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HomeMy WebLinkAboutcoa.lu.sm.Aspen Art Museum.590 N Mill St.030A-84 '� =7 9V CASELOAD SUMMARY SHEET // �� City of Aspen a - ` 3 - 0'4 3-a o " 0 CASE NO. ' n , 304 ' O y /� n �yy&-:2� /��� � STAFF: � / 2,4r -:t � U -�l#C- /!/� '� I PROJECT NAME: n" �� &4 � /,( /, E 72.�I�G nn • U'2i L- /14r A PL (.1 APPLICANT: ( 1 .rr�„c, £t t L / P �'k'y4 ;Ai J / / Phone: `_ (� ��- ,yv/\ REPRESENTATIVE: C/ U [ /IbC/�- c-�'J T �-- Phone: i9 TYPE OF APPLICATION: 650 At 1 kA IL L Sr (FEE) I. GMP /SUBDIVISION /PUD (4 step) _ 1. Conceptual Submission • ($2,730.00) , _ 2. Preliminary Plat ($1,640.00) • 3. Final Plat ($ 820.00) II. SUBDIVISION /PUD (4 st ) _ 1.-j Conceptual Submi- ion ($1,900.00) 2. Preliminary Plat ($1,220.00) 3. Final Plat ($ 820.00) ____ III. EXCEPTION /EXEMPTION /REZONING (2 step) ($1,490.00) \/ IV. SPECIAL REVIEW (1 step) ,� / ,S�",6,,@O -DDf N i 1. Special Review lea. , i ML4 i (f IC W 2, Use Determination �/ 3. Conditional Use , 4. Other: P & MEETIN DATE: L'C b CC MEETING DATE: DATE REFERRED: 9/' 74 n �Kz -�¢Fc etD S) /a /a7/61/ REF / E / RRALS : Fi V pity Attorney Aspen Consol. S.D. _ School District City Engineer Mountain Bell — Rocky Mtn. Natural Gas Housing Director _ Parks Dept. _ State Hwy Dept. (Glenwood) Aspen Water Dept. _ Holy Cr s Electric _ State Hwy Dept. (Grd. Jctn) ity Electric O /C, _Fire Ma hall _Building Dept. �/ Environmental Hlth. Fire Ch f Other: FINAL ROUTING: DATE ROUTED: I ` N -0 ,�ity Attorney City Engineer Building D dp S ✓ Other: (2I . 1 _ . . /" -1 I . :, ;i :' r ---- Other: 0 11 FILE STATUS AND LOCATION: (} & b-O - / ...IPOSITION: e --- i ...„,, CITY P&Z REVIEW: Li 1,,, A,/ , -, p ,- i , , ., t ......,,, , . , , . , . , I.. , ,...c,\7( 1, -'" '" { . l f ) 1 1 .. Q _ I_ - i it 9 ,), lor I" Olt n i - J\ --' )(I /co lt ,,, • Ad - 1*., ' 1; I -, ! L- __ I -,,t, r ; , 1 , - 1 / , r f i}- m . „, I \I, (' : I A 2 , 1 -- t ' C ' r‘- ' ' • , .. 1 7 1 ' 1 I , 1 I I ' .c 1L •C: k I i ; I ; . 1 I • 1 • t i -J ' ' , -) 1 -- - a i ' i 1 • .- /J-{ a 1 4 t_C ir.:; , lir tt eaefr-eetyttett—fteittt-- ( , , 2/735 24 , r )/r( i '' / 7-1-- I : - ' 7 Ali 4 ' . / I 1 I --- flr" l) VInsc)") / K 1 1 2 I 4 /2,41 i fri 1 j Le d , ) I —L i /jr. / i () 7 ,,,,. i ( h 1 ri ''- 41: )-( 1 IN • ' ' 1 4 1 ) L'n PI -,,, // 7 >, )... (....) L , k), l n , ' / ' i /1 I -:', Li' )--e/iVeni 0 , i , 1 1 i 1 A. ) f ' /t , k___ ,-/ i, i‘ ,),. , i .), / (7 // , „, „) ,- 1 , ir , , 6 , A ,,,.///,/ , ,,,, ,) , p es 7 /)Prdinance No. CITY P&Z REVIEW: (1 ee l CITY COUNCIL REVIEW: Ordinance No. CITY P&Z REVIEW: - --- CITY COUNCIL REVIEW: -11 Ordinance No. _ _ MEMORANDUM TO: Aspen Planning and Zoning Commission FROM: Colette Penne, Planning Office RE: Aspen Art Museum - Stream Margin Review DATE: February 5, 1985 You have reviewed proposals on several occasions which dealt with various aspects of channel widening in the Roaring Fork River at the Aspen Art Museum. Phase I of the proposed work has been approved by you and includes clearing the channel of man -made fill, widening the channel, and stabilizing the bank. In addition, the temporary storage of the excavated material has been approved under the agreement that the material will be renoved by October 1, 1985, and the area will be reseeded with a native grass and wildflower mixture. The request before you tonight is for channel improvements approximately 800 feet upstream from the Art Museum. The location is the Oklahoma Flats properties which have experienced flooding problems in the past, and were unable to respond without stream margin review approvals. These property owners have approached the City to do channel improvements in their location and at their expense. The work to be done will be the removal of two boulders, a large slab of concrete and a portion of concrete bank. The portion of the concrete bank to be removed is ten to fifteen feet wide by thirty to forty feet long, and resulted from the dumping of excess concrete by a batch plant that was located by a bend in the river at Spring Street. Removal of this section will clear the channel and make room for the increased spring runoff. Removal of the boulders and the concrete will require blasting and a D -8 Catepillar track loader will have to work in the river to remove the materials. The work is estimated to take a day and a half to complete. This improvement to the stream channel and its capacity is for the purpose of reducing a flood hazard. Removal of the concrete will also enhance the stream's value as a natural feature. PLANNING OFFICE RECOMMENDATION: The Planning Office recommends Stream Margin Review approval for the channel and streambank clearing proposed in this application. Ce /u ned 7±4 Cz v GZ z 49 L cice-. n, /Z: 62 / 7 am' k E cr�� -rj— CITY OF F ASPEN 130 south galena street aspen, colorado 81611 303- 925 =2020 ciP - FSU.RTJI AMENDMENT STREAM MARGIN REVIEW APPLICATION ASPEN ART MUSEUM FLOOD CONTROL - PHASE I December 12,. 