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HomeMy WebLinkAboutLand Use Case.605 S Alps Rd.13A-87l n ojes 6U4U , 97. VV L.,f-J /~////7/,1,+4 3,· 7 1- qu .44 609 9 Al ~ 6 148 6-reen jineSFecial Reviw /3A-81 f Brp/tuil 01 1) n ~ ITR# 0 L.... J MEMORANDUM TO: Aspen Planning and Zoning Commission FROM: Glenn Horn, Assistant Planning Director RE: Moses 8040 Greenline Review DATE: June 16, 1987 BACKGROUND INFORMATION Applicant: Gaard Moses Applicant's Representative: Gideon Kaufman Location: South of the Aspen Alps just to the east of Little Nell ski slope (see attachment 1) Zoning: R-15 PUD Size: 1 acre (43,560 square feet) APPLICANT'S REQUEST The applicant is requesting 8040 Greenline Review approval in order to reconstruct a single-family house on the subject site. PREVIOUS P&Z REVIEWS On January 28, 1987 the P&Z reviewed a request from this appl- icant for rezoning from C (Conservation) to R-15 PUD and a subdivision exception for the purposes of creating two lots. The P&Z recommended approval of the applicant's request and the City Council subsequently granted approval to the applicant. At the City Council meeting the applicant indicated that it was his intention to return to the P&Z in the Spring to go through a 8040 Greenline review to reconstruct one of the dwelling units on the site. REFERRAL COMMENTS 1. Engineering Department: Due to an unusually substantial work load the Engineering Department was not able to provide the Planning Office with written comments concerning this application. However, Jay Hammond has reviewed a geological report prepared by Chen & Associates regarding the Moses property and met with the applicant (see attachment 1, Chen report). Based upon Jay's review of the report and discussions with the applicant he has made the following two recommenda- tions: a) Mitigation measures such as deflection walls and berms should be constructed on the east side of the proposed dwelling to protect the residence from the possibility of a mud flow. b) Additional studies of the potential for a large mud flow should be undertaken to the satisfaction of the City Engineer prior to a date established by the P&Z. PLANNING OFFICE COMMENTS Section 24-6.2 of the Municipal Code establishes specific review criteria for 8040 Greenline review. This section lists the criteria and addresses each of them individually. 1. Criteria - Whether there exists sufficient water pressure and other utilities to service the intended development. Response - The development is presently served by the local sanitation district and service is adequate, the development presently utilizes a well, however, as part of the subdivision exception process approved this winter, the applicant agreed to connect to the City of Aspen water system. 2. Criteria - The existence of adequate roads to insure fire protection, snow removal and road maintenance. Response - During review of the subdivision exception it was established that roads serving the site are adequate. 3. Criteria - The suitability of the site for development considering the slope, ground instability and possi- bility of mud flow, rock falls and avalanche danger. Response - About one month ago there was a minor mud flow on the subject property. Although the mud flow did not disturb the proposed building site it did come close enough to cause US to look closely at the potential for a larger mud flow. The City engineer has commented above concerning the geologic report concern- ing the mud flow which was filed by the applicant. The Planning Office supports the view of the City Engineer. 4. Criteria - The effects of the development on the natural watershed, runoff, drainage, soil erosion and 2 consequent effects on water pollution. Response - The site plan for the proposed development calls for the new residence to approximately match the existing building footprint. Therefore, it is not anticipated that there will be any adverse effects on the surrounding environmental features in the area. 5. Criteria - The possible effects on air quality in the area and city wide. Response - There will be no adverse effects on local air quality resulting form this development. 6. Criteria - The design and location of any proposed structures, roads driveways or trails and their compatibility with the terrain. Response - The location of the structure will not be altered significantly. Due to the isolated location of the building site, the residence will not be highly visible from off the site. Roads serving the site will not be relocated. 