20R 5 I , I r I s25D Ta- wU 13t ~ ssau iLBJII s2s5 ,~ , STA.-~f1t0E7 A7UGNMFNI -s24a 33 wAU T~"~ -5245- ~ - . . -.-- 52x5 ~ ~ SOP--0F-BERMsf' 211 33 525iS , 5150 -525th r'T6P-DF-BE1t~=~ 250 cRanF r-lflP f1F RFAM~R74R (NI ~ ' _ PROPOSED CRADE _- -- ~ / _ i PROPOB>) GRADE ~ OSTNC CR OUND 5240 E%IS71NG'CROUND TOP OF FOO7ER-523&85 5240 5245 ~, 5245 5245 _ 245 _ _ _- _--__---_ __ _ '. I ` _ STING GRWND ~- _~ 5235 -_ - - BOTION OF FOO7FR~523700 '5235 40~_ - _ 5240 - -5240 ~ 5240 _ ~~ - - - ~_ ~_ - I , 5230_ lOL O fOR 5230 3- 2DL fOL O 16R 20R 5235 5255 ZO/ IOL O 7OR 20R 52:55 ~ ~ ^ I I ~ I ' i I A-it00 -- I NUGNAIkIII I 325 3A. ~ I I wIRI ' - 8255 Bf00 MW l ~ ~ 8lS5 I STA- ~ wGN ~ ~:'t00 MFNI j - TOP O~LL~62J3.82 -- -- ~ - . STOP aF BERM~5248.71 5245-- _ -_ I 52 TOP OF BETiM~5241 82 5D - 52 ' ------s ^TI1p !1F RFRM..574707 I 5D I ~ 5250 i-PROPOSED GRADE _ _ _ / PROPOSm GRADE _ ~ ~ ~ ~ROPOSID GRADE - ~ ~ S11N0-GROHND 5240 E%IS11NG GRWND TOP OF F007FR- 15 5240 5245 --~ . f 5245 '245 ~ „~ --- p45 ~ L- •• -__ p0 flECi ~ __ 5235 ~ 077011 ~ FGDTEQ-8237 523 _-_ ._ 524D ----~-~ -_5290 __- _ , ~ _ _, _ _J p S __- ox~,R?n~..ri^ 524D ~tp ~~~~ `"*tt o _ = 31869 ti - ___________________ __--- -______--_-___- ,ti 230 JOL ~ 0 70R _,_ 52 0 3235- 2DC _ 1OL 0 fE'R 20R -5235 2 2(7(---- fOC - -~ p -_- ---- I( ' ~ _ ~__ ___ _ __- ___ _ ___ ____ NOT VALID WRHOUT ORIGINPL '- -~- SIGNATURE AND DATE rxwruu en rmu® mrt ssarc+N1R ommrm en R~« ocvxrn«s o.rz wulra Ka 4.1 a,scr _,,~,_ Dreael, Barrell & Co. En4lneen s~rve>o.s BOULDER COMMUNITY HOSPITAL BOULDER COMMUNITY HOSPITAL PRJ BEAR CANYON CREEK i9 Dec zom .~ Psuu EAST ~~. suh ,,. a~ ~,AOO ~~, cm» ,.,_,,,, «.~ m EW-1149 LV -~ esse c«P«AlE omss cuauoo sPauas. caax.m eov,s Na0 e'~w sm¢T EAST CAMPUS SITE 1 c~/~ (ns) xo-ass> gpAppl CClpiMO PRJ LEVEE snit «. No. 9,c[rs e,a >•m ANMIL sxre z,o «mcr cannAOO ms3. (em) as,-au c011TACT NWCE MaNAx (]03) 410-232) ARAPAHOE AVIIJUE AT 48TH STREET wsam cr CROSS-SECTIDN3 ~` is_5, 5D 638 4 CONTACT JdIN A EWY~ PE BOULDER. COLORADO JAE r 1°~S~ l "°=_" Drexel, Harrell & Co ~~ X610 PETAL EI.ST tlRGE NlE 11L BWmER C0.p "... mnwu¢ oRrvx WLCRAW sPwNCS, WLaI o swx Awmc. surz xio mmcr turn. CONTACT JOHN 0. EWY P E 5255-- -_---_____ __ ___- - ---_5255 STA-13100 - __ _ _ __ _ _- _ - _ __ --wGNMENT-__ _ __ - _ __ - __ _ _ _ _ _____ _ -____ _ _ __ _ __TDT! OF BaRM~524948 __ _ _-__ 5250 _ - ___ _ ROPOSm,GRADE___5250 -_----SONG CRWND -___ ~~ _ __. ___-____ _______ - 5265 ___ _-_ _ _ __- -___-- __- -_-5285 - --- STA.-f~t00-- - _ _ ___ _ _ _ _ - - wONMENI' __--_-__ __ _ _ _ _ __ __ _ _ __ _ _ __ _ _ ____ __- _ _ -__-_-__-_ ____ _ __ _ 5260____ _ ____.