1984 Planning and Zoning Commission City of Aspen 130 South Galena Street Aspen, Colorado 81611 Ladies and Gentlemen: This letter constitutes the fotmtn amendment to the City of Aspen application of September 26, 1984, for permission to widen the channel of the Roaring Fork River across from the Aspen Art Museum. The City has received requests from Oklahoma Flats property owners to perform channel improvements in their vicinity and at their expense. The City is amenable to this request and indeed our original channel widening design took into account some mitigation of flooding impacts in that area, which is only some eight hundred feet upstream of the Art Museum. Therefore, we request your permission to remove two boulders, a large hunk of concrete and a portion of concrete bank as shown on the revised development plan. The boulders and concrete hunk are three to four cubic yards in size, or about five tons each. About twenty years ago, there was a concrete batch plant located at the bend in the river by Spring Street. A portion of the bank there now is solid concrete as a result of the plant dumping excess concrete. We would like to remove the boulder, concrete hunk and a portion of the concrete bank about ten to fifteen feet wide by thirty to forty feet long in order to clear the channel at that point and to provide more room for the passage of spring runoff flood waters. In order to do this, we will have to perform blasting to break off the bank and to reduce the size of the boulders. Then we will have to work in the river with a D -8 Caterpillar Page Two Aspen Art Museum Flood Control - Phase I Planning and Zoning Commission track loader to remove the materials. We may also scrape a cobble bar on the inside of the river bend up onto the Volk/ Reich property, again to provide a larger channel capacity at that point. I have checked with the Army Corps of Engineers, the State Water Quality Control Division and the State Wildlife Division. None of those agencies has any objections to this proposed work, nor are we required by any state statute to obtain permits for dredging. It is only the discharge of materials into waterways which is regulated. This work is estimated to require a day and a half, so we will not be in the river for long. We request your approval of this new phase of our channel improvement and floodplain mitigation project. Thank you for your time and consideration. Sincerely, t/ Chuck Roth Engineering Department CR /co MEMORANDUM TO: City Attorney City Engineer Environmental Health FROM: Colette Penne, Planning Office RE: Aspen Art Museum Stream Margin Review Case No. 030A -84 - Re- Referral DATE: December 27, 1984 Attached is an application submitted by the City of Aspen Engineering Department requesting stream margin review for work to be performed within the stream margin at the Aspen Art Museum. This is the fifth amendment to the application reviewed by you previously. Please review the material and return your referral comments to the Planning Office no later than January 22, 1985 in order for this office to have adequate time to prepare for its presentation before P &Z on February 5th. Thank you. MEMORANDUM r i ' 1 r 2 ` r '1 E TO: at Guyer Environmental Health FROM: Colette Penne, Planning Office RE: Aspen Art Museum Stream Margin Review Case No. 030A -84 - Re- Referral DATE: December 27, 1984 Attached is an application submitted by the City of Aspen Engineering Department requesting stream margin review for work to be performed within the stream margin at the Aspen Art Museum. This is the fifth amendment to the application reviewed by you previously. Please review the material and return your referral comments to the