7. Criteria - Whether proposed grading will result in the least disturbance to the terrain,, vegetation and natural features. Response - There will be very little disturbance to the terrain on the site, with the exception of the con- struction of a berm on the east side of the property which is intended to protect the property from a potential mud flow. 8. Criteria - The placement and clustering of structures SO as to minimize roads, cutting and grading and increase the open space and preserve the mountain as a scenic resource. Response - In our opinion, the existing house is located on the ideal location on the subject site. The building site is relatively flat and out of site from neighboring properties. 9. Criteria - The reduction of building height and bulk to maintain the open character of the mountain. Response - As mentioned already due to the excellent citing of the house, the design and size of the structure is not of great significance to this review. The house is restricted to 3,800 square feet in size. 3 RECOMMENDATION It is our opinion that the most significant issue associated with this application is the potential for another mud flow affecting the site. Based upon a site visit made by the Planning Office and City Engineer, it does not appear likely that there will be a mud flow which will affect the proposed residence. However, the Chen report leads us to believe that more definitive information should be provided before the final building plans are approved. Therefore, the Planning Office recommends approval subject to the following conditions. 1) All representations made by the applicant will be adhered to. 2) Mitigation measures such as deflection walls and berms should be constructed on the east side of the proposed dwelling to protect the residence from the possibility of a mud flow. 3) Additional studies of the potential for a large mud flow should be undertaken to the satisfaction of the City Engineer prior to the issuance of a building permit for the proposed reconstruction of the dwelling unit. Moses8040/gh 4 re* Chen a associates 5080 Road 154 Casper Glenwood Springs, CO 81601 Colorado Springs I O ll Consulting Geotechnical Engineers 303/945-7458 Denver Fort Collins U- Rock Springs Salt Lake City San Antonio May 27, 1987 Subject: Potential Geologic Hazards Reconnaissance for the Gaard Moses Property, Aspen, Colorado. Job No. 4 194 87 Mr. Gaard Moses P.O. Box 21 Aspen, Colorado 81612 Dear Mr. Moses: This letter summarizes the findings of a geologic hazards reconnaissance made for the Gaard Moses property. The purpose of the reconnaissance was to observe the geologic conditions in the vicinity of the site and to identify conditions which could have an adverse impact on the construction of a new residence at the location of the existing house. The investigation consisted of a field reconnaissance and review of published geologic literature. Site Conditions: The Moses property consists of an irregular-shaped parcel which covers about 0.5 acres. The property is located at 800 South Alps Road, Aspen, Colorado. The property is on the lower slopes of Aspen Mountain. Terrain at the site is very steep with slopes of about 40% to 50%. A two-story wood frame house occupies the lower northern part of the property. A single-story wood frame house occupies the lot to the west and the Aspen Alps condominiums are located further west. The hillside in the vicinity of the proposed building site is generally forested with dense stands of aspens and conifers. The channel of Spar Gulch parallels the eastern property line and is located about 25 feet east of the existing house. Proposed Construction: The existing house Will be razed and a new residence constructed at the same site. The new residence will be a one- to two-story wood frame structure without a basement. Specific structure and grading plans for the new home have not been developed. It is our understanding that the new construction will not require substantial site grading. Mr. Gaard Moses May 27, 1987 Page.2 Evaluation: Based on the findings of this investigation there are several conditions of a geologic nature which should be considered. Building Foundation: We do not anticipate difficult foundation conditions. After the existing house is razed a site specific subsurface investigation should be conducted to evaluate ground-water conditions, bearing capacity and potential volume change characteristics of the foundation soils. Slope Instability: The slopes in the immediate vicinity of-· po *sm.i·- the existing house and the proposed new residence appear to be 'DAP„ ~112€E S stable under present environmental conditions; however, grading 1 }0 AQ.64 of the steep slopes could result in local instability, particularly if ground-water seepage is encountered. A local landslide occurred this spring upslope of the building site in an area of active springs. The landslide is located near the southern part of the property about 180 feet to the south of the existing