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HomeMy WebLinkAboutLand Use Case.1150 River Dr.A081-02 ("'<;, CASE NUMBER PARCEL In # CASE NAME PROJECT ADDRESS PLANNER CASE TYPE OWNER/APPLICANT REPRESENTATIVE DATE OF FINAL ACTION CITY COUNCIL ACTION PZ ACTION ADMIN ACTION BOA ACTION DATE CLOSED BY ~ ; A081-02 2735-013-07004 Joy Stream bank Stabilization Project 1150 River Drive Fred Jarman Stream Margin Exemption William and Sarah Joy Beach Environmental LLC 4/10/02 Approved w/ Condition 1 0/3/02 J. Lindt f',. ('"'\ t- 'j 11 (') n NOTICE OF APPROVAL To: Julie Ann Woods, Community Development Director Joyce Ohlson, Deputy Director RE: Fred Jarman, Planne~;S Joy Streambank Stabilization Project FROM: DATE: " 'fJ> 1160 River driv 1150 River Driv Road Name Topography City Line Structures Water bodies Parcels c~:, ".'\" :,;:+\ '-.; '~ I~~.~, ^" ;;",;;, ..~ ._...~ > .~r.'.:.. '~,', -.......,;'''.. ..... ,~,,""'<,r / ~1~, ' N W*E ',' .:1::\1.', ........ :\: . ,v':' :"'"'' . """,'-:,,:, .~, ,",,:~.., . s Recommended Action: Approval with Conditions Project Description: hydrologic forces are eroding the present stream bank along 1150 and 1160 River Drive, shown above. The Applicant is requesting approval to stabilize the bank with an environmentally sensitive design incorporating bio-engineering techniques such as native plant materials, geotextile mesh, stone- toe protection, and coir logs for a more sensitive approach to stabilizing the bank from further erosion. Applicant: William and Sara Joy Representative: Beach Environmental, LLC Project Location: 1150 River Drive, Aspen Zone District: R-30 (Low-Density Residential) f"""'\ t""1 Staff Comments Due to hydrologic forces that are eroding the present stream bank along 1150 and 1160 River Drive, the applicants, William and Sara Joy, are requesting approval to stabilize the bank with an environmentally sensitive design incorporating bio-engineering techniques such as native plant materials, geotextile mesh, stone-toe protection, and coir logs for a more sensitive approach to stabilizing the bank from further erosion. The subject stretch of bank proposed for re-stabilization is approximately 300 feet in length and has been analyzed into five "sites." A brief summary of the sites and proposed actions are listed below: Site 1: The applicants placed an 85-foot long stone wall with a slope of 2: 1 along the southeastern portion of the bank several years ago as a "hard fix" to erosion problems. This wall has begun to show signs of undercutting and erosion. The applicants propose to remove the wall and replace with fill, and install vegetative erosion control as specified in the plan. The applicants proposed to add three boulders in the river in this section to divert flow force away from this bank area while providing for fish habitat. Staff strongly disagreed with the boulder additions and requested the applicant remove them from the proposed plan. With this change, Staff finds this to be an appropriate method for stabilization. Site 2: This section is a 35-foot section of steeply eroded bank, which is also failing. The applicants propose to construct a 2: 1 slope using vegetative controls. Staff finds this to be an appropriate method for stabilization. Site 3: This section consists of 58 feet of somewhat eroded bank. The remediation proposed for this area is limited to native vegetation planting. Staff finds this to be an appropriate method for stabilization. Site 4: This section consists of 90 linear feet with some boulders placed for limited erosion control. The applicants propose to remove the large boulders and to rebuild the 2:1 slope with native vegetative controls. Staff finds this to be an appropriate method for stabilization. Site 5: This last area consists of a linear stretch of 32 feet, which is currently stabilized with felled logs that are anchored into the slope with ropes to overhanging trees. The applicants proposed to reinforce the felled logs with coir logs (a coir log is a cylindrical structure made of coconut fiber bound together with woven twine to protect slopes from erosion while trapping sediment; they also encourage plant growth within the fiber roll) to reinforce the erosional gaps. Staff finds this to be an appropriate method for stabilization. r, r"'\ >" (Please see the detailed written description and site sections provided in the application that outline the proposed actions for each section) City of Aspen Parks, Engineering, and Community Development Departments and representative from Beach Environmental, LLC, conducted a site visit on Thursday, May 3'd, 2001, in order to discuss the proposed project. After discussing the project with Community Development Staff, it is our opinion, that this project can be handled as a Steam Margin "Exemption" which is an administrative action authorized by the Community Development Director pursuant to Section 26.435.040(B)(1) of the Aspen Land Use Code which states: Construction of pedestrian or automobile bridges, public trails, or structures for irrigation, drainage, flood control or water diversion, provided plans and specifications are submitted to the City Engineer demonstrating that the structure is engineered to prevent blockage of drainage channels during peak flows and the Community Development Director determines the proposed structure complies, to the extent practical, with the Stream Margin Review Standards. However, given this exemption, the project shall comply, to the extent practical, with the Stream Margin Review Standards including a set of conditions attached with this letter specifically related to this approval. The City of Aspen Parks Department forwarded the following comments regarding this project. Specifically, that 1) a detailed plant list must be submitted prior to the project commencing. The Parks Department shall have final approval for plant species; 2) the applicant should consider mulching the access way into the project area. No trees are permitted to be removed and no excavation should occur within the driplines of the trees; and 3) the City Forester (Stephen) shall be contacted for a site inspection during the project as well as a post project inspection. The Parks Department endorses this project and commends the applicants and project engineer for taking this bio-engineering approach to stabilize the bank, further indicating this is a good project and should be used as a model for future bank stabilization repairs and projects. The City Engineering Department indicated concern as to the potential for down stream scouring or upstream flooding during peak flows as a result of changing the flow dynamics at the Joy property due to this project. Specifically, by altering the way the river flows in direction and capacity, there may be more serious consequences further down stream or upstream as a result. The Engineering Department met with the applicant's representative to determine what impacts might occur and what methods could be used to mitigate them. The Applicant has provided a flood profile analysis to the Engineering department that determined that the placement of 90 cubic yards of material along the stream bank will have an almost imperceptible effect on the river's water surface elevation. This report satisfied all concerns of the Engineering Department. t""'\ ,-" " I In Summary, the Community Development Department approves this project as a Stream Margin Exemption with the following conditions: Conditions of Approval: 1. That applicant shall ensure the proposed development does not pollute or interfere with the natural changes of the river, stream or other tributary, including erosion and/or sedimentation during construction. 2. The Applicant shall provide written notice to the Colorado Water Conservation Board prior to any alteration or relocation of a watercourse, and a copy of said notice is submitted to the Federal Emergency Management Agency and the Community Development Department. 3. The Applicant shall provide the Community Development Department and Engineering Department with copies of all necessary federal and state permits relating to work within the one-hundred-year floodplain. 4. The Applicant shall provide the Parks Department with an approved detailed plant list prior to the project commencing. 5. The Applicant shall contact the City Forester (Stephen Ellesperman) for a site inspection during the project as well as a post project inspection. 