Planning Office no later than January 22, 1985 in order for this office to have adequate time to prepare for its presentat on b fore P &Z on February 5th. Thank you. 1 l-q CIT ,r SPEN 130 . " • reet asp. 611 FOURTH AMENDMENT STREAM MARGIN REVIEW APPLICATION ASPEN ART MUSEUM FLOOD CONTROL - PHASE I November 14, 1984 Planning and Zoning Commission City of Aspen 130 South Galena Street Aspen, Colorado 81611 Ladies and Gentlemen: This letter constitutes the fourth amendment to the City of Aspen application of September 26, 1984, for permission to widen the channel of the Roaring Fork River across from the Aspen Art Museum. At your meeting of November 6, you denied the permission requested in the Third Amendment to place any of the excavated materials within 100 feet of the high water line of the Roaring Fork River and further expressed disapproval of Council's directive to place the excavated materials on other portions of the Rio Grande Property because of the Specially Planned Area zoninc designation. Your points are well made. At the Council meeting of November 12, the Council directed the Engineering Department to pursue the excavation and because of the emergency nature and public protection nature of the project, to temporarily store the excavated materials on the Rio Grande property. The Streets Department would be able to remove these tempo- rarily stored materials from the property by the end of next summer. I have been to the site with the street superintendent, and he has . Wt _s�iew�d one where we could place these excavated materials. I staked a line 100 feet from the high water line of the river, and it leaves us with 7,500 square feet to use versus 25,000 square feet if we can temporarily store up to ten feet from the river. Storing four thousand cubic yards on 25,000 square feet of land would result in four and a half feet high of material. Please see the attached map. There is little existing vegetation on the proposed site except for , grass and weeds. There are some large cottonwood trees, but we would not touch them with our temporarily stored materials. Page 2 Aspen Art Museum Stream Margin Review November 14, 1984 We are working on an emergency basis to protect public property, and we urgently request permission to store the excavated materials temporarily in the area shown on the map. The material will be removed from this area by October 1, 1985, and the area will be reseeded with a native grass and wildflower mixture. Thank you for your consideration. Sincerely, d‘c‘ Chuck Roth Engineering Department § Pat)? f ; ,, ;`i 130 C e 4 i f , a sp. y 1 1 I "' ! THIRD AMENDMENT STREAM MARGIN REVIEW APPLICATI ASPEN ART MUSEUM FLOOD CONTROL - PH November 5, 1984 Planning and Zoning Commission City of Aspen 130 South Galena Street Aspen, Colorado 81611 Ladies and Gentlemen: This letter constitu the third amendment to the City of Aspen application of September 26, 1984, for permission to widen the channel of the Roaring Fork River across from the Aspen Art Museum. At the City Council meeting of October 22, 1984, the Engineering Department was directed to place the excavated materials on the city - owned Rio Grande property. A portion of the property to be filled is within one hundred feet of the high water line of the river and therefore is also addressable under stream margin review criteria. We have also been directed to relocate the Rio Grande trail to along- side the river. We anticipate raising the entire level of the snowdump by one and a half feet as well as the Rio Grande property up to the Obermeyer and Welding Company buildings. Since our goal is to widen the river, we are not of course going to be placing any of the excavated materials where it will affect the river! But we do need permission for the portion of the fill that we will be creating within one hundred feet of the high water line. We request that you approve this new portion of the project. Thank you for your time and consideration. Sincerely, Chuck Roth Engineering Department n MEMORANDUM TO: Aspen Planning and Zoning Commission FROM: Jay Hammond, City Engineer jk" RE, Roaring Fork Fill Removal • DATE: November 16, 1984 At your meeting on November 6, 1984, you approved an application submitted by the City of Aspen to do work on the stream channel of the Roaring Fork River above the