house. Debris from the landslide were mixed with spring water discharge and traveled as a small debris flow in the Spar Gulch channel. Some of the debris were deposited near the existing house. Some debris were transported further downslope and were deposited on the Chance property. As with all construction on steep mountain slopes there is some risk of slope failure. Since substantial grading is not anticipated for the new construction the impact of the construction on slope instability is considered to be low. Preliminary grading plans should be reviewed by a geotechnical engineer prior to final design and construction at the site. Slope instability at the site could also be related to grading on adjacent properties. Grading on adjacent properties should be evaluated prior to construction. Debris Flow And Flooding: The localized landslide which occurred upslope of the proposed building site this spring resulted in a small debris flow. The bulk of the debris were confined to the channel of Spar Gulch; however, some debris were deposited on the property. These debris did not reach the existing house. In our opinion there is a potential for larger debris flow along Spar Gulch. Additional studies should be undertaken to - lue WAVU 4 determine the probable debris flow and water flood impacts. The :w:rs:P~ water flood and debris flow evaluations will require the services of a surface water hydrologist who is familiar with the local TUE €Aer 564 06 #.AS drainage conditions and the city's master drainage plan. 2Alfee '3 ' / Mitigation measures such as deflection walls and berms may be Chen &Associates Mr. Gaard Moses May 27, 1987 Page .3 4 required to protect the new residence. Any flood or debris flow mitigation measures for this site should be coordinated with other property owners along the Spar Gulch drainage way. The mitigation measures should be compatible with the city's master drainage plan. We are available to assist the surface water hydrologist in evaluating the debris flow aspects of the drainage evaluation. Abandoned Mines: Review of the extent of mining map by Bryant, 1972, and general mining maps of the Aspen district in our files show that the site may be underlain by abandoned mine workings. If uncaved stopes or mine portal are present near the building site then there may be a potential for damaging mine subsidence. This potential should be assessed by further studies. We recommended the additional studies consist of an inventory of available mine maps showing the extent of mining in the area. The location of the site with respect to the mine workings I should be determined using surveys from identifiable surface mine i features such as the Lower Durant Tunnel portal. The locations of the workings indicated by these reviews can then be used to assess the subsidence potential. Limitations: This report has been prepared in accordance with generally accepted geotechnical engineering practices in this area for use by the client for preliminary site evaluations. As indicated, several conditions were present which warrant further investiga- tion prior to design and construction. If there are any questions concerning this report or if we may be of further service, please let us know. Sincerely, CHEN & ASSOCIATES, INC. 042 4 #*? 1 5222 , J*1 d&04£ A , 227 04 &, re- ..24 By ./.0.4 RalRA G. Mock, J>:.7/ONAL PI**P Engineering Geologist 492065.8820& RGM/rrb Rev. By: S.L.P. Chen & Associates References Bryant, Bruce, 1972, Mine Locations and Metal Production, Aspen, Colorado: U.S. Geol. Survey Map I-735-D. Chen &Associates I r- - \227 ilt-- 4 7-- --41 -17>~- »\-»«2-1.- A achind'4114 \'F.~*)~f \\ I..Niz\.4>ll . · 141 1 .J»\ XX. \ 7 1 . --<1492~/4 i 1 ..\.\ ... \ 1, I\ 4 111 X 1, - v Iii li 4 a lili lw-1 --- '..< 1 i j 1 ' i l- 41]. 1 0 1\\Id 1 . 0/ - € 1 1 . 1\ r 113 . \4 t ,1 2J ~ \.114 A,N-)60 /\LP>lt \ l,\4290 1-Tr VY C.1 \ /./,-/3 th<%9\ 43\7VUA , 0 64« 44 . ---- i i *8069.1 · 1 j u~ f 1 849~ » ·6 \'>·2 5 / N .... . 1\.\\ 0-1-f\*42~~~~3)1~- 0.24 t. \ 4\Nt \ 6. I -#· A\€r--72. \ 41 \11 \ j 1 ) 2 DITTE,0253<tpe'l, C ((Con-» . R \6·01 5'PAC- 11/.*- -< X '.2. ·4: i:.1 411 iii ' f (1929-7 ) ~<huzzE \ 8040-- 8050--- 31~%·,2- ~- i : j , t\,, it \\~ ijct ~f~~4-141 - <1-~ 806Q-- I- · ~ ~~ 11 ~ ) .·~5;~1 ~ At\·Acohmon~7-- \ 1 <'12 -8100--EZZ7 - £ .11/ ----- -81,0.