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HomeMy WebLinkAbout20050914satrangTO: THRU: FROM: RE: MEMORANDUM Board of County Commissioners Regular Meeting- September 14, 2005 Cindy Hoube ,n~C~mmunity Development Director Suzanne Wolff, Senior Planner* ZTS Construction Incorporated Request for Constrained Lot TDRs REQUEST: The Applicant submitted a request to the Community Development Depamnent pursuant to Section 3-310-054 (adopted pursuant to Ordinance No. 052-2004) to make a determinatioa whether the lots are "undevelopable or severely constrained" in order to obtain TDRs in exchange for preservation of the lots. The Community Development Department has determined that the lots are constrained, as described below, and are eligible for TDRs. Pursuant to Section 3-310-053.2, the BOCC "shall determine that principles of equitable mitigation favor relief in the form of issuance of one or more TDRs.' APPLICANTS: ZTS Construction Incorporated, Zack Satrang REPRESENTATIVE: Glenn Horn LOCATION: Lots 15, 16 & 17, Crystal River Park Subdivision Second Addition ZONING/LOT AREA: The lots contain 2.179, 1.397 and 0.752 acres, respectively, and are nonconforming size lots in the RS-30 zone district. BACKGROUNI}/DESCRIPTION: The lots are located along the upper boundary of Crystal River Park Subdivision directly below the steep sandstone cliffs to the north (photo attached). The BOCC approved the Crystal River Park Subdivision Composite Plat (including First and Second Additions thereto) in July of 1966. The BOCC then approved an amendment to the Plat in 2002, which vacated High Drive and established an access easement to Lots 15-17. The Land Use Code states, "Common ownership of contiguous substandard size lots or parcels shall cumulate with the exception that lots in subdivisions approved and signed by the Board of County Commissioners shall not cumulate regardless of their size." Therefore, each of Lots 15-17 is separately developable. PROCESS: Staff is to review the request and make a determination whether the proposed preservation sites are undevelopable or severely constrained under the Pitkin County Land Use Code. If there is a determination that that the property is not developable, The Board shall, at a public meeting, make a determination as to whether one or more constrained lot TDRs will be granted, subject to the principles of equitable mitigation. DETERMINATION OF CONSTRAINED LOT: The Community Development Department finds that the lots are "undevelopable or severely constrained" pursuant to the Land Use Code, based on the following: Slopes: Lots 15, 16 and 17 are primarily comprised of slopes in excess of 30% (97%, 99% and 76% respectively), with the majority of Lots 15 and 16 comprised of slopes in excess of 45% (90% and 75%). The Land Use Code prohibits development on slopes in excess of 45%, and in most cases over 30%. A~,alanche: Art Mears evaluated the avalanche hazard and determined that two avalanche paths affect the lots: one that primarily impacts Lot 15 and one that affects Lot 17. On Lot 15, the red zone continues all of the way through the lot. On Lot 17, the upper portion of the lot is within the rod zone, and most of the remainder of the lot is within the blue zone. The driveway to Lots 15 and 16 would cross the blue zone. The Code prohibits development within a red or high avalanche hazard zone; the Code permits development within a blue or moderate avalanche hazard zone only if the entire property is affected and if the bazard can be adequately mitigated. Debris Flow andRocl~all: All tbree sites are on alluvial fans and are within the potential rockfall runout zone. HP Geotech states, "A major debris flow event could result in damage to buildings on tbe three lots and present a safety risk to the occupants of those buildings." "A high velocity rockfall similar to past rockfalls on Lot 15, Lot 16 or Lot 17 would result in severe damage to buildings and other facilities and will present a life safety risk to the occupants of the buildings. During our field roconnaissance of the property, several large rockfall blocks measuring 25 to 35 feet in size with estimated weights of 5,400 to 14,800 tons were observed on Lots 16 and 17." The Code prohibits development within rockfall hazard areas, and permits development on alluvial fans, subject to mitigation. Wildfire: Eric Petterson rated the wildfire hazard on all three lots as severe. The Code permits development within severe wildfire hazard areas. Staff bas determined that, in accordance with Section 3-310-054.1, the lots are not developable