Aspen Art Museum. The application was amended just prior to the meeting to include depositing the fill to be removed on the Rio Grande property. You denied the request to put the fill on the Rio Grande because you did' not have information on where it would be placed, at what depths and whether or not it would be landscaped. Also, the Rio Grande property is an SPA, and it had yet to be determined if this use would require an amendment of the SPA plan. Council decided at their meeting of November 12, 1984, to undertake the fill removal along the river and to place the material on the southeast corner of the snowdump where it is to be stored temporarily pending either adoption of an SPA for the area utilizing the soil or complete removal of the stockpile by the end of next summer. We are currently proceeding with the fill removal and temporary stockpiling in order to deal with the public safety issue and to stay ahead of the winter weather. It is our feeling that the temporary placement of this material is generally in keeping with stream margin criteria and still leaves considerable flexibility in terms of future use of the Rio Grande. It is also worth noting that the fill mate; ial is of a considerably better quality than we had anticipated. In terms of Strewn Iiargin criteria, I would address the following points: • 1. No structures or fill will be placed within the 100 -year fl oo dpl ai n. 2. Our grading will accommodate a rivers -edge trail. 3. We are not, at this time, implementing the Roaring Fork Greenway Plan, however, subsequent to the later removal of the material, the area will be reseeded with native riparian vegetation. 4. Vegetation removal is limited to grasses and bushes in the excavated area. The stockpile area will not violate several existing cottonwoods. Erosion of the channel will actually be reduced by this work. 5. We are increasing the channel capacity and will not be working in the river itself in a manner that would increase suspension loads. 6. This excavation represents the first step in a major program to enhance the river capacity and environment in the area of the Rio Grande and Aspen One. With respect to SPA concerns, it is Paul Taddune's interpretation that • temporary storage of fill does not constitute development of the property. It is our intention to remove or redistribute the fill in keeping with an adopted SPA plan by October 1, 1985. In the event any extension off this date is necessary, such as to accommodate adepLion of a plan in process, we will seek your approval. While we are certainly cognizant of Stream Margin concerns, as outlined above, the Engineering Department is particularly concerned over the need to address the public safety in a timely fashion. We would hope that you will bear these needs in mind when we discuss this matter on November 20th and ratify our approach. • • — 2 MEMORANDUM TO: Aspen Planning and Zoning Commission FROM: Colette Penne, Planning Office RE: Aspen Art Museum - Stream Margin Review DATE: November 6, 1984 The City Engineering Department is proposing work on the channel and the stream bank of the Roaring Fork River in the area of the Aspen Art Museum. During last year's spring runoff, the bank broke down and an emergency effort was undertaken to save the Art Museum from being flooded. This work is proposed to stabilize the bank, clear the channel of man -made fill which has been introduced, and widen the channel. This review is for the first phase of work as outlined above and in the attached application from the Engineering Department. The second phase will involve permanent repair of the stream bank and revegeta- tion. That work will be the topic of an additional Stream Margin Review application. The review criteria for Stream Margin Review are as follows (Section 24- 6.3(c)]: (1) No building shall be located so as to be within a flood hazard area designated by the U.S. Corps of Engineers Flood Plain Report for the Roaring Fork River. (2) In the event there is a trail designated by an approved trail plan within the development site, such trail shall be dedicated for public use. (3) All attempts should be made to implement the recommendations of the Roaring Fork Greenway Plan prepared by the Roaring Fork Greenway Committee. (4) Vegetation shall not be removed nor any slope grade changes made