6. The Applicant shall provide a letter from Mike Claffy at the Army Corps of Engineers approving the work to the Engineering Department. Community Development Director Decision The Community Development Director finds the Stream Margin Review Exemption is consistent with the review criteria, and hereby approves the exemption contingent upon coftpliance with the conditions stated herein and required for this approval. GV\~11jlftW ~1lrt1) fstw ~~, DZ Julie Ann Woods, Community Development Director Date "SUPPORTING DECISION DOCUMENTATION REQUIRED AS PART OF THIS DECISION OF APPROVAL CONSISTING OF THE ArrACHMENTS LISTED BELOW MAY BE FOUND IN THE CORRESPONDING LAND USE FILE AT THE CITY HALL. ATTACHMENTS: Exhibit A -- Review Criteria & Staff Findings Exhibit B -- Application Letter r"\ ("'\ , Exhibit A 1) It can be demonstrated that any proposed development, which is in the Special Flood Hazard Area, will not increase the base flood elevation on the parcel proposed for development. This shall be demonstrated by an engineering study prepared by a professional engineer registered to practice in the State of Colorado which shows that the base flood elevation will not be raised, including, but not limited to, proposing mitigation techniques on or off-site which compensate for any base flood elevation increase caused by the development; and Staff Finding At the time the proposed project was submitted, the Applicant did not present any information indicating that this propose project will not increase the base flood elevation on the parcel proposed for development. However, Staff included a condition of this approval that required the applicant to submit an engineering study to the Engineering Department that demonstrate~ that any proposed development which is in the Special Flood Hazard Area will not increase the base flood elevation on the parcel proposed for development. Specifically, this shall be demonstrated by an engineering study prepared by a professional engineer registered to practice in the State of Colorado which shows that the base flood elevation will not be raised, including, but not limited to, proposing mitigation techniques on or off-site which compensate for any base flood elevation increase caused by the development. This report has been completed and submitted to the Engineering Department; it determines that the placement of 90 cubic yards of material along the stream bank will have an almost imperceptible effect on the river's water surface elevation. This report satisfied all concerns of the Engineering and Community development Department. 2) The recommendations of the Aspen Area Community Plan: Parks/Recreation/Open Space/Trails Plan and the Roaring Fork River Greenway Plan are implemented in the proposed plan for development, to the greatest extent practicable. Areas of historic public use or access shall be dedicated via a recorded easement for public use. A fisherman's easement granting public fishing access within the high water boundaries of the river course shall be granted via a recorded "Fisherman's Easement;" and, Staff Finding Staff finds that the proposed bank stabilization project is consistent with the Aspen Area Community Plan: Parks/Recreation/Open Space/Trails Plan to the extent practicable by protecting the stream bank from further erosion so that soil is not continually eroded into the stream and thereby increasing sedimentation of soil particulates or suspended solids as well as altering the water course downstream. A A , This is consistent with Goal E of the AACP regarding protecting and enhancing the natural environment. 3) There is no vegetation removed or damaged or slope grade changes (cut or fill) made outside of a specifically defined building envelope. A building envelope shall be designated by this review and said envelope shall be barricaded prior to issuance of any demolition, excavation or building permits. The barricades shall remain in place until the issuance of Certificates of Occupancy; and Staff Finding Staff referred this application to the City Parks Department who forwarded the following comments regarding this project. Specifically, that 1) a detailed plant list must be submitted prior to the project commencing. The Parks Department shall have final approval for plant species; 2) the applicant should consider mulching the access way into the project area. No trees are permitted to be removed and no excavation should occur within the driplines of the trees; and 3) the City Forester (Stephen) shall be contacted for a site inspection during the project as well as a post project inspection. The Parks Department endorses this project and commends the applicants and project engineer for taking this bio-engineering approach to stabilize the bank, further indicating this is a good project and should be used as a model for future bank stabilization repairs and projects. Further, Staff has included as a condition of approval that the applicant shall ensure the proposed development does not pollute or interfere with the natural changes of the river, stream or other tributary, including erosion and/or sedimentation during construction. 4) The proposed development does not pollute or interfere with the natural changes of the river, stream or other tributary, including erosion and/or sedimentation during construction. Increased on-site drainage shall be accommodated within the parcel to prevent entry into the river or onto its banks. Pools or hot tubs cannot be drained outside of the designated building envelope; and Staff Finding Staff has included as a condition of approval that the applicant shall ensure the proposed development does not pollute or interfere with the natural changes of the river, stream or other tributary, including erosion and! or sedimentation during construction. Further, the Applicant shall contact the City Forester (Stephen) for a site inspection during the project as well as a post project inspection. 5) Written notice is given to the Colorado Water Conservation Board prior to any alteration or relocation of a water course, and a copy of said notice is submitted to the Federal Emergency Management Agency; and ,-". ~ j Staff Finding As a condition of approval, the Applicant shall be required to provide written notice to the Colorado Water Conservation Board prior to any alteration or relocation of a watercourse, and a copy of said notice is submitted to the Federal Emergency Management Agency and the Community Development Department. However, the Applicant does not intend to alter the course of the river as a result of this project. The focus of the project work will be to reinforce the existing bank through a sensitive bio-engineering approach treatment of the bank restabilization with appropriate materials and plants. Staff met with the Applicant and Engineering Department regarding any further studies for watercourse changes. Ultimately, the Engineering Department required, prior to approval, that the Applicant shall conduct a survey of the cross sectioning of the existing and proposed river channel, using 3 sections and said study shall be stamped by a licensed surveyor in the State of Colorado. Further, the Engineering Department required a letter from a professional engineer registered in the State of Colorado stating that no upstream or downstream degradation will result from the proposed project. Finally, the Engineering Department required that the Applicant provide a letter from Mike Claffy at the Army Corps of Engineers approving the work. 6) A guarantee is provided in the event a water course is alter.ed or relocated, that applies to the developer and his heirs, successors and assigns that ensures that the flood carrying capacity on the parcel is not diminished; and Staff Finding The Applicant contends that the watercourse will not be altered as a result of this project. Please refer to the response provided in the review standard number 6 above. More specifically, the Engineering Department required the Applicant to conduct a HEC-RAS computer model analysis to determine upstream and down stream effects of the project. The analysis indicated that the placement of 90 cubic yards of material along the stream bank "will have an almost imperceptible effect on the river's water surface elevation." In addition, "the placement of this material through this reach of the river will have an incoIlsequential impact and is likely to be similar to the impact of created by such natural phenomena as waves and floating debris. This report satisfied all concerns of the Engineering Department. 7) Copies are provided of all necessary federal and state permits relating to work within the one-hundred-year floodplain; and Staff Finding The Applicant provided a letter from the Army Corps of Engineers to the property owners (Joy) that indicated that the Corps of Engineers had issued a nationwide general permit number 13 which authorizes "the discharge of dredged or fill materials in waters of the United States for bank stabilization." The Corps f"1 f) of Engineers also determined that this project "will not affect threatened or endangered species protected by the Endangered Species Act. Your project can be constructed under this authority provided the work meets the conditions listed on the enclosed information sheets." The Applicant has further addressed these conditions in their application. 