pursuant to the Pitkin County Land Use Code. The Board sball make a determination as to whether one or more constrained lot TDRs will be granted. STAFF RECOMMENDATION: The principal of equitable mitigation, which governs the action of the Board, does not require an analysis based upon value of the land relative to the value of TDR's, consideration of whether or not to grant TDR's and how many to grant are based on fairness reflective of the overall situation of the property and its history. Staff recommends that one TDR be issued for each lot. 2 Cliffs behind Lots 15, 16 and 17, Crystal River Park Subdivision Second Addition RESOLUTION OF THE BOARD OF COUNTY COMMISSIONERS OF PITKIN COUNTY, COLORADO, GRANTING A CONSTRAINED LOT TDR FOR EACH OF LOTS 15, 16 AND 17 OF CRYSTAL RIVER PARK SUBDIVISION TO ZTS CONSTRUCTION INCORPORATED Resolution No. -2005 RECITALS ZTS Construction Incorporated, Applicant; has applied to the Pitkin County Department of Community Development for a constrained lot determination and to the Pitkin County Board of County Commissioners (BOCC) to determine whether one or more constrained lot Transferable Development Rights (TDRs) should be granted. 2. The lots for which the determination is requested are described as Lots 15, 16 and 17, Crystal River Park Subdivision Second Addition. 3. The'lots contain 2.179, 1.397 and 0.752 acres, respectively, and are nonconforming size lots in the RS- 30 zone district. The BOCC approved the Crystal River Park Subdivision Composite Plat (including First and Secood Additions thereto) in July of 1966. The BOCC then approved an amendment to the Plat in 2002, which vacated High Drive and established an access easement to Lots 15-17. The Land Use Code states, "Common ownership of contiguous substandard size lots or parcels shall cumulate with the exception that lots in subdivisions approved and signed by the Board of County Commissioners shall not cumulate regardless of their size." Therefore, each of Lots 15-17 is separately developable. 5. The Community Development Department bas determined that the lots are "undevelopable or severely constrained" pursuant to the Land Use Code, based on the following: A. Lots 15, 16 and 17 are primarily comprised of slopes in excess of 30% (97%, 99% and 76% respectively), with the majority of Lots 15 and 16 comprised of slopes in excess of 45% (90% and 75%). B. The west side of Lol 15 is within the red avalanche zone. A portion of Lot 17 is within the red avalanche hazard zone and most of the remainder of the lot is within the blue avalanche hazard zone. The driveway to Lots 15 and 16 would cross the blue avalanche hazard zone. C. All three lots are subject to debris flow, severe rockfall, slope instability and severe wildife hazard. The BOCC reviewed the request for a determination as to whether one or more constrained lot TDRs will be granted at a public meeting on September 14, 2005, at which time evidence and testimony were presented with respect to this application. 7.. The BOCC determined that one constrained site TDR shall be granted to each of Lots 15, 16 and 17. NOW, THEREFORE, BE IT RESOLVED, by the Board of County Commissioners of Pitkin County, Colorado, that due to the fact that tbe Community Development Department has determined that Lots 15, 16 mid 17, Crystal River Park Subdivision Second Addition are undevelopable or severely constrained under the Pitkin County Land Use Code, one constrained site TDR shall be granted to the Applicant or successors in interest for each of Lots 15, 16 and 17. ATTEST: Jeanette Jones Deputy Clerk and Recorder Resolution No. -2005 Page 2 APPROVED AND ADOPTED ON THE 14th DAY OF SEPTEMBER, 2005 BOARD OF COUNTY COMMISSIONERS OF PITKIN COUNTY, COLORADO By Patti Kay-Clapper, Chair Date APPROVED AS TO FORM: John Ely County Attorney APPROVED AS TO CONTENT: Cir~y~Houben Community Development Director PID #272929202004 Case P157-05 Davis Hornm c. PLANNING & REAL ESTATE CONSULTING June 29, 2005 Lance Clarke AICP Aspen Pitkin County Community Development 130 South Galena Street Aspen, CO. 81611 RE: Crystal River Park Subdivision Lots 15, 16 and 17: Ordinance #52-2004 Constrained Site Transferable Development Rights Dear Lance: Davis Horn Incorporated represents ZTS Construction Incorporated, owner of Lots 15, 16 and 17 Crystal Park Subdivision Second Addition (hereinafter applicant). ZTS Construction Incorporated is owned by Zack Satrang of Windsor, Colorado. The applicant is seeking an administrative decision by the Pitkin County Community Development Department that each of the three separate