that may produce erosion of the stream bank. (5) There shall be permitted no changes to the stream channel or its capacity, and no activity shall be allowed which will increase stream sedimentation and suspension loads. (6) All efforts must be made to reduce stream pollution and interference with the natural changes of the stream, and to enhance the value of the stream as an important natural feature. The Environmental Health Department stressed in their referral comments that "precautions be taken to hold to an absolute minimum the amount of sediment entering the Roaring Fork River during the construction phase of this project." The Engineering Department has outlined in detail the reasons for doing this work and the techniques to be used for correcting existing channel problems. As you may recall, this past spring's runoff seriously threatened the Aspen Art Museum. The bank in front of the building totally destabilized and the proposal is to widen the channel to accommodate the level of spring runoff and reduce the force of the stream on the bank. In terms of the review criteria, the following information is offered: (1) No building is being constructed. (2) There is no trail designated within the development site. (3) Upon completion of excavation, the area will be reseeded with native grasses and wildflowers in accordance with the Roaring Fork Greenway Plan. (4) The flooding event in June resulted in damage to the bank such that cottonwood trees fell into the river. This phase of the work proposes a dike /levee along the length of the bank to help save the cottonwoods and willows along the river. The grades will be the same as those existing, but will be moved away from the channel. (5) The purpose of this work is to alter the stream channel so that man -made fill is removed and detrimental changes to the channel and its capacity are corrected. Since these are recognized as improvements by the Army Corps of Engineers, a permit is not required. There will be no work done in the stream bed and therefore, no disturbance to it or sediments added to the water. When the new channel fills during spring runoff, sediments will be added but because of high levels of sedimentation at that time, effects will be minimal. (6) The proposed work is moving in the direction of restoring the river to its natural channel configuration. Man -made fill is being removed and pollution will not be added to the stream. The Engineering Department will be present at the review to detail the work and site plan and answer your questions. At your meeting of October 16, 1984, you tabled action on this request because information was not available on the downstream effects of this work. Of particular concern was the next constriction in the stream channel, which is the site of the Andrews - McFarlin buildings. Attached to this memorandum is the Engineering Department's report on their calculations of the effect of the work on the river flow. The calculations were performed by both the City Engineering Department and the Denver Engineering Corporation. The result was that the river would return to its natural state approximately 200 feet downstream from the work. The Andrews - McFarlin buildings are 400 feet from the area where the work is proposed to be done. PLANNING OFFICE RECOMMENDATION The Planning Office recommends approval of Stream Margin Review for the City to complete Phase i of the work on the Roaring Fork River at the Aspen Art Museum as proposed. - 2 - CIT , r, ,.�,: SPEN 130 . ±� -� . = reet asp 611 October 23, 1984 Planning and Zoning Commission City of Aspen 130 South Galena Street Aspen, Colorado 81611 RE: Stream Margin Review - Aspen Art Museum Ladies and Gemtlemen: This letter is written in response to your concern regarding the effects of our proposed channel widening at the Aspen Art Museum on the downstream neighbor, the Andrews McFarlin Condominiums. The Engineering Department performed calculations which showed that the river flow would return to its natural state in a distance of from 150 feet to 250 feet downstream from the end of our work. The Andrews McFarlin Condominiums are located 400 feet downstream from the end of the work. I also called Denver Engineering Corporation for their analysis of the question.That company recently completed a new floodplain study of