8) There is no development other than approved native vegetation planting taking place below the top of slope or within fifteen (15) feet of the top of slope or the high waterline, whichever is most restrictive. This is an effort to protect the existing riparian vegetation and bank stability; and Staff Finding This project is a bank stabilization project intended to reinforce the stream bank to assist in flood control and correct any further water diversion as a result of the bank erosion. The project will occur at the water's edge, which is below the top of bank. As such the effort of the project to protect the bank stability. Staff has included a condition of approval requiring that the applicant provide the Parks Department with an approved detailed plant list prior to the project commencing. 9) All development outside the fifteen (15) foot setback from the top of slope does not exceed a height delineated by a line drawn at a forty-five (45) degree angle from ground level at the top of slope. Height shall be measured and determined by the Community Development Director using the definition for height set forth at Section 26.04.100 and method of calculating height set forth at Section 26.575.020 (See Figure "A" below for illustrative purposes); and Staff Finding This standard does not apply as the development takes place on the water's edge. 10) A landscape plan is submitted with all development applications. Such plan shall limit new plantings (including trees, shrubs, flowers, and grasses) outside of the designated building envelope on the river side to native riparian vegetation; and Staff Finding Staff has required the applicant to applicant provide the Parks Department with an approved detailed plant list prior to the project commencing. 11) All exterior lighting is low and downcast with no light(s) directed toward the river or located down the slope and shall be in compliance with section 26.575.150; and Staff Finding ~ (') -2- April 15, 2002 Staff has brought this to the attention of the Applicant and has included the requirement as a condition of this approval. 12) Site sections drawn by a registered architect, landscape architect, or engineer are submitted showing all existing and proposed site elements, the top of slope, and pertinent elevations above sea level; and Staff Finding The applicant has provided extensive detailed site plans including site sections depicting the areas proposed for stabilization with extensive details regarding the mean water elevations and proposed techniques. Ultimately, the Engineering Department required, prior to approval, that the Applicant shall conduct a survey of the cross sectioning of the existing and proposed river channel, using 3 sections and said study shall be stamped by a licensed surveyor in the State of Colorado. Further, the Engineering Department required a letter from a professional engineer registered in the State of Colorado stating that no upstream or downstream degradation will result from the proposed project. Finally, the owners of the property had the property surveyed by High Country Engineering on September 17, 2001. Cross-sections developed through the survey were used in a HEC-RAS computer model to determine the changes in flood elevation that would result from the proposed stream bank stabilization project. The result of the analysis determined that the placement of 90 cubic yards of material along the stream bank would have an almost imperceptible effect on the river's water surface elevation. This report satisfied all concerns of the Engineering Department. 13) There has been accurate identification of wetlands and riparian zones. Staff Finding The Applicant has indicated in response to the Army Corps of Engineers that the proposed bank stabilization does not impair flow into or out of any wetland area. ~ ("'l, ,"'" Joy Stream Bank Stabilization Project Roaring Fork River Report Prepared by: Jorine Lawyer & Tara McGowan Environmental Scientist & Staff Engineer Beach Environmental, LLC March 8, 2001 ,1 -.. .."l G CITY OF ASPEN 080143 i. ~~ri I \ \ t _ \ L_J ZONE X PITKIN fQUNTY CITY OF ASPEN PITKIN COUNTY UNlNCORPORA TED AREAS 080287 ZONE X ZO,!e ~ > ~ CITY OF ASPEN 080143 @ IIZD :'ON IliL Wl NMVlIO .DE-.' ::nv tSLt-Sl:6(OL6)XV.:l SLK-!il:6 (0 L6)'H'd I.~ Ug~g o::l 'N3dSV 'rOt 3Llns 1:33H.1.S NIVI'l 153M S \.L :m 1V1N3I'lNO~II\N3 H:>V38 :SNOISV\3H IO/eh :3I.VO NVlcl ;llJ6 ml'mlcl NOl1vznK!V16 )INVQrfomI16 AOOcImIcI ).Dr Ct: W o -l ::> o CD C) z i= (I) x w VI oc w 9 ::> o ID o W VI o 0.. o oc 0.. 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Project Objective To stabilize banks that are presently threatened by the erosive forces of the river on the Joy property. The existing rock wall no longer provides adequate protection and is beginning to fail due to undercutting and lack of restraint The pore spaces between the rocks allow sediment to escape and will eventually lead to additional slumping and failure of the slope. A staff engineer and scientist completed an initial survey in October 2000. Design decisions were made using a variety of stream stabilization techniques emphasizing bioengineering. Bioengineering uses vegetation and organic structural materials to provide stability and control erosion while enhancing habitat and stream aesthetics. . The use of "hard" barriers such as rock is held to a practical minimum, with the design purpose being to establish a vigorous, sustainable native or naturalized plant community as the primary erosion control mechanism. There are a variety of bioengineering methods that can be used in different combinations to fit a diverse set of conditions. Using bioengineering in conjunction with principles of fluvial geomorphology will provide an environmentally sensitive protection design. Project Location William and Sara Joy 1150 Ri ver Dri ve Aspen, Colorado 81611 Roaring Fork River in Pitkin County, Colorado, below the confluence of the Roaring Fork River and Castle Creek in the SW 1/4 of Section 1, Township 10 S, Range 85 W. The drainage area is approximately 228 square miles. See vicinity map for details (Figure 1). Roaring Fork River The United States Geological Survey (USGS) maintains historical data from the Roaring Fork River based on various gauging stations along the River. The closest USGS gauging station to the Joy property is located near the intersection with Cemetery Lane. This station provided data from the years 1913-1918 but was taken out of service. Due to the short time period, the flow velocities may not be accurate due to the influence of decadal climatic regimes and post 1918 upstream diversions. However, it should give a general idea of the rivers behavior. The river characteristically has low discharge 9 months out of the year during fall and winter, and higher discharges during a typical snowmelt season, April -July (See Figure 2). Construction for this project is recommended in late fall to maximize the growing season for vegetative species and due to the dormancy requirements for cuttings. Beach Environmental. LLC Joy Stream Bank Stabilization r'"'\ r\. hearing Fork River ~lo~Veloch{ 1913-191$ (Fig. 2) c 'g 3500 1i 3000 ~ 2500 .~ 2000 x ~ 1500 '" 1000 Ol 1;! 500 ~ 0 <( Jan Feb Mar April May June Jl.il Aug Sep Oct Nov Dec Month --- Average CFS , , I , I - I I , , Role of Vegetation in Slope Stability Vegetation interacts with the bank's materials and creates long-term stabilization through the use of a variety of processes. For streambank restoration, the role of vegetation acts threefold. First, root systems will work to bind soil particles together in the streambank, while the exposed branches and leaves will act to trap sediment in those portions that are exposed to water. Second, vegetation structures will increase roughness, slowing down the velocity of water and reducing the stress at the soil/water interface. Lastly, vegetation with non-rigid stems such as willows will bend during high flows and effectively armor the bank. Proposed Techniques After review of the Roaring Fork River system on the Joy property, three major restorative techniques were chosen to stabiiize the banks since there are several varying conditions that exist across the site. A brief description of each technique and their respective sites will follow. Boulder Clusters: Strategically placed groups of boulders in the base flow channel will provide cover, create scour holes, or areas of reduced velocity. This method benefits streams that exceed 2 cubic feet per second (CFS). Group placement is most desirable and it is most effective in wide shallow streams with gravel beds. The added erosive forces might cause channel and bank failures, however they will be placed in areas upstream of the erosion site to reduce this possibility. This technique was chosen due to the availability of materials on site. See site plan for details. . Beach 'Environmental, LLC Joy Stream Bank Stabilization -. ,-.. r'"'\ 1 Brushlavering with Stone Toe Protection: A ridge of quarried rock or stream cob.ble placed at the toe of the streambank as an armor to deflect flow from the bank, stabilize the slope and promote sediment deposition. This technique will be used in areas that are below the high water line where vegetation cannot be used. This toe protection will be used in combination with soil bioengineering systems. See Figure 4 for details loint Plantings/ Live Staking: This technique is useful in areas that are