subject properties is Uundevelopable or is severely restricted" pursuant to Ordinance #52 of 2004 and the Pitkin County Land Use Code. If and when such an administrative decision is made, the Board of County Commissioners may employ the principles of equitable mitigation to determine whether or not to allow a development right to be severed and transferred from each of the properties and how many development rights should be recognized for each property. Of particular importance in the Pitkin County Community Development Department's administrative decision is the review standards concerning environmental preservation and avoidance of hazardous areas. This letter address the issues under the headings: * History of the Subject Lots * 1041 Environmental Hazards * Findings Pursuant to Ordinance #52-2004 * Summary. HISTORY OF THE SUBJECT LOTS Each of the subject lots is separately developable. The Crystal River Park Subdivision Second Addition which originally created Lots 15, 16 and 17 was approved by the Board of County Commissioners on July 18, 1966. Attachment 1 is a copy of the ALICE DAVIS, AICP ~ GLENN HORN, AICP 2]5 SOUTH MONARCH ST. · SUITE ]04 · ASPEN, COLORADO 8]6]] · 970/925-6587 · FAX: 970/925-5]80 Lance Clarke AICP June 29, 2005 Page 2 Plat which is recorded at Plat Book 3 Page 103. In 2002, the Amended Plat of Lots 3, 15, 16, 17, 18, 19 and 20 Crystal River Park Subdivision was approved and recorded at Plat Book 61, Page 14 (see Attachment 2). The amended Plat vacated the public road, High Drive (formerly know as Aspen Drive and often referred to as the last section of Ruby Mountain Drive), the access road to the three subject properties. However, the 25 foot High Drive road became a driveway and utility easement serving the lots. The other lots referred to on the Amended Plat, Lots 3, 18, 19 and 20 were only minimally affected as their access via Ruby Mountain Drive remained essentially the same. The driveway easement was sufficient for meeting the access needs of the three subject parcels, Lots 15, 16 and 17. During the review process in 2002, it was clarified and confirmed that the three lots were individual, separately developable lots. Attachment 3 is a copy of Ordinance No. 8 of 2002 which granted approval for the Amended Plat. The applicant contracted to acquire the subject lots in October of 2002 from CRV Properties, LLC and closed on the lots in December of 2002. On December 1, 1975, the Pitkin County Board of County Commissioners adopted Resolution 75-97 which enacted 1041 Hazard Review Regulations for geologic hazard areas, floodplains, wildfire, and wildlife habitat areas. Until July of 2002, Pitkin County did not require lots in Board of County Commissioner approved subdivision to comply with the 1041 Environmental Hazard Review standards. In July of 2002, for the first time, the Board of County Commissioners began to require lots in Board approved subdivisions which never went through a 1041 Environmental Hazard Review to go through the 1041 hazard review process and comply with County Land Use Code standards. The applicant, the seller and his real estate broker were not aware of this change in County land use policy when the lots were sold which is understandable because there was not a public notice or public hearing. The applicant was informed by the County staff of the 1041 Environmental Hazard Review requirement at a October 2, 2003 pre-application meeting (see Attachment 4, Pre-application Conference Summary Sheet). Initially, the applicant was proposing to develop a vacation home on Lot 17. In the fall of 2003 and in the winter of 2004 the applicant hired experts to study all three lots. However, due to the many constraints impacting the property including avalanche, rockfall, steep and unstable slope hazards, development plans were postponed because the applicant believed the lots might not Lance Clarke AICP June 29, 2005 Page 3 be developable. Until the Board approved Ordinance 052-2004 in December of 2004, the applicant was not sure what to do with the three lots. Due to the many constraints on each lot, as an alternative to the development of three single family homes, the owners are seeking a determination that the lots are undevelopable or severely constrained, so that TDRs can be separated and transferred off the lots. 1041 ENVIRONMENTAL HAZARDS Lots 15, 16 and 17 are zoned RS-30. Ail three lots are located on a series of coalescing alluvial fans down slope of prominent sandstone cliffs. Vegetation consists of native grasses and weeds with scrub oak, aspen and scattered conifer