the City of Aspen under contract by the Federal Emergency Manage- ment Agency. Their hydraulics engineer confirmed that the flow of the river would return to its natural conditions within about two hundred feet downstream from the end of our work. The city would appreciate your earliest approval of this application so that we may commence work as soon as possible. Thank you. Sincerely, ativ ski Chuck Roth Engineering Department MEMORANDUM TO: Aspen Planning and Zoning Commission FROM: Colette Penne, Planning Office RE: Aspen Art Museum - Stream Margin Review DATE: October 16, 1984 The City Engineering Department is proposing work on the channel and the stream bank of the Roaring Fork River in the area of the Aspen Art Museum. During last year's spring runoff, the bank broke down and an emergency effort was undertaken to save the Art Museum from being flooded. This work is proposed to stabilize the bank, clear the channel of man -made fill which has been introduced, and widen the channel. This review is for the first phase of work as outlined above and in the attached application from the Engineering Department. The second phase will involve permanent repair of the stream bank and revegeta- tion. That work will be the topic of an additional Stream Margin Review application. The review criteria for Stream Margin Review are as follows [Section 24- 6.3(c)]: (1) No building shall be located so as to be within a flood hazard area designated by the U.S. Corps of Engineers Flood Plain Report for the Roaring Fork River. (2) In the event there is a trail designated by an approved trail plan within the development site, such trail shall be dedicated for public use. (3) All attempts should be made to implement the recommendations of the Roaring Fork Greenway Plan prepared by the Roaring Fork Greenway Committee. (4) Vegetation shall not be removed nor any slope grade changes made that may produce erosion of the stream bank. (5) There shall be permitted no changes to the stream channel or its capacity, and no activity shall be allowed which will increase stream sedimentation and suspension loads. (6) All efforts must be made to reduce stream pollution and interference with the natural changes of the stream, and to enhance the value of the stream as an important natural feature. The Environmental Health Department stressed in their referral comments that "precautions be taken to hold to an absolute minimum the amount of sediment entering the Roaring Fork River during the construction phase of this project." The Engineering Department has outlined in detail the reasons for doing this work and the techniques to be used for correcting existing channel problems. As you may recall, this past spring's runoff seriously threatened the Aspen Art Museum. The bank in front of the building totally destabilized and the proposal is to widen the channel to accommodate the level of spring runoff and reduce the force of the stream on the bank. In terms of the review criteria, the following information is offered: (1) No building is being constructed. (2) There is no trail designated within the development site. (3) Upon completion of excavation, the area will be reseeded with native grasses and wildflowers in accordance with the Roaring Fork Greenway Plan. (4) The flooding event in June resulted in damage to the bank such that cottonwood trees fell into the river. This phase of the work proposes a dike /levee along the length of the bank to help save the cottonwoods and willows along the river. The grades will be the same as those existing, but will be moved away from the channel. (5) The purpose of this work is to alter the stream channel so that man -made fill is removed and detrimental changes to the channel and its capacity are corrected. Since these are recognized as improvements by the Army Corps of Engineers, a permit is not required. There will be no work done in the stream bed and therefore, no disturbance to it or sediments added to the water. When the new channel fills during spring runoff, sediments will be added but because of high levels of sedimentation at that time, effects will be minimal. (6) The proposed work is moving in the direction of restoring the river to its natural channel configuration. Man -made fill is being removed and pollution will not be added to the stream. The