presently riprapped and will provide better aesthetics and drainage of the bank. Live stakes are installed between openings of the rock into the stream bank. Joint planting must be implemented during the dormancy period of chosen plant species, late fall to early spring. See Figure 5 for details. Coir Logs: This technique uses cylindrical structures made of coconut fiber or other fibrous material and bound together with woven twine to protect slopes from erosion while trapping sediment. Coir logs encourage plant growth within the fiber roll. They are flexible for molding to the side of the bank and have an effective life of 6 - 10 years. Subsequent to this time, the trapped sediment and vegetation will provide for a stable channel. They are buoyant and require secure anchoring. See Figure 6 for details. Army Corps of Engineers Permitting To protect the banks along the Joy property, fill material will be needed to stabilize some of the undercut banks, thus subjecting this project to the federal permitting process. The Army Corps of Engineers has the authority to issue permits for discharging dredged and fill material into wetlands under the Clean Water A.ct u~ing a Section 404 permit. However, due to the lengthy permitting process, a Nationwide Permit may substitute for a Section 404 under certain conditions and limitations set by the Corps. Nationwide permits are designed to expedite processing of projects that, individually and cumulatively, have little or no adverse effect on the environment. This project qualifies for a Nationwid.e Permit #13 BaIlk St:ibiHz:it@:J. The f()llowing are terms and conditions set by the Corps under this permitting process. Under each condition there is a written response verifying that our project falls under these conditions. Beach Environmental. LLC Joy Stream Bank Stabilization "-.,, ~ , Bank stabilization activities necessary for erosion prevention are authorized provided that (Modified from Federal Register Vol. 61, No. 241 December 13, 1996): A. No material is placed in excess of the minimum neededforerosion protection; The minimum amount of material will be used to stabilize these banks. See engineering plans for details. B. The bank stabilization activity is less than 500 feet in length; The 300 feet of streambank to be protected through this stabilization project is below the maximum length. c. The activity will not exceed an average of one cubic yard per running foot placed along the bank below the plane of the ordinary high water mark or the high tide line; The material placed below the high water mark will not exceed an average of one cubic yard per running foot. Total fill to be used is approximately 140 cubic yards. d. No material is placed in any special aquatic site, including wetlands; Although riffle and pool complexes are present, material will not be placed in any of these sites, or if necessary, impacted pool and riffle sequences will be replaced on-site. Ma.terial will only be placed along the bank where it is eroding. e. No material is of the type or is placed in any location or in any manner so as to impair surface water flow into or out of any wetland area; No impairment of flow into or out of any wetland area is proposed. f No material is placed in a manner that will be eroded by normal or expected high flows (properly anchored trees and treetops may be used in low energy areas) Bioengineering stabilization techniques used in this project site are intended to negate this issue. g. The activity is part of a single and complete project. At the time of survey, only 300 feet of bank were in need of stabilization. Bank stabilization activities in excess of 500 feet in length or greater than an average of one cubic yard per running foot may be authorized if the permittee notifies the district engineer in accordance with the "Notification" general condition and the district engineer determines the activity complies with the other terms and conditions of the nationwide permit and the adverse environmental impacts are minimal both individually and cumulatively. (Sections 10 and 404) Beach Environmental, LLC Joy Streambank Stabilization 5 .... ?"""'\ n General Conditions requirements for ~WP - (Modified from Federal Register Vol. 65, No. 47 March 9, 2000) The following are terms and conditions set by the Corps as "general conditions". Under each condition there is a written response verifying that our project falls under these conditions 1) That the activity may not cause more than a minimal adverse effect on navigation. There are no proposed effects on navigation activities on the Roaring Fork River 2) That the structure offill will be properly maintained The use of vegetation for stabilization should result in a maintenance frr:e fill structure. 3) That appropriate erosion and siltation controls will be used and maintained during construction. Erosion and siltation will be kept to a minimum during stabilization installation. 4) That any activity shall not substantially disrupt the movement of indigenous aquatic species unless the primary purpose of the fill is to impound water. Proposed activities are not anticipated to disrupt the movement of indigenous aquatic species. 5) That heavy equipment must be placed on mats or other measures taken to minimize soil disturbance, This requirement will be adhered to. 6) That the actively complies with regional and case specific conditions. This activity complies with all regional and case specific conditions. 7) That the activity will not occur in a component of the National Wild and Scenic River System, nor in a river officially designated by Congress as a "Study River" for possible inclusion in the system while the river is in an official study status. The Roaring Fork River in Colorado is not part of the National Wild & Scenic River System. . 8) That the activity will not impair reserved tribal rights, including, but not limited to, reserved water rights and treaty fishing and hunting rights. . This activity wiIl not impair any orotected federal reserved ri2:hts. Beach Environmental, LLC Joy Streambank Stabilization 6 ,~ "..,. n 9) That in certain states and individual state water quality certification must be obtained or waived. The Colorado Department of Water Resources was contacted and there are no requirements for this activity. 10) That an individual state coastal zone management consistency concurrence must be obtained and waived in certain states. Not applicable in Colorado 11) That the activity will not jeopardize a threatened or endangered species as identified under the Endangered Species Act, or destroy or adversely modify the critical habitat of such species and, if the presence or proximity of endangered species is known, non-Federal permittee must notify the Corps and wait for its approval. Bill Clark, biologist for the Colorado Di vision of Wildlife has confirmed that there are no threatened or endangered species in this particular area, and in fact a bioengineering project will enhance wildlife habitat, water quality, and fish habitat. 12) If the activity may adversely affect historic properties which the National Park Services has listed on, or are or may be eligible for listing on, the National Register of Historic Places, that the permittee shall notify the Corps and wait for its approval There are no historic properties on si te. 13) Where notification is required, that the permittee has compiled with the specific notification provisions, including a delineation where required. A proposed mitigation plan may also be submitted with the "Pre-Construction Notification" or PCN As proposed, notification for this project is not required. 14) Compliance Certification - The permittee who receives a Nationwide Permit Verification must submit a signed certification regarding the completed work and any required mitigation. N/A. The project will not receive a Nationwide Permit Verification. 15) Use of Multiple Nationwide Permits - The use of more than one NWP fora single and complete project is prohibited. Only NWP 13 will be used for this project. 16) Water Supply Intakes - No activity, including structures and work in navigable waters of the U.S. may occur in the proximity of a public water supply intake except where the activity is I for renair of the nublic water sUTmlv intake structures or adiacent bank stabilization. Beach Environmental, LLC Joy Streambank Stabilization 7 ,,-, n The activity will not be in the proximity of a public water supply intake. 17) Shellfish Beds - No activity may occur in areas of concentrated shellfish populations. The activity does not occur in areas where shellfish are present. 18) Suitable Material. Fill materials may not consist of unsuitable material such as trash, debris, car bodies, asphalt, etc.. Materials used for construction must be free from toxic !pollutants. All fill will be of suitable material and will be approved by Beach Environmental. 19) Mitigation - The project must be designed and constructed to avoid and minimize adverse effect to waters of the US to the maximum extent practicable. Mitigation will be required when necessary to ensure that the adverse effects to the aquatic environment are minimal. No mitigation is necessary for this project. 