Loading...
HomeMy WebLinkAboutcoa.lu.sm.Aspen Center for the Visual Arts.1980 MEMORANDUM TO: Aspen Planning and Zoning Commission FROM: Karen Smith, Planning Director RE: Stream Margin Review for the Aspen Center for the Visual Arts DATE: June 12, 1980 Attached to this memorandum is an application, prepared by the City Engineering Department, for stream margin approval of the proposed landscape work to be done on the old Holy Cross property, currently known as the Aspen Center for the Visual Arts. The work involves primarily the placement of shrubs, trees, top soil, sod, and seeding in the area around the old Holy Cross building, and covering the majority of the site. A more detailed descip- tion of the proposed work and construction techniques is contained both in the memorarduni from Jay Hammond, as well as in a plat showing the location of improvements, prepared by Henry Pedersen, and which will be made available at your meeting on Tuesday. The review criteria for stream margin review, pursuant to Section 24 -6.3 of the Zoning Code, include: 1. No buildings shall be located so as to be within a flood hazard area designated by the Corps of Engineers Floodplain Report. 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 made to implement the recommendations of the Roaring Fork Greenway Plan. 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 capa- city and no activity shall be allowed which will increase stream sedi- mentation. 6. All efforts must be made to reduce stream pollution and interference with natural changes of the stream. We have referred this application both to the City Parks Department and to the County Engineer, in recognition of the fact that the application was pre- pared by the City Engineering Office. The County Engineer has reviewed the application for impact on the 100 -year flood and stream channel. Based on referral comments received to date, and a review of the Roaring Fork Greenway plan, the Planning Office has the following comments to make: 1. The Holy Cross site was one identified as an important site to be acquired to promote the purposes of the Roaring Fork Greenway Plan, prepared in 1972. The acquisition of this site assures the extension of continuous stream frontage. The site is a large one protruding into the channel of the Roaring Fork River and is densely vegetated at this time. Public use and restoration of the site is encouraged by the plan and serves to complete an important linkage of greenway between areas of development on either side of the Roaring Fork River. The placement of a bridge from the Rio Grande property to the Holy Cross site assures another area of public access in a north -south direction across the Roaring Fork. This north -south link is a part of the Aspen area /Pitkin County bicycle trail system, adopted as the amended version of the Aspen area Trails Master Plan in August, 1979; the link from the pedestrian bridge to Red Mountain Road will be paved through the Holy Cross property, according to the City Engineering Department. Memo: ACVA Stream Margin Review June 12, 1980 Page Two 2. The landscaping plan proposes a variety of trees, shrubs and a combination of sodding and seeding. The tree and shrub mixture appears to be consistent with the greenway plan's designation of this area as "cottonwood /spruce ecosystem." Seeding with a mixture of native grasses is recommended to restore the natural ecosystem of the site; therefore, sodding should be limited in order to be consistent with this recommendation for more natural characteristics. We understand from Engineering that sodding will be limited to areas near the structure, and we think that this proposal is consistent. 3. There are no substantial grade or slope changes that would produce erosion of the stream bank. In fact, the revegetation program will probably counter the tendency for that north bank erosion caused by the unnatural filling of the river, which has taken place on the Rio Grande property, and which has dramatically changed the course of that river. 4. There will be no building located within the 100 -year floodplain, as designated on the floodplain map. However, the berm proposed to be located to the southeast of the Holy Cross building will intrude within the 100 -year floodplain. Based on the analysis of both the City and County Engineers, we can conclude that this berm will have little effect on flood potential or increasing flood hazard to areas upstream, though this area itself may be subject to flood hazard. The flood hazard to this property has been increased by the fill on the Rio Grande property. As has been recommended in various plans for the improvement of this property, the removal of fill and the res- toration of the natural stream course through this area would only mitigate the flood hazard situation on this site. This is a factor that should be kept in mind when reviewing the Rio Grande Master Plan. The Planning Office recommends a comment of approval be forwarded to the Building Inspector pursuant to stream margin review procedures subject to the following conditions: 1. The paving of the trails linkage be accomplished within a reasonable period of time and that in the interim a surface be maintained that allows pedestrian and bicycle usage. 