-=====ZE== --- I 11 0120-- ---ZE=-81---ZE=- --- E-- /-2723--2---*-----~--~,6,)-2 ---- -EE---60 ZZ=DZ==-2225~292 1 M \11\1 . \r -111111 LAWOFFICES APR)01987~~ GIDEON 1. KAUFMAN APROFESSIONALCORPORATION BOX 10001 315 EAST HYMAN AVENUE. SUITE 305 ASPEN, COLORADO 81611 GIDEON 1. KAUFMAN TELEPHONE AREACODE 303 RICHARDS. LUHMAN 925-8166 April 23, 1987 Mr. Glen Horn, Associate Planning Director Aspen/Pitkin County Planning Office 130 S. Galena Street Aspen, Colorado 81611 Re: 8040 Greenline Review/Lot 1, Moses Lot Split Dear Glen: Please consider this letter an application for 8040 Greenline review pursuant to Section 24-6.2 of the Zoning Code of the City of Aspen. The application is submitted on behalf of Gaard Moses who seeks to comply with the commitments he made in the recent rezoning and subdivision of his property. This application deals with Lot 1, Gaard's home, and its conversion to single-family residential use with a floor area not to exceed 3,800 square feet. The plans for modification of the existing structure are being prepared by Bill Poss within the parameters of the building footprint on the Conceptual Design Study submitted herewith. We believe that, because this conversion only slightly modifies the existing structure, it fully complies with the intent of Section 24-6.2 in minimizing additional impacts to this transition area. In fact, the conversion of this structure to single-family will, in the long run, not merely minimize impacts but reduce them through the less intensive resulting use. The criteria set forth for Greenline review are all met in this particular situation: 1. The existence of sufficient water pressure is guaranteed by the applicant's agreement to implement the water connection plan shown on the final subdivision plat as contained in the Subdivision Exception Statement recorded in connection with the plat. This plan involves running approximately 400 feet of pipe to connect with the City's high pressure water main located in the nearby ski slope. 2. Submitted herewith is a letter dated April 2, 1987 from Wayne L. Vandemark, Fire Marshall, indicating sufficient fire access to the Moses' residence. Snow removal and maintenance of the Aspen Alps road is adequately provided by private contract. Mr. Glen Horn April 23, 1987 Page 2 3. The structure which we have proposed to modify has been located on this former railroad roadbed for approximately thirty years without problems from ground instability, mud or rock slides, and avalanches. The proposed modifications are quite minor and suggest no impacts. 4. This project's modest modifications to the existing structure will have no effects on the natural watershed runoff, drainage, soil erosion and consequent water pollution. 5. The possible effects on air quality in the area and City wide will be only those resulting from construction during the remodeling and should actually improve in the long run due to the reduction in use of this structure. 6. The design location of the proposed structure, roads, driveways or trails will not be significantly amended. The upgrade of the structure will involve the use of materials compatible to the surroundings and result in a much more esthetically pleasing structure. 7. Other than the introduction of some additional foundation walls very close to the structure there will be no disturbance to the terrain, vegetation or any natural land features. This is more fully addressed in Bill Poss' letter submitted herewith. 8. As you have observed, the existing residential structure is located in the ideal building site from the public's perspective in that the site is a pre-existing railroad roadbed and quite flat. For this reason, the slight modifications of the structure's footprint disclosed by the site plan being submitted herewith minimize the impact on this already developed site. There will be no impact from roads which are already in existence and no further cutting or grading to disturb the existing natural terrain. 9. The Conceptual Design Study which is submitted herewith discloses the extent by which the roof plan of this structure is to be modified. The existing structure is constructed on a pre-existing railroad roadbed which is below the natural grade of the property and which enhances and minimizes any impact of this modification on the well forested existing natural slope of the mountain. In fact, the actual site is located over 70 feet below the Little Nell ski slope to the west and for years (until the Gondola was constructed) few people in the community even realized that the property was developed. While the property is now visible from the gondola that overhead viewplane will remain relatively unaffected by the proposed modifications and, if anything, improved esthetically by the upgrading of the structure which the applicant seeks permission to accomplish. Mr. Glen Horn April 23, 1987 Page 3 Enclosed are the items mentioned above together with our application fee, a pre-addressed envelope to be used to notify the Aspen Alps of the Greenline review date together with the fees for processing this application. While I believe you will find the enclosed in order I would appreciate your contacting me to discuss any