20) Spawning Areas - Activities including structures and work in navigable waters of the United States or discharges of dredged or fill material, in spawning areas during spawning seasons must be avoided to the maximum extent practicable, Spawning of the native cutthroat trout and non-native rainbow trout takes place in the Spring. Brook and Brown trout are fall spawners. Stabilization work will be scheduled for late fall, winter, or early summer to avoid spawning season. 21) Management of Water Flows. To the maximum extent practicable, the activity must be designed to maintain preconstruction downstream flow conditions. Furthermore, the activity must not permanently restrict or impede the passage or normal orhighflows. The project will not affect downstream flow conditions or restrict normill or high water flows. 22) Adverse Effectsfrom Impoundments. If the activity, including structures and work in navigable waters of the US or discharge creates an impoundment of water, adverse effects to the aquatic system caused by accelerated passage of water shall be minimized to the maximum extent practicable This project will not cause impoundments of water. 23) Waterfowl Breeding Areas - Activities into breeding areas shall be minimized to the maximum practicable extent. This project does not affect waterfowl breeding areas. 24) Removal of temporary fills - Any temporary fills must be removed in their entirety and the affected areas returned to their preexistinJ! elevation. Beach Environmental, LLC Joy Streambank Stabilization 8 ~ ,~ All temporary fills will be removed at the conclusion of this project. 25) Designated Critical Resource Waters - Projects are not authorized in critical resource waters without DubUc avvroval. The Roaring Fork River is not a critical resource water. 26) Fills within 100-year Floodplains - Above grade fills within the 100 year floodplain are not authorized by NWP 29,39,40,42,43, and 44. For NWP 12 and 14, the permittee must notify the District Engineer in accordance with General Condition 13 and document that any permanent above grade fills in waters of the US within the 100 year floodplain comply wilh FEMA construction requirements. N/A. Application is for a Nationwide Permit #13 Site Plan Details: The entire length of stream bank that requires restoration is approximately 300 feet and is broken up into four different sites (see site plan for details). Each site requires different methods of stabilization. Site 1: Stone Wall The existing stonewall extends for approximately 85 linear feet and is not providing adequate erosion protection to the bank. Small gaps between the stones have allowed water to infiltrate, and remove sediment from behind the stonewall and slumping has commenced. The corrective course of action involves removal of the stonewall and rebuilding the slope (2: 1) using vegetative erosion controls. The base of the slope will use stone-toe protection up to the high water mark. Geotextile mesh and burlap will be used underneath the stone-toe protection and to hold the fill of the rebuilt slope while the vegetation takes root. Native vegetation provided by Rocky Mountain Native plants will be used above the high-water line and placed in holes made in the geotextile mesh. 6). Additionally, three boulders are proposed to be placed in the Roaring Fork River for water deflection away from the bank and to create fish habitat downstream. See site plan for details. Erosion control techniques are illustrated in greater detail in figures 3 and 4. Beach Environmental, LLC Joy Streambank Stabilization 9 ':t.: .~,; r- f~ Site 2: Steep Eroded Slope This area extends 35 linear feet and is currently failing. The corrective course of action involves rebuilding the slope (2: 1) using vegetative erosion controls. The base of the slope will use stone- toe protection up to the high water mark. Geotextile mesh and burlap will be used underneath the stone-toe protection and to hold the fill of the rebuilt slope while vegetation takes root. Native vegetation provided by Rocky Mountain Native plants will be used above the high-water line and placed in holes made in the geotextile mesh. See site plan for details. Erosion control techniques are illustrated in greater detail in figure 4. Site 3: Slope supported by small boulders This area extends 58 linear feet and has small pockets of erosion. Due to the small amount of erosion in this area, only vegetative erosion controls are needed. The stable slope and presence of some vegetation alleviates the need for geotextile mesh in this area. Native vegetation provided by Rocky Mountain Native plants will be used in places sparse of vegetation. See site plan for details. Erosion control techniques are illustrated in greater detail in figure 5. Site 4: Slope supported by large boulders This area extends 90 linear feet; the current. erosion protection is large boulders placed under the bank. The corrective course of action involves removing the large boulders, and rebuilding the slope (2: 1) using vegetative controls. The base of the slope will use stone-toe protection up to the high water mark. Geotextile mesh and burlap will be used underneath the stone-toe. protection and to hold the fill of the rebuilt slope. Native vegetation provided by Rocky Mountain Native plants will be used above the high-water line and placed in holes made in the geotextile mesh. See site plan for details. Erosion control techniques are illustrated in greater detail in figure 4. Site 5: Slope supported by felled logs This area extends 32 linear feet. Current erosion protection is felled logs that are anchored into Beach Environmental, LLC Joy Streambank Stabilization 10 ~ +- ~....-.. .c._-' ,,,-,, r->; the slope with ropes. The corrective course of action for this area is to install coir logs beneath the felled logs to fill in erosional gaps. The ropes will be removed and boulders will be used to anchor the existing logs. See site plan for details. Erosion control techniques are illustrated in greater detail in figure 6. Beach Environmental, llC Joy Streambank Stabilization 11 .. .,.,.-~.~ '1 BEACH ENVIRONMENTAL LLC 715 WEST MAIN STREET SUITE 304 ASPEN, CO 8161.1 .... P.H.(970)925-3475 FAX(970)925-4754 .... ~ n "" ......'... . ..- "~, JOY 5TREAM BANK 5TABIUZATION FROJEcr VICINIlY MAl" fiGURE I DATE: 11/6/00 REVISIONS; JOB NO.: 0269 .f.::,.. _. ,~ TOP OF BANK .... BOULDER CLUSTER AREA OF EROS/ON ~ SITE 1 (ROCK WALL) A METHOD OF LOCATING BOULDER CLUSTERS Boulder clusters to be located based on field conditions. TOP OF BANK NORMAL STREAM LEVEL ROCK SHOULD BE 2' DIAMETER OR LARGER y ~ /(v $;' ~y, ~ ~~ /~V NOT TO SCALE r HIGH WA TER ~ ::> u o '" Z :J: o -, '" 0> 0> ~ ." ," "-". "'" STREAMBEf1. 'v -'/ / /-/ /'>// 12u:::-;] ." '" <' (300mm) L \'\ /' ,,/) KEY BOULDER INTO STREAMBED CROSS SECTION @ '1 BEACH ENVIRONMENTAL LLC 715 WEST MAIN SlREET . SUITE 304 ASPEN. CO 81611 . P.H,(970)925-3475 FAX(970)925-4754 JOY STREAM BANK STABILIZATION FROJECT DETAIL OF BOULDER CLUSTERS FIGURE 3 ~..;~_. DATE: 11/5/00 REVlSJONS: SCALE: NTS DRAWN BY: JOB NO.: JM 0259 .,~;..:=",~.-.,,- r>, n FRONT OF SLOPE BACK OF TERRACE CEO TEXTILE MESH AND BURLAP Crisscross branches 5-8 branches/ft. min. (20/!inear meter) placed at random with regard to size and age. I I I I GEOTEXT/LE MESH AND BURLAP PLAN VIEW .... . --- MHW ~ . .. ~. . 0 .0 .<1 . . . 0 o . ..d' '.. MLW J.oo -.:..: 0 . 00 ". v . . ,Q--:-.a....o", CI 10'-20' . .~. ~~.<1 ,. : . 4" ~ <1." T.- -; -'-.":;;- . . ~.. .. xl <~ o ..<.; . 0 . a. ;&.>V/'- " . . . . . . .".. .. A.-'--- ,V /, '%:' . .' ~';::S'>" - ~ - - '-c,,'- ~ . ;, ~<(:;(0 :..--//0>>>""/~\ NOTES: - /'/A'- ., f. Tilt branches down into the slope 10'-20' min. 2. Brushlayering may be constructed with non-compacted or compacted backftll without damage to the brush layer. 3. Branches irrespective of length, should protrude 8-f81n. (0.20-0.50 meters) beyond the face of the slope. 4. Holes to be cut in burlap to allow plantings through. . ~ ::> \:i :> z :I: o -, '" '" '" @ '1 BEACH ENVIRONMENTAL LLC 715 \'<EST MAIN STREET SUllE 304 ASPEN, CO 81611 . P.H.(970)925-3475 FAX(970)925-4754 JOY STREAM BANK STABIUZATION PROJECT DETAIL OF BRUSH LAYERING FIGURE 4 DAm 11/6/00 REVlSIONS: DRAYtN BY: JOB NO.: ..A.f 0269 , --..."",,-, ,,-,., n TYpical use of willow stakes to anchor willow wattles, straw rolls, bio mats, or turf reinforcement mats. r/iON~ TYpical area staking 1-3ft. (0.3-1m) apart. TYpical - drive or plant willow stakes through openings in riprap or gabions. r Cut top of stake square. 1 \ 2 to 5 buds scars shall be above the ground. ) NOTES: ,. Harvest and plant stakes during the dormant season. 2. Use healthy, straight and live wood at least 1 year old. 3. Make clean cuts and do not damage stakes or split ends during Installation, use a pilot bar in firm SOils. 4. Soak cuttings for 24 hours (mln.) prior to Installation. 5. Tamp the SOil around thtl stake. I V- Trim branchtls close. l J~ )'// .' 