Engineering Department will be present at the review to detail the work and site plan and answer your questions. PLANNING OFFICE RECOMMENDATION The Planning Office recommends approval of Stream Margin Review for the City to complete Phase i of the work on the Roaring Fork River at the Aspen Art Museum as proposed. - 2 ASPENOPITKIN ENVIRONMENTAL HEALTH DEPARTMENT MEMORANDUM r©.11,9„ 00 2 1984 TO: Colette Penne, Planning Office FROM: Thomas S. Dunlop, Director -1s0 Environmental Health Department DATE: October 2, 1984 RE: Aspen Art Museum Stream Margin Review Compliance with requirements listed in Section 24 -6.3 of the Aspen Municipal Code will be required of the Engineering Department. Precautions shall be taken to hold to an absolute minimum the amount of sediment entering the Roaring Fork River during the construction phase of this project. TSD /co 130 South Galena Street Aspen, Colorado 81611 303/925-2020 CIT ,it' � SPEN 130 , �• -• • reel : � asp 611 October 2, 1984 Planning and Zoning Commission City of Aspen 130 South Galena Street Aspen, Colorado 81611 RE: Stream Margin Review - Aspen Art Museum Ladies and Gentlemen: Greetings. This letter is an amendment to our application letter of September 26, and a revised development plan is attached. These are for the purpose of responding to Planning Office requests for clarif- ications of various points of the application. The development plan has been revised to include two sections. Section A -A shows how an island will be left at the tip of the snow dump, directly at the bend in the river. Note on the map attached to the letter of September 26, that there were a number of islands in the river channel in 1964. Section B -B is added to show how a dike or levee will be left along the entire length of the project. In this manner, no work will be done in the streambed. There will be no disturbance to the streambed, and there will be no sediments added to the water. At the end of the work, the "gate" shown on the plan will be cut open and some flow will be let into the new channel. Because of the low river flows at this time of year, the new channel will receive negligible water, and little or no sediments will be added at the downstream end of the new channel. It will not be until spring runoffs commence next year that the new channel will be filled. It will be at that time that sediments from the work will be generated and added to the water. However, the spring runoff waters are already high in suspended matter loads so that the increase of sediment at that time will be minimal. The City Code enumerates six items for review criteria. The following information addresses the Municipal Code, Sections 24- 6.3(c)(1) through 24- 6.3(c)(6), respectively: Page Two October 2, 1984 Stream Margin Review - Aspen Art Museum (1) This project is not constructing a building. (2) The approved trail plan does not designate a trail at this site. (3) Addressed in letter of September 26. (4) An additional function of the dike /levee will be to save existing vegetation (cottonwood trees and willows) growing along the river. The grades of the slopes will not be changed but will merely be moved away from the existing river channel and regraded to the same grades as are there now. See Sections A -A and B -B on the development plan. (5) The intent of this section is to prevent detrimental changes to the stream channel or capacity. As with the Army Corps regulations, improving a channel or its capacity ifsnot regulated. The stream sedimentation and suspension loads have been discussed above. (6) Pollution will not be added to the stream. We will not be interfering with the natural changes of the stream because what we are doing is removing man -made fill. This is being done in order to protect the art museum building from damage or destruction by spring runoff floods. We are actually working towards restoring the river to its historical channel. I hope that this letter will clarify the application. Sincerely, Chuck Roth Engineering Department CR /co /AspenArtMuseum Enclosure d MEMORANDUM TO: City Attorney City Engineer Environmental Health FROM: Colette "Penne, Planning Office RE: Aspen Art Museum Stream Margin Review DATE: September 27, 1984 Enclosed for your referral comments is an application submitted by the City Engineering Department requesting stream margin review for work to be performed within the stream margin at the Aspen Art Museum. Please review these materials and return your referral comments to the Planning Office no later than October 2, 1984, in order that the Planning Office has adequate time to prepare for its presentation before P &Z. This application is being processed expeditiously in order to complete work on the building and grounds before winter sets in. If you have any questions or problems meeting this deadline, please contact me as soon as possible. Thank you. 4 CIT . . . F, Hs SPEN 130 • reet asp, - .." 