trees. Potential geological hazards that could affect all three lots are debris flow, rockfall, potentially unstable slopes and snow avalanche. There are large rockfall blocks or boulders, some up to 35 feet in size on all three lots. This section of the letter summarizes 1041 Environmental Hazards impacting the subject lots under the headings: * Steep Slopes; * Debris Flow, Rockfall and Potentially Unstable Slopes; * Avalanche Hazards; and * Wildfire. Steep Slopes Attachment 5 is a slope analysis of the properties prepared by the Aspen/Pitkin County GIS Department. The slope analysis shows Lot 15 contains 2.2 acres. Approximately 90 percent of Lot 15 is comprised of slopes in excess of 45 percent. Most of the lot is comprised of slopes in excess of 50 percent. Attachment 5 shows that Lot 16 contains approximately 1.4 acres and approximately 75 percent of the land is comprised of slopes in excess of 45 percent. Only 1.3 percent of the lot has slopes of less than 30 percent. Lot 17 contains approximately .8 acres and is not as steep. However, approximately 59 percent of the lot has slopes between 30 and 45 percent and only 14 percent of the lot has slopes in excess of 45 percent. Lance Clarke AICP June 29, 2005 Page 4 The Pitkin County Land Use Code prohibits development on slopes in excess of 45 percent. In some cases, development is permitted on slopes varying between 30 and 45 percent. Typically, when slopes exceed 30 percent it is advisable to study land to see if other geologic hazards impact potential site development. Avalanche Hazards In January of 2004, Art Meats prepared the "Avalanche Mapping and Hazard Analysis Lots 15, 16, 17 Crystal River Park Subdivision Pitkin County" (see Attachment 6). Mears states that the lots are directly below steep, south facing slopes and cliffs. Slopes above the lots range in steepness from vertical to nearly vertical near the cliffs to less than 25 % in grade. Due to the solar exposure/sunny orientation, the slopes do not support a dense forest and existing vegetation is not sufficient to prevent snow avalanche formation during periods of snowpack instability. There are two avalanche paths which affect the properties, one is significantly larger and impacts Lot 15, while the smaller avalanche path primarily affects Lot 17. Page 8 of the Mears report depicts a map showing the red and blue avalanche zones (see Attachment 6). The Pitkin County Land Use Code prohibits any development in the red avalanche zone. The red avalanche zone severally impacts Lot 15. According to Mears' mapping, the upper portion of Lot 17 is in the red avalanche zone and most of the remainder of the Lot is in the blue avalanche zone. The Land Use Code prohibits development in the blue zone unless there are not alternative building sites on a property. In such a case development is permitted with structural mitigation devices. There is a small portion of Lot 17 located outside the blue zone, but it may be too small for development. A driveway accessing Lots 15 and 16 would have to cross the blue avalanche zone. Lot 16 is not impacted by avalanche hazards. Wildfire Hazard Attachment 7 is an October 2003, Wildfire Hazard Review prepared by Rocky Mountain Ecological Services Inc. (Eric Petterson). Wildfire hazard is severe due to the steepness of the three lots and the fact that fuels are continuous. Peterson recommends extensive mitigation measures to mitigate wildfire hazard. These recommendations related to vegetation, a modified structural design and construction standards, maintenance and access and utilities were modified for the conditions of the three lots. Lance Clarke AICP June 29, 2005 Page 5 The Pitkin County Land Use Code does not prohibit development in severe wildfire areas. Debris Flow, Rockfall and Potentially Unstable Slopes Attachment 8 is a May 26, 2005 report from HP Geotech entitled "Review of Debris Flow, Rockfall and Potentially Unstable Slope Impacts, Lots 15, 16 and 17 Crystal River Park Subdivision, Pitkin County, Colorado." The Report indicates all three lots could be the sites of debris flows associated with intense thunderstorm precipitation or unusually rapid snowpack melt. Channels are poorly developed on the alluvial fans on all three lots. A major debris flow could result in damage to buildings on the three lots and present a safety risk to occupants. In the opinion of Arthur Buck of HP Geotech, "the debris flow risk is not acceptable and mitigation to reduce the risk is recommended if the three lots are built on. Additional studies would be needed to evaluate the feasibility