3/4-3In. (20-75mm) diamettlr. Plant 80% of stake length into the groun~ angled cut at butt-end, butt-end down. @ 2000 JOHN McCULlAH '1 BEACH ENVIRONMENTAL LlC 715 WEST MAIN STREET SUITE 304 ASPEN, CO 81611 P.H.(970)925-3475 FAX(970)925-4754 JOY 5TREAM BANK 5TABIUZATION f'ROJECT DETAIL OF JOINT f'LANTING5 FIGURE 5 DATE: 11/6/00 REVISIONS: DRAWN BY: JOB NO.: .,1M 0269 ~. ._.,.....e:....,. I"""] ~ . , PLACE COIR ROLLS PARALLEL TO THE STREAMBANK ALONG A HORIZONTAL CONTOUR , !\ !:'.\,~ ]....:'.\, i,' '., '. ' "- \;~:".:""'>,~ " .. , \\:~"~>>\ \,' '\' . . ':. \...A...-^- ,; II " "I .... " I I , ",.'-1 \ T .,\:,,'; /'( \.',:~". . 12)1 """\ 'J' , ))'::'/6fJOmm) '~, k //" '. j , "~j '.;.;,:".., . . '/ ' . ...:." ',' '; . :. ~'I.>.;~~~~ \<)\:' .'. ~0Q,<f~.::::~,:~'::,,::,::" :::,:~..:;.~~S, " //'-//v' /{/ /~/// /~<j<'~~" v("- ' 0 ~ ~ I.~ \ t" Vj 1 y ~,,,' <> ."- z) i, 1/2" X 1 1/2" (38 X 38 mm) RECOMMENDED c.:> DOUBLE STAKES OPTIONAL REQUIRED FOR OFFSHORE INSTALLA TlON LENGTH OF STAKE DETERMINED BY THE SUBSTRATE PLACE CO/R ROLL SUCH THAT THE ROLL EXTENDS 2" (50 mm) ABOVE MEAN WATER ELEVATION MEAN WA TER ELEVATlON~ 2" . :. ~ ::> u o '" :z: 0: o , <0 0> '" ~ --. r--^' ,r') '; ..\,..'.........' /...:-<- ...." /:. ;./,;...~>'. "'\." >"'- ,"-.:.,,- '" /";., ;/, '..~<;,< .,/ > /' / ;--.,/ / <;, J '''-///. o /.... " NOT TO SCALE @ {~-; '1 BEACH ENVIRONMENTAL LLC 715 'M::ST MAIN STREET SUITE 304 ASPEN. CO 81611 P.H.(970)925-3475 FAX(970)925-4754 JOY 5TREAM BANK 5TABIUZATION PROJECT DETAIL OF COiRo LOG5 FIGURE b DRAWN BY: JOB NO.: ..1M 0269 DATE: 11/6/00 REVISIONS; .~,~,- ..-.:;;,;0...'-.:;.....>- " r-., ~ ? 3 .. " ./ ~ PLACE .COIR ROLLS PARALLEL TO THE STREAMBANK ALONG A HORIZONTAl.; CONTOUR ,,<,., ':\ .-"""""'-.~ ..,. '.\ .::;, .r----.-~ j',>" :....'\,.J"-~ .... n., .,---,"..-... ,.......;.-. 7L~~' -:(8POn;m) J.. . . . ':..~:' ., ., ,,.; J!'. LI 1/2N X 7 1/2N (38 X 38 mm) RECOMMENDED ':=) DOUBI.E STAKES OPTIONAL REQUIRED. FOR OFFSHORE. INST;4LLATlON ~ ..' LENGTH- OF STAKE - DETERMINED 9Y7HE SUBSTRATE ,.'., Pl.J!CE.cafR ROLLSUC1:t...71fAT. THEROI.LEXlEl/.DS.. ... -,--':z;'!,/= ---+.;486E:~~........ ~H-~7 ~c(;,~ . .."".._., t~_u.~~'~ , ..... ~-",.. .......'. '-'." ""~-::~. ....~~ < ' ,....,. Y; ".'''.'' '..i.' ,,;..... <'';.i' ",/, F....'." ./," ,,' 7;...' .., ..../>. /,//).... /':,) , '.....J'//. (:J /, " ,'---, NOT TO SCALE ~ M54N WATFR ELEVATION, '\ 2N ....... ~ ,..., \../ '1 BEACH ENVIRONMENTAL ~iic 1'5 v.EST MAIN STREET SUITE 304 ASPEN. C08tStt " ;. . . . P.H.(970)925-:-3475 FAX(97e)925-475<$ JD'( STREAM BANK 5TABIUZAT10N PROJECf DETAIL OF COIR LOGS FlGUREG DATE: , SCALr::: t1/a/CO Nl$ RE"SlOHS: 'l6 .C. CltlJ . > 1"). f) ~1::"""'f~'H!E~" ~"'l.~~.t"~~."~ tJj IbU Beach OCI -5 20111 CllY :t'i\lG@'J,lEEA r-~ Resource Management, LLC Nick Adeh City Engineer City of Aspen 130 South Galena St Aspen, CO 81611 Re: Joy Streambank Stabilization Project Aspen, CO Dear Nick: At your request we have undertaken and completed a flood profile analysis of the Roaring Fork River at the William and Sara Joy property near the northwest city limits of Aspen, Colorado. The Roaring Fork River along the Joy property was surveyed by High Country Engineering on September 17, 2001 and cross-sections developed through the survey were used in a HEC-RAS computer model to determine the changes in flood elevation that would result from the proposed streambank stabilization of the left bank of the Roaring Fork River adjacent to the Joy property. To paraphrase the conclusions of this study and report, the proposed placement of 90 cubic yards of material along this bank will have an almost imperceptible effect on the stream's water surface elevation. In fact, in order to produce a measurable result it was necessary to calculate the surface water elevation change on a ten-year event. It is the engineer's opinion therefore that the results of this study indicate the addition of 90 cubic yards of fill through this reach of the ri ver will have an inconsequential impact and is likely to be similar to the impact created by such nat1.1ral phenomena as waves and floating debris. Therefore, we believe that the City of Aspen can now move forward with the issuance of a permit to allow the streambank stabilization project to proceed. Should you have any questions regarding the HEC study please feel free to give me a call. Sincerely, Gary~ 715 W,.Main Principal wi attachment Cc: S. Broderick 02691.streambank_stabilization.l00201 Suite 304 Aspen. CO 81611 Tel (970) 925-3475 Fax 925-4754 r'J n MEMORANDUM To: Fred Jarman, Planner From: Richard Goulding, Project Engineer Date: May 25, 2001 Re: Joy Stream Meeting Attendance: Nick Adeh, Fred Jarman, Gary Beach, Richard Goulding On Thursday, May 24, 2001 Gary Beach met with the City Engineer, Nick Adeh to discuss the requirements for stabilizing the Joy stream bank. The following conditions are to be met to ensure approval from the engineering department: . 1) Completion of a survey of the cross sectioning of the existing and proposed river channel, using 3 sections and is to be stamped by a licensed surveyor in the state of Colorado 2) A letter from a professional engineer registered in Colorado stating that no upstream or downstream degradation will result from the proposed development 3) A letter from Mike Claffy at the Army Core of Engineers approving the work Lov("S 5"C/3 1'"'"'\ r) Beach Resource Management, LLC IMPACT OF STREAMBANK STABILIZATION PROJECT ON FLOOD HEIGHT OF ROARING FORK RIVER ,,,tnlllll,, ,".., ^LT"' "1 ,,,~~ 'f;'t l""\ t;; l"i ;'; ~... ~. 01'1..... rr L:I'; ...~. .O<:-G\STEfi>e:.'" "~'... ~\" ..,~0- () ." 7....,....-:. . . o-~ :.:.......'1... .0 <.Po:. :<-- ~ '-kl- ... m::. ;- ov eo' V"eJ' : Z; :Jt(- , "':'",: ".. Jv. T- ~ "'...~.\ 4:'./":0 ~ ..../\ (> US' r,.' "'L""\. .. .....",~~J,'.,,:ONAL "€.~*..\.",,'V.......,... "'... 1:0"".....O<?:-";,~...... #"11 F CO\..: "..... ""auuu,\\\ Property of William and Sara Joy 1150 River Drive Aspen, Colorado SW % T 10 N, R 85 W .28 September 2001 William W. Hansen Registered Professional Engineer Red Feather Lakes, Colorado BRM 3.01 () William W. Hansen, P.E. Water Resource Management Consultant 663 Socorro Trail PO Box 227 Red Feather Lakes, Colorado 80545 (970) 881-3500 28 September '01 Mr. Gary L. Beach Beach Resource Management, LLC 715 West Main, Suite 304 Aspen, Colorado 81611 RE: Flood-Profile Analysis Joy Streambank Stabilization Project Your File No. 0269 Dear Gary: This letter and the attachments thereto constitute our report on an investigation of the hydraulic characteristics of the Roaring Fork River where it flows past the Joy property in Aspen, Colorado. The purpose of the investigation is to evaluate the changes in floodwater elevation that would result from a proposed streambank stabilization project on the left bank of the Roaring Fork along the Joy property. PROCEDURES Basic data and procedures were obtained from 1. the Flood Insurance Study (FIS) for Pitkin County, published by the Federal Emergency Management Agency (FEMA) in June, 1987, 2. a field survey conducted by High Country Engineering on 17 September 2001, 3. computer software developed at the Hydrologic Engineering Center (HEC) of the U.s. Army Corps of Engineers for analysis of river hydraulics; the most recent version is entitled HEC-RAS (River Analysis System), Version 3.0 released January 2001, and includes many modifications and improvements to the earlier version (HEC-2), and 4. our own reconnaissance and examination of the site and your files on 10 September 2001. In addition, we have requested the computer printouts of the input and output files of the FIS to see if the data can be incorporated into our investigation. Presumably it is the events of September 11th that have delayed the processing of our order by the FEMA archives in Virginia. 