concerns you may have with them. Otherwise, I look forward to having this placed on the next available agenda. Naturally, I appreciate and wish to thank both you, the Planning Office and the Planning and Zoning Commission for their consideration and help in this matter. Very truly yours, LAW OFFICES OF GIDEON I. KAUFMAN, a Professional Corporation By % r--- Gidd¢n Kaufman GK:bsr Enclosures ; and associates 605 EAST MAIN STREET ASPEN, COLORADO 81611 TEL (303) 925-4755 April 28, 1987 Messrs. bideon Kaufman and Richard Luhman 315 East Hyman Avenue Aspen, Colorado 81611 Gentlemen: Attached is a copy of the conceptual design study for the Moses remodei. Briefly, our concept is to remove the upper srory of the existing structure, replace it with a new design for the - upper level, and create a new roof structure. The new structure will be within the existing clearing, approximatelv over the existing structure, which will minimize the impact to existing vegetation and grading. [he program calls for expanding the structure to the south at the second level over an existing graded embankment, and to the north with decks to cover some existing parking. I will keep you informed as the designs develop. If you have any questions, please don't hesitate to call. Sincerely, 44/ 0 1 1 0, 7<1 i L. - / UP:dem Enclosure '1 4 P i +047 37/ r April 2, 1987 To Whom It May Concern: The Aspen Fire Department does have access to the G. Moses residence on Aspen Alps road. Wafhe L. Vandemark Fire Marshal C U ASPEN/PITKIN PLANNING OFFICE 130 S. Galena Street Aspen, CO 81611 (303) 925-2020 7 ' 4 2 6 Date: fl.t (· t.1 . , ~ i i '( 4 --f f.. \ / ' d -lq N A U) /4N i. t , 4 4 8 L l._ - -1 ,- -42: il'*. ' 1,,' j , 3 14 1 L j K ..p Y l Ul t'·~. ..../ RE: 7/ u i 1 9-(/1 4 i j (i / (tri 14 0.4€.t-,Li..-3 Dear 0 L rl./ o li-1, _ : This is to inform you that the Planning Office has completed its preliminary review of/-the captioned application. We have determined that your application 43# NOT compl ete. Additional items required include: Disclosure of Ownership (one copy only needed) , Adjacent Property Owners List/Envelopes/Postage (one copy) Additional copies of entire application Authorization by owner for representative to submit appl ica- tion Response to list of items (attached/below) demonstrating compliance with the applicable policies and regulations of the Code, or other specific materials / A cheak in the amount of $ A. Yolir applicatio# £s complete and we haye scheduled it for r ev i ew by th e x f ~»'92- on (dil 10- 46 . We will call you if we nedd any additional inforniktion prior to that date. Several days prior to your hearihg, we will call and make available a copy of the memorandum. Please note that it IS NOT your responsibility to post your pro perty with a sign, which we can provide you for a $3.00 fee. B. Your application is incompl ete, we have not scheduled it review at this time. When we receive the materials we have requested, we will place you on the next available agenda. If you have any questions, please call ~~-tff k.'2-*~ the planner assigned to your case. Sincerely, ASPEN/~TKI N PLANNING OFFICE 4 f Cult.r li - J ,™e .A . *. . I I . A - . - 0 2 7 .... ... 0 0 0 . 1- 21/4 0 0 1 I#.*-*HZ- 1 W - -1 , i kij i· j. ! li Oeflec. 0*v,gr / Ps·Jr ~ i, i t t 4 - · .4 · I 11 W ¢1#9- / 3LME CM¥- 402' · i.?f..f-*f: / .f' i . -17 8 --,/3 .....- r -0 .: t \ ..e /31-_ 4'. 1 76 7.- t. - ... 1 -392.-7 ./ -- 1 : , 1.-74.- . 5/2 / , 1 . 4.-/ 0 »ly I -ha. \ I \ I I --24/7 - // -- Issue: , . li.2- ~~~a..... -2 . . '7.- --Wf~ ' 4 24· 69 - Jok»PRJAL *TUDW 4,-6,51- &40 €SVIEW 4)15>MISSIDI '' , ~:. 5 - /3 -1 4 f- ./ F f ..1 ~ E><192 N 0 -EME-5 LI NE- - j g,ver- 1~94::4 k \ :25 4 .9 . I ./ L . .4.r. rk .....11 \9 1/ / \ A .i; 1 1 i ' f.1 1 : A . ..% 4 "\,pe, ' . , F , 7, 4, u. ' 0@-9.4 \ h A. - SELECTING FABRICATION PROCESSES AND TECHNIQUES OF 02,34//0 R 4'-, 9 5 jA.I*7 U¥-9. t :* 4 4 iFA Zlzib:7992 'EXISTINg, . U /4,. rf<kf j 1 /7 1 ' f. *001 .98 f...' f :; E*4VE:- , 1, 1 9 , ; I . ..,«», I . . / 2 I i K.15-, I 4.- 4 - **7 rs,X , i.. t .1 ill r 4.' I.·*0' I .· 9 . N / 1 /1,4 0 . / 1 . N ~' r .,r THE PURPOSE OF THIS DRAWING IS ONLY TO GRAPHICALLY it,14'll....4·11 i ?; i j : j i i f l.//> ~~ 1. 4¢ *77 \- ' , DEPICT THEGENERAL NATURE OFTHEWO~ ™ECONmAC r - . /4-Iff TORI IS RESPONSIBLE FOR CONFIRMING DNENSIONS, AND . VARIATIONS FROM THE DIMENSIONS AND CONDITIONS i / 71 1- N CONSTAUCTION THE ARCHITECT SHALL 8E NOTIFIED OF ANY 0 ·2Zor. 4 47: 1.\ /. SHOWN BY ™IS DRAWING 3 - 4 »7 A / CONCEPTUAL DESIGN 7 *" r . 4--7- 1 I .f STUDY 1 , A 8040 GREENLINE REVIEW 0- . 1 --- 9 --- * F-1 --#- Scale: 1 '- 10' 24131T CONAL- 19·8%4 437 ~ LINES (r ExIST(Ne' dIN nAT e, re[*i, .2 STCJ¢©f spwclu,2.2.- %+0- . % 4-/ --r"- -#i* , / © FIP- wil i IAM .Ir»AN Pnqq