of mitigation and to develop mitigation plans if mitigation is shown to be feasible." Rockfall on the steep cliffs located 500 feet northwest of the three lots is an active geologic process under current conditions and the three lots are in the potential rockfall runout zone. According to HP Geotech, "a high velocity rockfall, similar to past rockfalls on Lots 15, 16 and 17, would result in severe damage to buildings and other facilities and will present a life safety risk to the occupants of the buildings." The runout zone appears to run down slope beyond the boundaries of Lots 16 and 17. Lot 15 is exposed to significant rockfall hazard as well. It is noted in Attachment 8 that rockfall blocks measuring 25 to 35 feet in size with estimated weights of 5,400 to 14,800 tons were observed on Lots 16 and 17" (emphasis added). As depicted by Attachment 5, the natural slopes of Lots 15 and 16 are 50 percent or greater. Cuts made in the steep hillside will have a relatively high potential for construction-related slope instability. Engineered plans would be required for any site grading and geotechnical studies are required to evaluate slope stability of Lots 15 and 16. Further study is needed to determine what measures would need to be taken to mitigate geologic hazards, if it is determined that any mitigation is feasible. What is clear is that if there are mitigation measures that are appropriate, they will be quite significant due to the severe constraints on the site. Outcrop stabilization is not a feasible mitigation method for rockfall hazard for the three lots due to the size and ~emoteness of the Lance Clarke AICP June 29, 2005 Page 6 source. A massive earth catching structure located up slope of the occupied buildings is the type of mitigation that may be feasible considering the size of past rockfall. The Pitkin County Land Use Code prohibits development in rockfall hazard areas unless there is not a feasible alternative site on a property. Extensive mitigation is required. In the case of the subject lots mitigation may not be feasible. CONSTRAINED SITE TRANSFERABLE DEVELOPMENT RIGHTS (Section 3-310-050) Ordinance #52 codifies the legislation related to constrained site transferable development rights. The following section addresses the standards for TDR eligibility in Section 3~310-053. Section 3-310-053 Standards and Criteria for TDR Eligibility. The Board may grant one or more transferable development right only upon demonstration that the lot meets the following criteria: Section 3-310.053.1 Preservation Site Undevelopable or Severe Restricted. The lots shall be determined by the Community Development Department to be undevelopable or severely restricted pursuant to the Pitkin County Land Use Code. Section 3-310.053.2 Equitable Mitigation. The Board shall determine that principals of equitable mitigation favor relief in the form of issuance of one or more Transferable Development Right(s). Section 3-310.053.3 Conservation Easements. TDRs recognized and certified pursuant to this section, may be obtained for property encumbered by a conservation easement provided that the conservation easement is granted in conjunction with the procedures contained in this section following a determination by the Community Development Department that the lot is undevelopable or is severely restricted and prior to the issuance or certification of the TDRs. Lance Clarke AICP June 29, 2005 Page 7 Section 3-310.053.4 Rural and Remote Zoning. Constrained site TDRs are not available for property zoned rural/remote. SUMMARY The section of the application summarizes why each of lots are not developable. Lot 15 is not developable because: the three The west side of the lot is in the red avalanche zone. Lot 16 Lot 17 is Vehicles on a driveway accessing the lot would cross a blue avalanche zone, potential debris flows and a severe rockfall hazard area. More than 89 percent of the lot is comprised of slopes in excess of 45 percent. The lot is subject to slope instability due to steep slopes. The lot is subject to debris flow and severe rockfall and wildfire danger. is not developable because: Approximately 75 percent of the lot is comprised of slopes in excess of 45 percent. Vehicles on a driveway accessing the lot would cross a blue avalanche zone, potential debris flows and a severe rockfall hazard area. The lot is subject to slope instability due to steep slopes. The lot is subject to debris flow and severe rockfall and wildfire danger. not developable because: A portion of the lot is located in the red avalanche hazard zone and