__ __ __ ___ ___- ~__ 5260 - __ _ TOP_OF BERM~3255.52 _ _ ___-___-__-_-___-- ____ __- _ OSm~CRADE __-_- __ -_ _-_ _ 5265 -- - _ -_-_- _____ _______--5265 --- STA-21tA0- -- - _ ___ wCNNENT - _-_ _ _ __ _____ -____ _ _~ QF WALL-526028 _ ________ _ EXISTING GROU_ _ _ - _-____ - 5260__ _-._____ _-__.~ _________5260 _ --~_____ --~~FOOTER~5~82'- -_ - ~~_ __ _-__ SiTNGi TtOUND- 5235"-- ~ 5245 5255 _ _ . 5255 5255 _ 5855 -_--_ -_- _-_________- ~..-_-__-_--- _ _ --_-_-_ ___ OTTOM OF FOOTER~5233.86 _ -_ 5240_-_- ___ _ __ __ _ _ _ _ _ -__ _ _ 5240 5250 _ _ _ _ _ __ __ __ _ _ 5250 5250 ____ _ _ __ _ _ -_ __ _ _ _ _ . _ _ _ ___ __ __ 5250 ~ I 5235 1DL D 10R -53 2 70C D fOR 52 52~ lOL b 1 R 2 i I S'LSS 9YSS - -STA.-74100------ - wGNMlN I -- -- - '_ TOP OF BERM-3230.27 _ -__ _ __ PROPO6hV GRADE _ - _- 5250 ~ ~ -FWS11Nq GRftI TAI- 52TJ i I 5265 ~ 5465 ---------STA.-18t00------ - wW7YH1I ' _-_ __ _ _ _ _ _-. ___ _ _ - TJ26~~--- - ~7f1P DF WAI I ~R7S] y ~$26(S _ , ~ I DF RER11~5255.06 - . T 52~ ',i 5245 _ _ _ 52~0___-_.. __._-_ ___._____- _____-__-_ _5240 $235 10C D 7OR 5235 PROPOSEOIGRADE EXISiINGi GROUND _ X255 ~ - TOP FOQgFt-S35~g4 5255 -.. _ _.-. / J -- 5250__-___-___,-____-- Q7TdI OF F001ER~575103 5250 5245 1OL b 70R 5245 -26Tf--`---- FA.-75100 5250 -"------'-- AIGNMENT----- 328 I FA. Y9fA0 26 --- ALIGNMENT----- -- - - - 5255 T~-- --- -5255- --TOP OF BERM~5251.85 - 52615----- - - __ P (SF~/GQ~B2b&~~ -_-- - 5260 - OPO3ED GRADE _ - S71NC GROUND __ DBSIINC ~GROU ND~ _ - 70P OF F007EN~3254.b1 -- -- - 5250 i 5450 V 5255 ___ _ _ ~~ -- -_-- -___ -____ T sz4s s2as --- - BOTId1 OF FOOTER~3252.35 szsD szso __ __- ___ ---------- - - - - -- --- --- - _ _ _ _-_b ___ 10R _v,__ 5240 5240 lOL _ _ ~-~0 .. __-- 70R 5245 5245 -_-___ IOC __ - ___ ~ 5260 ----- ~-------538 _ ___- STA-16100--_ __ 52fi5 5 - -STA~Ot - ------Al7CN MEAT ~u - _ _-_-___ 525$ - _--- TOP-OP BERM=525~eD - -OPO~D GRADE -52 -- --- 526D __ PRQPOSED I~RADE TOP OF WALL~5259 4B - _____- -L PQ-~F y¢(M_3357 48 520 _ --____ __ _ _ EXISSINCIGRWN _ _ __---_- __ ~ __ -STING GROUND ~___-_ ~~ TOP OF FOOlER~525Ae2-_ 5250 ~ '~ 5250 5255 5255 .~ _- '. _ TIOM OF FOOTER~525318 _- - __-- 5245 5245 _ _ -' - ~ -5251) 5250 _ --_ -_-__.__ 5_240 - - _- IOC -__ ___ _ _ O_._7©R_ __ -_ __5240 ___ 5245____-_ f9L ___ _ - =o- _- - - __~ _ _ 5245 -^ ~.~ Pua Englnaen sDEreytl~a BOULDER COMMUNITY HOSPITAL BOU LDER COMMUNITY HOSPITAL omwm em PRJ mrzw. oESO'nwa R..rz CRAWIP nm BEAR CANYON CREEK IAm ¢wwi (.w~) uz_~ ovw er 1 CHIC TAW mae pie) ]60.WaT t1W BALSAM STREET 90ULDFR COIORADD EAST CAMPUS SITE PRJ LE VLE wo mnx faro) ssibus CONTACT MIKE MLNAN (D0.1) uo-xu] A RAPAHOS AVENUE-AT 46TH STREET uu•E«tc er CROSS-SECTIONS BOULDEfi, COLORADO ~ ~p RECT 00P."~RTH(iR"...lt^ !~S `tom 31839 f~=° S•t. ..' ~A• NOT VALID WIMOVT ORIGINAL SIGNATURE AND DATE d,. 19 DEC 2007 ~"EW-1149 LV sl¢' " 5~`5~ ~ 5D 638 4 . ~°z5'