2. That construction activities be overseen by the Building Inspector throughout the landscaping process. Particular attention should be given to preventing any equipment from disturbing the river bottom and producing stream sedimentation. Erosion could be incurred by careless equipment use on -site and should be avoided throughout the construction phase. 3. Any sodding should be limited to the area immediately adjacent to the Holy Cross building and within the proposed amphitheatre. It is recommended that seeding be utilized for the back side of the berm as well as the rest of the site. A seeding mixture consistent with that recommended in the appendices of the Roaring Fork Greenway plan should be utilized. 4. Consistent with the June 9, 1980 recommendation of the County Engi- neer, there should be no placing of improvements or materials which could float within a direct line from a point above the foot bridge to the Mill Street bridge. This is to prevent their dislocation during a period of any flood, and given the probable tendency of the river to reinstate its original channel. MEMORANDUM TO: Clayton Meyring, Building Inspector FROM: Karen Smith, Planning Director RE: Stream Margin Review for the Aspen Visual Arts Center DATE: June 18, 1980 At their June 17, 1980 meeting, the Aspen Planning and Zoning Commission considered the stream margin review application for a landscaping program at the Aspen Center for the Visual Arts. The program is more fully des- cribed in the application made by Jay Hammond of the City Engineering Department and in the plats attached to that application. The application was reviewed by the County Engineer for impact on the 100 -year flood plain. The Planning and Zoning Commission recommends approval to you, finding the application basically consistent with the recommendations of the Roaring Fork Greenway Plan and consistent with the review criteria under stream margin review. They recommend, however, that approval should be conditioned on the following conditions: 1. That construction activities be overseen by the Building Inspector throughout the landscaping process; particular attention should be given to preventing any equipment from disturbing the river bottom and producing stream sedimentation (erosion could be incurred by careless equipment use on site and should be avoided throughout the construction phase). 2. Any sodding should be limited to the area immediately adjacent to the Holy Cross Building and within the proposed amphitheatre. It is recommended that seeding be utilized for the back side of the berm, as well as the rest of the site. A seeding mixture consis- tent with that recommended in the appendices of the Roaring Fork Greenway Plan should be utilized. 3. Consistent with the June 9, 1980 recommendation of the County Engineer, there should be no placing of improvments or materials within a direct line from a point above the footbridge to the Mill Street bridge if those improvements or materials could float in time of flooding. This would mean that some improvements, such as the sitting log designated, should be either relocated or approved only with tie - downs. If you have any questions about the P & Z recommendation, Clayton, please call me. No. 19 -80 CASELOAD SUMMARY SHEET City of Aspen 1. DATE SUBMITTED: 6/4/80 STAFF: Karen Smith 2. APPLICANT: Aspen Center for the Visual Arts 3. REPRESENTATIVE: Jay Hammond/City Asst. Engineer _ 4. PROJECT NAME: ACVA Stream Margin Review 5. LOCATION: Aspen Visual Arts Center _ 6. TYPE OF APPLICATION: Rezoning Subdivision x Stream Margin P.U.D. Exception 8040 Greenline Special Review Exemption View Plane Growth Management 70:30 Conditional Use HPC Residential Bonus Other 7. REFERRALS: Attorney Sanitation District __School District x Engineering Dept.