most of the lot is in the blue avalanche hazard zone. Lance Clarke AICP June 29, 2005 Page 8 The lot is subject to slope instability due to steep slopes. The lot is subject to debris flow and severe rockfall and wildfire danger. There is a rock block which has fallen on the property that is as big as a small school bus. The following is a list of attachments for your reference. Attachment 1 Attachment 2 Attachment 3 Attachment 4 Attachment 5 Attachment 6 Attachment 7 Attachment 8 Attachment 9 Attachment 10 Crystal River Park Subdivision Second Addition recorded at Plat Book 3 Page 103 Amended Plat of Lots 3, 15, 16, 17, 18, 19 and 20 Crystal River Park Subdivision recorded at Plat Book 61, Page 14 Board of County Commissioner's Ordinance No. 8 of 2002 Granting Approval of the Vacation of High Drive and a Small Portion of Ruby Mountain Drive Adjacent to Crystal River Park Subdivision October 2, 2003 Pre-application Conference Summary Sheet Aspen/Pitkin County GIS Department Slope Analysis of Crystal River Park Subdivision Lots 15, 16 and 17 January of 2004 Report prepared by Arthur Mears P.E. Inc. "Avalanche Mapping and Hazard Analysis Lots 15, 16, 17 Crystal River Park Subdivision Pitkin County" October 2003, Wildfire Hazard Review prepared by Rocky Mountain Ecological Services Inc. May 26, 2005 report from HP Geotech entitled "Review of Debris Flow, Rockfall and Potentially Unstable Slope Impacts, Lots 15, 16 and 17 Crystal River Park Subdivision, Pitkin County, Colorado Pre-application Conference Summary Sheet Fee Agreement Lance Clarke AICP June 29, 2005 Page 9 Attachment 11 Letter Authorizing Submission of Land Use Application This letter demonstrates that 1041 Environmental Hazards impacting Crystal River Park Subdivision Second Addition Lots 15, 16 and 17 are quite severe. It is clear that the July of 2002 change in County land use policy was intended to subject lots such as these to land use approvals because site development endangers the health, safety and welfare of Pitkin County residents, visitors and emergency personnel. The applicant requests the Board of County Commissioners to issue one TDR to the applicant for each lot. Sincerely, DAVIS HORN INCORPORATED Satrang.1 ROCK CORNER CRYSTAL RIVER PARK SUBDIVISION PITKIN COUNTY, ¢OL ~RADO AMENDED PLAT OF LOTS SUBDIVISION, 3, 15, 16, 17, 2nd ADDITION, 18, PITKIN 19 & 20 , CRYSTAL RIVER PARK COUNTY, COLORADO N SCALE: 1%40' ./ PLAT OF LOTS 3 &5-201 ~NES ~ S~CE 'JAN. 28, 2OOb ~:22YM VJlEiN UUUNIY UL~KA KEbUKUEK [~u, Yo/ r, e ORDINANCE OF THE BOARD OF COUNTY COMI~ISSIONERS OF PITKIN COUNT¥~ COLO]~DO~ GRA.,NTING API'ROVAL OF Tt-~ VACATION O1~ HIGH DRIVE A.ND A SMALL PORTION O~ RUBY MOUNTAIN DRIV~ ADJ.~CENT TO LOT 3, CRYSTAL RWER PAH.K SUBDIVISION Orda~ee No.~d~ - 2002 RECITIAL8 1. CRV properties Ltd, LiaMlity Co, (Zo~ 15, 16, &17), Sl~wn & StephanJe ~,t~z (Lot 3); ~ K~I & Margarita Carrasco Do Tkumcr (Lot 1 g); P.~ter & Mary Louise Manardl (Lot 19); and David Clm'ne~i~ (Lot 20); ("Applicants") have applied to the pilkln County Board of Connty Commissioners ("BOCC") for approval of the vacation of High Drive and a small portion ofl~by Mountain Drive (formally Asl~n Driw) adja~nt to Lot 3. 2, The Crystal River Park ~lxlivialon Is localed south of Recls~one on the west side of Highway 133. 3, The Piikin County Planning and Zoning Commission r~vlewed th~ appli~tiou on January 15, ~.002, ~nd re¢ommond~:l appro~/sl. 4, Th.e BOCC heard the first msdin§ of'his application al a r~ular meeting on March 13, 2002, at which l~ne ~videnoe and t~sfimony w~rg pr~nted wilh respect to this application, 5. The BOCC heard the second r~ading of this application at a duly noticed public hearing on March 27, 2002, a.t which time additionil evidence and testimony wer~ presented wffh respect to this application, 6. The BOCC finds that the application me~s t~ applicable policies and regulations of~he ?itldn Counly Land Us~ Code, provided that eonditio,~s of this dcoumen~ am adh~d to. NOW THEREFORE lie IT RESOLVED by tl~ Pitldn County Board of County Commissioners that it does hgreby St, mt approval for the r~doction of the 25' High Drive easement to a mlniraam 14' driveway ~semont, and the vacation of a small portion of Ruby Mountain Drive adjncent to Lot ~, subjeot to the following conditions: 1. Thc Applicants shall adher~ to all msierial r~preseatations made in.tM application and ia publi~ meetings. 2. Ninoty (90) days fi'mn ~ approval of this Ordinance, the Applicant shall prepare and record a 24 X 36 inch mylar Plat. The plat shall also be submiited in a digital feramt for integration into the County C~ogrsphlo Information System (Gig). 