611 p, .. —, September 26, 1984 Planning and Zoning Commission City of Aspen 130 South Galena Street Aspen, Colorado 81611 RE: Stream Margin Review - Aspen Art Museum Ladies and Gemtlemen: Greetings. This letter is a request for a Stream Margin Review pursuant to Section 24 -6.3 of the Aspen Municipal Code, for the City of Aspen's flood control work to protect the Aspen Art Museum. This project is being undertaken primarily to protect the building and grounds of the city owned art museum. On June 16th of this year, the building was threatened during the height of the snowmelt runoff flood- ing. The cottonwood trees which were stabilizing the bank were under- mined and fell into the river. The bank rapidly started sluffing into the river, and a fourteen hour city- county emergency effort was required to restabilize the bank and protect the one hundred year old building. The project will be accomplished in two phases. The first phase will be to widen the existing channel as shown on the attached stream margin development plan. An additional map is attached to this letter which shows the edges of the river channel as established by a 1964 aerial photo survey as compared to the river's course established by a 1974 aerial photo survey. There has been discussion of removing the fill and returning the river to its old channel. This phase of the work will be a step in that direction. Widening the river as shown will provide a larger channel for accomodating spring runoff thereby taking much of the force off of the bank in front of the museum. The second phase of the work will be addressed in a separate application and will involve a permanent repair of the bank in front of the museum followed by cleaning that area up with resodding and replanting with trees. The city streets department will remove the fill as shown. The work will be supervised by the city engineering department. Because the Page Two Stream Margin Review - Aspen Art Museum September 26, 1984 excavation is of recently placed fill, there is no historical vegetation to preserve. There are a number of smaller cottonwood trees and willow clumps which will be preserved in the form of islands similar to those shown on the 1964 mapping of the area. Upon completion of excavation, the area will be reseeded with native grasses and wildflowers in accordance with the Roaring Fork Greenway Plan. All efforts will be made to preserve the existing water quality and not to add sediment loads to the stream. The property where the river will be widened is all currently owned by the city. Since we propose to remove materials and widen the channel, we are not required to obtain a permit from the Army Corps of Engineers. That agency is concerned with the discharge of fill or dredged materials in waterways or adjacent wetlands. The Engineering Department requests that this application be expeditiously approved so that this work can be done as soon as possible. Thank you for your consideration. Sincerely, aliaCt Chuck Roth Engineering Department P Nit AMP r 7 �.\ \ ill ���0� I �. � _ '< . V 0 zvv ,/, -\\-; i �a o'�v v 0 t � rS d � r V tit ! A l � /vy 4 � Q 4 ( . g iii -- ,-,-,AI";7:; , t; --- \ tar .--- / 0 ' t., \ N\i! a .t. * ;',,\‘ IC -6 it \ - ' /40111 fit 3 9 -� `� >/ � r \ �` I@ � .\ !�� i�/j + � lr r I \ ` ° \ ; ' li p'' a 0 � f V , k .,/„....... , \ lavx-/r/ . ?!' (0\ imeN i 1 4 4 11 ' kik ,i/SII. 4 ka i "1 V\ . r ,<, 1 \ , 1 7 I I - . . ,\ ,--4\,- k apieric . iy :. f it �A��v i N i U \ • it - -\\ \ ‘ \ \ ' 1 t ' ‘ 4 , ,__, - , , , ,,_ _4 , , , v \\ . 'N. :%.- ''‘ \ \ , it\t‘tiliX.„,,-* ' i, i t \ �/ - ‘ ,.„.__________„ _s t--, . ,\\ , ,_.„ , __ , s ,, )...„,,,-,.--, t--, .i \ '''. 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