(C Fire Marshal Rocky Mtn. Nat. Gas _ Housing x Parks State Highway Dept. Water Holy Cross Electric Other City Electric Mountain Bell 8. REVIEW REQUIREMENTS: i'CCblwrts 16r._ -kn Pta a CL1Y\1%5S11f✓\ AI.e. "BOA I kot e P1.24/4114s ' . a 9. DISPOSITION: / P & Z Approved Denied _ Date L1/�0 T r 1 P -I ) t� { L J efiak11614; 614 ilk ttlf ghgl -- J Council Approved Denied Date 10. ROUTING: Attorney y Building Engineering Other i1 � i 1 1 I • / I , , 1 1, 1 i t , � � +, / ;; \��� pitkin county east main street aspen, Colorado 8'1601 M E M O R A N D U M TO: Karen Smith, Planning Office FROM: Patrick Dobie, County Engineer DATE: June 9, 1980 RE: Stream Margin Review - Visual Arts Center It appears the proposed landscaping and berm construction as proposed will have little if any adverse affect should a 100 year frequency flood occur. Although the berm could possibly create a backup, the stream gradient is sufficiently steep to handle this slight constriction at this specific location. On a larger scale, however, the Mill Street Bridge would act as the main control inundating the site and backing water above the location of the berm and thus negating its affect altogether. In other words, "no problem!" Originally, the Roaring Fork flowed on a course which divided this area and there existed an island where the large cottonwoods now stand. Should a major flood occur, the River may seek to reinstate its original channel. Therefore, I would discourage the placing of any improvements or materials which could float within a direct line from a point above the foot bridge to the Mill Street Bridge. CITY - PEN 130 s ;, . trees aspen ` - 81611 Aspen Planning and Zoning Commission 130 South Galena Street Aspen, Colorado 81611 Date: May 29, 1980 Re: Stream Margin Application for the Aspen Center for the Visual Arts Dear Sirs; This application is for stream margin approval of the proposed landscape work to be done on the old Holy Cross property, currently known as the Aspen Center for the Visual Arts. The bulk of the work involves importing of topsoil, placement of sod and grass seed, and planting of various trees and shrubs. While most of this work will take place within the 100 year flood zone as designated by the Army Corps of Engineers, none of it in- volves significant regrading nor does it adversely affect the flood zone, which covers most of the site. A copy of Henry Pederson's landscape plan will be available at the meeting for your consideration. The most significant landscape feature with which this appli- cation is concerned involves the proposed construction of a berm at the southeast end of the building that would serve as a grass - covered amphitheater for outdoor presentations and performances. The berm is to be constructed of material already located adjacent to the river that includes some native fill resulting from the Arts Center construction as well as some old spoil material that was in place when the property belonged to Holy Cross. It is our inten- tion to create a semi - circular bermed area at the southeast end of the building based on the existing spoil material and covered with topsoil and sod or grass from seed. The berm borders the 100 year flood zone and would, in fact, create a restriction in the zone. I would submit, however, that the proposed berm is intended to blend into the bank on the upstream side and provide a "step" effect in the flood zone. In other words, this berm is to be immediately down- stream of a greater restriction in the stream bed and would there- fore have no effect on the flood zone upstream of the site. The berm would serve to protect the site and would be an asset to the river greenway by creating a pleasant seating area outside of the Arts Center. I would also suggest that most of the material to be utilized in the berm is already in place at a location closer to the river and that construction of the berm may actually serve to pull this material away from the river and reduce the restriction on the flood zone. In short, we are attempting to reshape and smooth existing material on the Visual Arts Center site to create a more pleasant and landscaped environment. The bulk of this work takes Page 2 Re: Stream Margin Application for the Aspen Center for the Visual Arts place within the flood zone and as such requires your approval. The Center, with the voluntary cooperation of its members and a landscape architect, hopes to turn the Holy Cross property into a quality park environment in keeping with the Roaring Fork Greenway Plan and requests your approval of this landscape design. y trul yours, / J y W. Hammond ssistant City Engineer JH:ln L e. Y MEMORANDUM TO: Pat Dobie, County Attorney Jim Holland, Parks Director FROM: Karen Smith, Planning Director RE: Stream Margin Review - Aspen Center for the Visual Arts DATE: June 5, 1980 The attached is a request for stream margin review for proposed landscape work at the Aspen Center for the Visual Arts. This application is scheduled to come before the Aspen Planning and Zoning Commission on June 17, 1980; therefore, may I please have your written comments concerning this appli- cation by June 13? Thank you for responding on such short notice.