3, Th~ 25' ~s~r~nt f0r High Drive shali be chaa//ed t6 mfl~ct tho Pitkln County minimum drlvev~y 14~ v4tdth ~ta~ldardo Tl~ls shall be reflected on the ~_mended phc .P ag~ 2 INTRODUCED, FIRST,READ, A~ THE REGULAR MEETING AND PUBLIC I~ARING ON 15TM DAY O~ MARCH, 2002, NOTICE OF PUBLIC HEAIL~G PUBLISHED l~ TR~ ASPEN TI3~E8 ON Y]~ 9TH DAY OF MARCH, 2002. AI~FROVED AND ADOPTED AFTER SECOND READING ON' T/~ 27TM DAY O1~ ~[ARCH, 2002. Pt~Usmm n_vr~a ~m,t~o~ m ~ Am,~ rr~s oN ~ 1~'~ nay ov ~L_. 2002. ORDINANCE SHALL HECOME EgF~:CI'IVE 30 DAYS AFI'F,R PTJB'LICATION FOLLOWI3rG F/NAL ADOS'lION BY THE BOARD O1~ COlYNTY COM3'/IiSIOI~il~. BOARD OF COUNTY COMMISSIONERS OF ?I2'KIN COL2Xq'Y, COLORADO P~i Y, ay-Clapp~ ' ' APPROVED AS TO FORM: APPROVED AS TO CONI ~NT: · CoUnty Attorney C~e #P170-Oi 272929202012 Cindy Hoube~ Community Development Di~or Page; g of 2 L 0CT-02-2003 THU 03:49 P~ P, O! PITKIN COUNTY PRE-APPLICATION CONFERENCE SUMMARY DATE: PROJECT: LOCATION: ZONE APPLICANT: PLANNER: I, O~ober 2, 2003 Satroag 1041 Hazard R~vicw and Conce~t~l Submission Crystal River Park Subdivision (Parc. el ID: 272929202004) Zach Satrang Tel: 970 686 6861; Fax: 686 6451 Rose Ann Sullivan 'feh 920-5482 Type of Application: ] 041 Hazard R'cvicw a~d Conceptual Submission. - Description of l~rojcct/Development: Applicant propos~ to establish access and a building cflvelopo for a new re~ide~lce. Areas in which the Applicant b requested to respond, types of report; · Section 3-60, Eflvirom'ncntal and Aesthetic Standm'ds · Section 3.70, Water Resources · Section 3-110, Improvements and Sexvices Section 9-110-0:51, Growth Mmmgement Exemption for pro- 1978 parcels s Section 3-80, 1041 Hazard Review 3.80.70 Wildfire (Low Wildfire) 3-80-50 Geologic (Slopes in F. xccss of 15% trod 30%, Potential Aval~¢hc) 3-80-i10 Wildlife (Elk Winter Rm~ge) 4. Review i~ before: Hearing Officer Public ltcnring: Yes, at fleering Officer. The applicant zlMII pos~ a public notice sign on thc property at leab~ 15 days prior ~o ~he hearing and shall mail notice ~o all adjacent property ovmcrs and mineral rotate owners at lenqt 30 prior to thc hearing with file mturfl address of ~hc Commtmity Development Deparlmem {cOpy of the notice to b~ obtained from tho Community Dev¢iopmem Depmtment). The names and addrosses sMll be those on thc cun'cnt tax records o£ PiLkin Couflty ~ they ~ppcar no more thmt 60 days prior ~o fl~e da~e of tho public heating. Will be referred to: Wildlili: biologist, Crystal River Caucus, Engineer, Crystal Rivet Park IIOA, 7, What fees Id WdgO:PO 000E IE '%°0 was the applicant ~equested to submit: Plm3niflg Office $2,100 Flat Fcc O',Ion-refundable, 'based an 10 l~s oF staff tim,.) Bngiflcer $525 Fla~ l;~c Wildlife B~ologist $500 Flat Fcc Publlv l~otlce Fcc $25 Il'oral Fee at ~qubmiflnl If the staff amc for this application exceeds 12 h~% thc Applicant will be charged at $210 per hour b~yand 10 hrs. Feez for llearing Officer at $135/hr. - Entire Application is required to be submitted di~itally oll a disk OF ~[J (acceptable Formats are: .tx~ .d0% ,wpd~ .rff~ .Jpeg~ ,pdf) \q 00T-02-2003 THU 03:50 PM FAX NO, P, O~ To appl},, submit nine (9) copies of thc foliowhtK intormaUon, unless othe~bc not~ (plea~ ~e doub~ sided ~iaK when poseJble): · L~r o~ ~t ad~sin8 C~o S~t[ons llst~ ~bove and dcscfib~n~ 24" X 36" fold~ Bite Pl~s (s~ at~h~ si~ plan requk~m~ts); ~ctln~cntafio~ofofAc~ss (2 ~pies); Wildf~ m~rt ~m local cx~ ~cumcn~tion of~w a~ when pa~J w~ crent~ (1 copy); l~ttcr from o~ atnhodzing mp~scnmttve, ii.liable (1 ~py); Docut~tntion or Ch~n of'l'iO~r~fo~own~s~p (from n gtlc comply or a~ey licensed in the State of Colorado) Including legal description (I ~py); A I~t ofadja~[lt To~ f~ t~ ~icw of tM app~caflon; Copy of Ihb p~-appli~don form (I cop)'); PLEASE NOTE: ~i~ ~re.al~lJcaflon ami nol binding on the (~uunt~. on curr~m zoni~ ztandar~ and tie ~t~ltc~t. ddditional tnformbtion ~ be required upon com~leN r~view of the application. ' · Ed Nd9iD:~O 000E Ia '~o0 I~599090&6: 'DH XU~ : l. lO~ ,,gend 2003 10ff Contours ~/~ USFS --- Ddves ~ 0-15% Slope -- Roads 15-30% Slope ~ Structures _ I Subdivision ~ ~ >45% Slope Parcels N 501 1001 W~E Feet S map/drawing/image is of the features depicted and is not a legal representation. The accuracy may change depending on the enlargement or reduction. I I I I I I I I I I I I I I I I I AVALANCHE MAPPING AND HAZARD ANALYSIS LOTS 15, 16, 17, CRYSTAL RIVER PARK SUBDIVISION PITKIN COUNTY Prepared For Mr. Zack Satrang ZTS Construction, Incorporated Prepared By Arthur