1""'"\ (') Mr. Gary L. Beach 28 September '01 Page 2 PROJECT LOCATION The study area is approximately one mile northwest of downtown Aspen, as shown on Figure 1. The base map for Figure 1 is the Flood Insurance Rate Map (FIRM) for the City of Aspen, published by FEMA as a companion document to the FIS and bearing the same date of publication. Also shown on Figure 1 are the locations of the cross-sections used in the FIS as well as the cross- sections surveyed by High Country Engineering on September 17'h(Sl, S2 & S3). It can easily be observed that the FIS cross-sections at DKand DL would be particularly useful if tying these two studies together were of any importance. SUMMARY OF RESULTS The ten-year flood for the Roaring Fork developed in the FIS was used as a baseline discharge for this analysis. A f10wrate of 3700 cubic feet per second is reported as the appropriate value for the Roaring Fork immediately upstream from the confluence with Maroon Creek. When projected onto the geometric configuration of the river in the study reach the profiles plotted on Figure 2 are obtained. [Nb: on several of the figures and tables the elevation is reported as the truncated value of elevation above Mean Sea Level, i.e.. an elevation of 7742.65 may be written as 42.65 for convenience.] The profiles are virtually indistinguishable at the vertical scale of Figure 1, which has been exaggerated as much as possible to maximize the difference. Only on Table 1, the standard output format for HEC-RAS, can any difference be detected. The figures in bold represent the elevation of the water surface during the lO-year event. The italicized figures represent the addition of approximately 90 cubic yards of fill material along the left bank required for the stabilization thereof. The maximum increase that is prediCted by this procedure is 0.12 feet at the upstream end of the Joy property. This value is not only negligibly small but may be misleading due to the fact that it constitutes the solution to a highly sophisticated mathematical equation with a small change in the value of only one boundary condition. In reality, the complexities and irregularities of the channel, floodplain and river flow will cause departures from predicted flood stages that will be well in excess of 0.12 feet. t""", f"'\ Mr. Gary L. Beach 28 September '01 Page 3 SUMMARY OF INPUT DATA The geometrical data used in the HEC-RAS simulation were obtained from the field survey conducted by High Country Engineering on September 17th. The cross-sections are shown in their relative locations on Figure 1 and are plotted on Figure 3. The 90 cubic yards of fill material required for the stabilization of the embankment is assumed to be uniformly distributed throughout the 300-foot length of bank on the Joy property. Therefore, the average reduction in cross-sectional area will be approximately 8 square feet. The rectangles in the diagrams of Figure 4 are scaled to approximately 2 feet wide by 4 feet high, or about 8 square feet. The modified configuration of the stream bank has been drawn so as to increase the bank volume by roughly the same area as that of the rectangle. The bank configurations labeled as "Proposed" on Figure 4 resulted in the profile labeled "Proposed" on Figure 1 and the portion of Table 1 headed "With Proposed Embankment Improvements". CONCLUSIONS The linear approximations to the "before and after" geometry of the left bank result in a predicted increase of 0.12 feet in the lO-year water surface elevation. It is our opinion that this purely mathematical result is inconsequential in comparison to the variations in the water surface that are caused by natural phenomena such as waves and floating .debris. I hope that this report provides the information needed by staff of the City of Aspen and of Pitkin County. Please feel free to call if there are any questions or need for further investigation. Sincere y your, W\X/H/lg Attachments (5) MOUNTAIN VIEW DRIVE i f"";, f) ZONE X ..~, /t..' ,-r 0' ,:'l,/ !o.'\: , , " , """~~~O ZONE AE ",___.i. ':~',-::'~;::'-Q."~=-=:'~~:'~~~'{~h}i..t.:: ~-; r..(. ., . > , M. ~"1 '. -......." \. --........,.~, "',,\ \\ . /) v..-/ c" " , , I ! I: i I , , 'I 'J I! !~! /2j ROARING FORK RIVER N ! " ii I~I' IOi 101 I<i Iw' !:l! II , , ZONE X Figure 1: LOCATION OF STUDY REACH AND CROSS-SECTIONS /'.-CI6.bfi~LC~:'-'._"---- : i ~ SCALE: 1 inch = 500 feet ".~..~L.,._, ii'" li---~~si"'---'; I / ,I ...........-, ~~~ i" .'~.-. 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(j) 0 :s: C\/ 0:: :;::- ~ - a. - ~ ('oJ .;:: v J: () I- ~ > <Il N iii I;: '" .., '" '" .., CD c: CJi I:: r-: cD lIS :l "l' "l' "l' 0:: ~ iii .<= ro lO lO () ~ ~ ('oJ '<I: S 0; cO <0 c: <') (') (') ~ ""iii ~ a 0 a - 0 .l!! a a a I- !-S .... .... .... 0 (') (') (') <Il - (j) ~ (') ('oJ ~ <Il > ~ E- E c: <Il 0 m .5 ~ U ~ ~ 1ii <Il ~ " c: (j) ~ ~ ::l 0 0 ,..., (1 Figure 3: CROSS-SECTIONS Roaring Fork River at Joy Property Based on field survey of 17 September 2001 by High Country Engineering CROSS-SECTION 1, Upstream Property Line (HEC Sta. 3) 7775 7770 7765 5 7760 :::: '" 7755 ii u:; 7750 7745 7740 7735 o ~ -. / / / / "!. ~ I~ 50 100 150 200 250 Distance, feet CROSS-SECTION 2, Midpoint of Property (HEC Sta. 2) 7770 7765 7760 c 0 7755 :::: '" ii 7750 u:; 7745 7740 ,/ / / - '/ ~ 1 . ........ .~ 7735 o 20 40 60 60 100 120 140 160 160 200 Distance, feet CROSS-SECTION 3, Downstream Property Line (HEC Sta. 1) 7770 7765 7760 c 0 7755 ~ > 7750 " u:; 7745 7740 7735 o .. V / / 1/ .. . ~ 20 40 60 60 100 120 140 160 Distance, feet 1""'\ () Figure 4: APPROXIMATIQN OF CH.4.NGgS to CONFIGURATION OF CROSS-SECTIONS (Left bank facing downstream) Station 3 (xsec 1) Station 3, Upstream PL (xsec 1) Distance Surveyed Filled 48 0 47.99 46 ~ 54.3 46.54 " 44 55.7 46.23 46.23 0 k :;:; <Il 42 58.4 44.47 45 > ~ 1__ Su~eyed ~I .. 60.8 41.37 43 W 40 -II- Proposed 65.8 39.68 39.68 .. 73.8 39.56 38 36 0 10 20 30 40 50 60 70 80 Distance, feet Station 2 (xsec 2) Station 2, Intermediate PL (xsec 2) . Distance Surveyed Filled 48 ~ 46 ...... 0 46.48 , 25.6 46.98 " 44 32.8 45.89 45.89 0 :;:; l:--su~eYed,1 35.5 43.57 45 <Il 42 a; ___ Proposed 36.2 40.44 45 W .. 40 40 39.7 39.7 ........ 46.2 38.64 38 -.... 57.8 38.8 65.8 38.2 36 0 10 20 30 40 50 60 70 80 Distance, feet Station 1 (xsec 3) Station 1, Downstream PL (xsec 3) Distance Surveved Filled 48 0 43.8 46 . 26.3 41.75 41.75 ,,44 29.4 40.84 41.75 0 ~ --- :;:; l--su~eyed,l 31.1 38.78 40.6 <Il 42 a; ~ ____ Proposed 35 38.5 38.5 W 40 39 38.2 ~ 47.3 37.83 38 59.8 37.63 36 0 10 20 30 40 50 60 70 80 Distance, feet ~ ' I"". ",...." 1 , r..r;;;pJr\( ('! b!iac~ '1(:sovl3\;~ ,C(lv"t DEPARTMENT OFTHE ARMY U.S. ARMY E'J8iNEER DISTRICT, SACRAMENTO CORPS OF ENGINEERS 1325 J STREET SACRAMENTO, CALIFORNIA 95814-2922 November 15, 2001 REPLYTO ATTENTION OF Regulatory Branch (200175496) ~ william and Sara Joy 1150 River Drive Aspen, Colorado 81611 Dear Mr. and MrS. Joy: We are responding to your request, Elub:miti:ed by Beach Environmental, for a Department of the Army permit to perform streambank stabilization on approximately 300 linear feet of the Roaring Fork River. The project is located just below the confluence of the Roaring Fork River and Castle Creek within the SW 1/4 of Section 1, Township 10 south, Range 85 West, Pitkin County, Colorado. The Chief of Engineers has issued nationwide general permit number 13 which authorizes the discharge of dredged or fill material in waters of the United States for bank stabilization. We have determined that your project will not affect threatened or endangered species protected by the Endangered Species Act. Your project can be constructed under this authority provided the work meets the conditions listed on the enclosed information sheets. You must send a signed letter of certification to the Corps of Engineers within 30 days after completion of the work (see general condition number 14). A copy of the certification statement is included for your use. This verification is valid until ~bruary 11, 2002. If you have not completed your project by that time, you should contact the corps of Engineers to obtain information on any changes which may have occurred to" the nationwicte permits. Ybuare responsible for remaining informed of such changes and for ensuring that all contract personnel are familiar with the terms and conditions of this permit. .\1 ~ .~,.. " i .... ^ l'. , l -2- We have assigned number 200175496 to your project. Please refer to this number in any correspondence with this office. If you have any questions, please contact Mr. Randy Snyder of this office or telephone number (970) 243-1199, extension 12. ~ ------ Ke son ChI f, olorado/Gunnison Basin , Re atory Office 402 Rood Avenue, Room 142 Grand Junction, Colorado 81501-2563 Enclosures copies Furnished: Mr. Gary Beach, Beach Environmental, street, suite 304, Aspen, Colorado Pitkin County, 506 East Main street, LLC, 715 West Main 81611 Aspen, Colorado 81611 APR-11-2002 07:50 FROM: ,.~ r"1 .a:83-9205439 ,c._"" P.001/012 Beach Environmental. LLC 7lS W. Main S....;104 Mpen. CO 81611 ~.I (910) 925-3475 fCIX 925--4754 LETTER OF TRANSMITtAL TO: Fred Jarman City of Aspen - Comm Dev 130 S. Galena StTeet Aspen, CO 81611 FAX... q2/)- ~4 3'7 FM: Gary Beach RE: Joy Streambank Stabilization DATE: Aprill!, 2002 ~b,; tb<e 1<:> -rH1!! INFO You Y'i u.e:,,j..,J 'j;' ~1nU a... G,1le ()~ <;'t.Y' \LIW,- o~. ~ ~ '$\-k.. ~e,,>-brd~ ~ ~ Ii\of<~....ik Ci.vu ux. M( ~ ~ 111~-,t- \~ - We. sWeJ '& ~l~-k wH~ fu ~~ WQ1.l ~ 2.-5 J~., Sd ~ ~ tills wlL~ ~_ 1, Please call 925.3475 with any questions about this transmittal. Beach 715 West Main Street Suite 304 Aspen, Colorado 970.925.3475 APR-11-2002 07:50 FROM: "....., ~:83-9205439 P.002/012 To: Fll..E PM: KKM Date: 2/02 Re: Joy Streambank I spoke with Steve Ellspermann and asked if we needed to seeure any tree removing permirs. if in case we rhought we would have to. He said thar so long as the tree is under 6 inches in diameter all we had to do was call him a couple of weeks in advance and have him view the property and mark the tree. As it tums OUl. I do not think that any trees will need to be removed. 0269 -"Ole.doc o ~:83-921215439 Q P.12I1213/0l2 RPR-11-21211212 1217:5121 FROM: ,.,......, o;?,ifi R1iPI.VTO ^TTIf'l"ON OF DEPARTMENT OF THE ARMY u.s. ARMY ENGINEER DiSTRICT, SACRAMENTO CORPS OF ENGINEERS 1'125 J STREe'l" SACRAMENTO. CAUFORNIA 95814-2922 February 25, 2002 Regulatory Br~nch (200175496) Mr. william and Sara Joy u50 River Drive Aspen, Colorado 81611 Dear Mr. and Mrs. Joy: We have ex.tended the.coll.~tructir:.::tl.l?eriodund.er grandfather _ -":prOvts'j,ons'~ -e~p~rd*'9-n~..-i.de:,'De,pa.,:r::meri.t..: .~L th~_~.llJY~ p~.:.;:mi t number 200175496 to February 11, 2003. All other conditions of . the permit remain in full force and effect. ""'!_ n----- If yoU h~ve any questions, please write to Mr. Mark Gilfillan, colorado/Gunnison Basin Regulatory Office, 402 Rood Avenue, RoolTl 142, or telephone (970) 243-1199, extension 15. Sincerely, Ken Jacobson Chief, Colorado/Gunnison Basin RegulatOry Office 402 Rood Avenue, Room 142 Grand Junctiotl, colorado 61501-2563 Copies Furnished: ._. /Mr. Gary Beach, Beach Resource Management, LLC, 715 West Main . .--V-...:.-stre-et-;-.-S"'...-t.....aO.4,. ASr;len,__.Colo.J::acl9 81611 Pitkin County, 506 East Main Street,' Asperi,-.Coloracro--S.:r6'IT-"-----.- RPR-11-2002 07:50 FROM: .tI'""'\ TO: 83-9205439 f1 P.006/012 INTEROFFICE MEMORANDUM TO: FROM, SUBJBC1:, DATE: CC: GLB llT.P JOY I'T.OOiJPI.AIN REPORT OC'l'OllER 22, 21K)1 Gary" Nick Adell. City Engineer, called tills .fternoon to ;nfoIil'lllS that the ~eccntly submitted r<Fort on the Joy Floodplain satisfies all his concerns, According to his dirCoetiOll the next step would be to notify the COE of our intctltiOfl of work. Thc City will then verify compliance when the work has beeD completed. 02f,?Meh floWpliUn ~pon8C.I0-.22_01.dol;: RPR-11-2002 07:50 FROM: (\, TO: 83-9205439 ~ The AspeMnslitUle Aspen Meadows P.007/012 -- _.. J ~ Z RPR-11-2002 07:51 FROM: Beach ,.~ ~ TO: 83-9205439 t""'\ ;} 0. ~ ori~,~"-I Wl-IM'(.d lol-z./o( 01-"" P.008/012 o 4. Resource Management. I..I..C 'f1~ W MaIn Suite 304 A:opl:::I,.C.U81611 T~ (970) 92S-347S F"x ()1'i 47'54 Nick Adeh City Engineer City of Aspen 130 South Galena St Aspen, CO 81611 Re: Joy Streambank. Stabilization Project Aspen, CO Dear Nick: At your request we have undertaken and completed a flood profile analysis of the Roaring Fork River at tho William and Sara Joy property near the northwest city limits of Aspen, Colorado. The Roaring Fork River along the Joy property was surveyed by High Country Engineering on September 17, 2001 and cross. sections developed through the survey were used in a HEC-RAS computer model to deteOTline the changes in flood elevation that would result from the proposed streambank stabilization of the loft bank of the Roaring Fork River adjacent to the Joy prOperty. To paraphrase the conclu~ons of this study and report, the proposed placement of 90 cubic yards of material a1cmg this bankwill hnvean almost imperceptible effect on the stream's water surface eley~tion. In fact, in ortler to produce a measurable result it was necessary to calculate the surface water elevation change on a ten-year event. It is the engineer's opinion therefore that the results of this study iric.Ucate the addman of 90 cubic yards of flU through this reach of theri ver willhaveanrnconscqucntliilliiipaet and is likely to be sim.i1ar to the Impact Created by such natural phenomena as waves and floating debris. Therefore, we believe that the City of Aspen can now move forward with the issuance of a pennit to allow the stream hank stabilization project to proceed. Should you have any questions regarding the REC study please feel free to give me a call. Sincerely, wI attachment Cc: S. Broderick 0269 1..lreauw:wlutabilizolWn. 100lO I ;,Ii APR-11-2002 07:51 FROM: f",. 6 TO: 83-9205439 t"""" '0:) P.009/012 Subject: Date: Man, 30 Apr200116:02:09 .0600 From: Richard Goulding <rlchardg@cLaspen.co.us> To: jorine@bcachresource,com Jorine, Attach~d is the official response of the Engineering P~partm~nt in relation to cne proposed Bank SCabiliz~tion. Sorry about the delay getting this to you today but I wanted to talk to the Army Corps. of Engineers first. t was informed that n~w regional conditions have recQntly been put ia place ,eor more &ensitive.: ri.vcrs such as the Roa.ring Fork, also tha:y would like to be informed of ~uch projects 6n the Roaring Fork even though it falls within the 500ft limit. If you have further questions please contact me at 970 920 5087 or richardg~ci.aspen.co.us , Richard Goulding I_.,__..,,",~ , Name: ]oybankstablisation.doe DJoybankstablisation.doc Type: WINWORD File (application/msword) Encoding: base64 , ... maV{ h.ctve. (l<:,~ Y<=3IOYlq I ~r+\liY'l'S . l(\D~ro...e, R. v:: 12.IWY, 30 {d n1e~ ~~a...,.J .d..:, I.) Q. V'I.+'\'" '=.. ""'" +,'{\~ ~ K\lG.(,. Gt~" ~\JJf...:ll: ~', ~;-k \-oc.~ .m..~_ 1 of! 413010.) 5:4'> PM .. APR-11-2002 07:51 FROM: f""'\, o .", TO: 83-9205439 t"'\ '0 P.010/012 DRe Joy Slope Stabilization Memo Ref: 1250 Riverside Drive, Aspen Date: April 30,2001 The submittal need to include a report by a licensed professional engineCl'registered in the state of Colorado with experience in the field of river hydrology/ channel stabilization. The submittal must include the following professional level work: 1) Completion of a survey of the cross sectioning of the existing and proposed river channel 2) Performing a HEC- 2 run/analysis to ensure to ensure no rise or spread of flood flows beyond floodplain boundaries established by FEMA in the June 1973 Publication. 3) Meet the regional conditions from the Army COIp. of Engineers and inform them of the project if a Nationwide Pemlit#13 Bank Stabilization is to be used. We are asking for the above so as to avoid any damage to up, down stream or adjacent properties and to safeguard against future related problems. o TO: 83-9205439 ra P. 011 /012 APR-11-2002 07:52 FROM: ^ ~~ Beach Environmental. LLC Steven EL~perman City Of Aspen 130 S. Galena Aspen, CoJot'~do 81611 April 6, 200t Dcal Steven ElspCLman, JOY STREAMBANK STABIliZATION As you rcqucsted, 1 am submitti.ng the site plan and report for the JoY stteambank stabilization project. We are requesting for an exemption flom the stream margin revic::w plOcesS. Please revkw and advise. Feel fj:cc to cill with any questions or if additional information is needed. SineCLe1y, ~--;r ]orinc Lawyer environmental Scientist 71~W.~1l Sulft' }04 Aspcn,C081611 Tel (970) 925--3475 ~',))( 92$-4754 . o TO: 83-9205439 n o , P.012/012 APR-11-2002 07:52 FROM: r--. ~~ ae.,ch Environmental. LLC DATE: 3/26/01 ce, FROM: RE: NlCKlJ'..lJ\CK. C'fJYPIJ\NNF.R GAIlY I:lt:A.Ct1, TAItt. MCC\.lWAN ]ORINn I.AWYER JOY ~;TIU::AMllANl< STAIlIUZATION ~to: r have a([ached this memo .. a supplement [0 our report to highlight the Joy Srreambank Stabilizatioa project on the Roaring Fork River. Plea,e view our ,ite pl.n as . supplement to this memo. The Joy's pleseady own two propemes .dj.eent to the Roaring Fork River on 1150 River Drive in the Gty of A,pen. Cur<elltly the stl'ellmbank lllong their prope'ty is protee,ed by a long wckw-.ill, boulders, and felled tree,. '1'hi, protection has o.ged, and d,e hydr.ulie force, of tho rivcr arc eroding the';" property. Beach Environmentol WAS 'erained by the Joys to construct .n cnvironment:llly sensitive design that would both stabilize the banks while ""hancing habitat and s",eam .esthetics. Ou, designs incorpomte bioengineering, which uses narive pl.nr roaterials above the high w.= line fOI st"J.biliz2tiOn. Below rhehigh water line) we will be using.stone-r.oe pmtccrioll. 'This is similar to what is presently on-site, but We!: will use a geotextilc mctlh behind the stone to limit erosiOtl oC silt and other fine material Coir logs, and bouldcr clusters are also part of our protection design_ Details of e<lch of these techniques c..n be found in figures 3-6. This projcct is ,moll in ,cole; approximately 30() fect of streambank arc sited for ,tabili:.atioll. We have aL:cady been approved for a Nationwide 'Permit No. H from the Army Corp' of Enjl;ineeJ:s for this project and m.eet all of lheir gene~l and specifk conditions. See attached .report for details. Weare asl;ing the Gty of Aspen for two thing~; 1) Approval ,or lhe ptoject as is. What is the p.rOcess and wnefr.me for approval? What additional information i. required? 2) What pomon. of our pwposal need to be removed, if any, if we wnuld like tn expedite thc process and qualify for an exemption? 0269:n.03 11) Vv fI.'L....ln ~\fil<; ~ln..l 1 '\~''''''I).(''U~ll.Ill Tel (C)10) <'n:S--3415 r.t)!: 9"", 47....~ ~, n MEMORANDUM To: Fred Jarman, Planner From: Richard Goulding, Project Engineer Date: May 25, 2001 Re: Joy Stream Meeting Attendance: Nick Adeh, Fred Jarman, Gary Beach, Richard Goulding On Thursday, May 24, 2001 Gary Beach met with the City Engineer, Nick Adeh to discuss the requirements for stabilizing the Joy stream bank. The following conditions are to be met to ensure approval from the engineering department: 1) Completion of a survey of the cross sectioning of the existing and proposed river channel, using 3 sections and is to be stamped by a licensed surveyor in the state of Colorado 2) A letter from a professional engineer registered in Colorado stating that no upstream or downstream degradation will result from the proposed development 3) AJeHel 110m WilKe Cloffy at th" Armv Core of Engineers approving the work