I. Meats, P.E., Inc. Gunnison, Colo[ado January, 2004 I AVALANCHE MAPPING AND HAZARD ANALYSIS LOTS 15, 16, 17, CRYSTAL RIVER PARK SUBDIVISION I PITKIN COUNTY I I I Prepared For I Mr. Zack Satrang ZTS Construction, Incorporated I Prepared By I Arthur I. Mears, P.E., Inc. Gunnison, Colorado I January, 2004 I' ARTHUR I. MEARS, P.E., INC. i Natural Hazards Consultants 555 County Road 16 I I I I January 26, 2004 I Mr. Zack Satrang 507 Hemlock Drive Windsor, CO 80550 I Dear Mr. Satrang: The attached report has been prepared as discussed with Mr. Glen Horn of Davis-Horn, Incorporated. The report discusses potential snow avalanche hazard to Lots 15, 16, and 17 and discusses mitigation options where i appropriate. Please contact me if you have any questions. ! Sincerer, , I Arthur I. Meats, P.E. I Avalanche-control engineer o . I I I i Ma~z Wozting Avalanche$ Avalanche Control Engineering I 1 REPORT OBJECTIVES AND LIMITATIONS I The objectives of this report as follows: 1. To evaluate the terrain above lots 15, 16, and 17 for snow avalanche I potential; 2. To quantify the avalanche hazard; 3. To recommend avalanche mitigation, if it is necessary. I This report also has the following limitations, which must be understood by all those relying of the results: I t. The analysis is based on current (January, 2004) slope and vegetation conditions; changes to these conditions (e.g., fire, landslides, etc.) I the size of avalanche zones~ and invalidate the may increase starting conclusions; 2. Current design-magnitude (i.e., 100-year return period) conditions i have been evaluated which are consistent with the Pitkin County ordinance; even larger events are theoretically possible and could exceed the boundaries indicated on Figure 1; I 3. Final engineering details of avalanche protective structures, and design criteria for such structures are beyond the scope of this report; I 4. Evaluation of other geologic hazards, if any, including rockfall, debrfs slides and flows, is also beyond the scope of this study. I 2 AVALANCHE TERRAIN AND DESIGN-MAGNITUDE AVALANCHES 2.! Avalanche Terrain I Lots 15, 16, and 17 are located on the north side of the Crystal River and directly below steep, south-facing slopes and cliffs approximately 1 mile west of I Redstone (see location map, Figure 1). Slopes above the lots range in steepness from vertical or nearly vertical near the cliffs to less than 14° (< 25%) just above the upper part of Ruby Mountain Drive. Possible building sites would I be located above the of Mountain Drive. upper part Ruby Because of the sunny orientation, the slopes do not support a dense conifer I forest but are populated with deciduous species such as Gambel's oak (Quercus gambelii, and aspen (Populus tremuloides) and sparse populations of conifer species. The slopes are crossed by major vertical cliff bands and small cliff I outcroppings. These are separated by steep colluvial debris slopes which on which a thin soil has developed which enables development of the trees and I ' Starting zone - Steep area (generally greater than 30°) where avalanche start, accelerate, and increase in I 02/i7t2004 09:09 9705di3236 ART NEARS PAGE 01 other vegetation. The vegetation is not sufficiently dense to prevent snow avalanche formation during periods of snowpack instability. The two avalanche paths~ affecting the subject property begin within the steep colluvlal slopes north of the property. The western path (Path 1) is by far the larger of the two (Figure 2). It can start at approximately 8,700 feet, will fall over steep, broken terrain as it descends a distinct gully into the Subdivision and crosses through Lot 15. Analysis conducted for this study indicates this avalanche will stop, during extreme snowpack and weather conditions, well into the existing subdivision. A second, much smaller avalanche path (Path 2) can reach a portion of Lot 17, on the eastern part of the property. The largest avalanches in this path begin at roughly 7,900 feet in a sparsely-vegotated3 slope below the lower cliff band. Although a starting zone does exist, it is small (roughly 5,000 to 8,000 ft; [about 0_11 to 0.18 acre]), and narrow. Even the largest avalanches in this path will spread out into a broad, steep track above lot 17. They will lose energy quickly because they will encounter trees, other vegetation, and rocks, all of which will increase ground friction. 2.2 Design-Magnitude Avalanches The major and rare design-magnitude avalanches' which must be considered in land-use planning and engineering have not been observed at this location. Furthermore no field evidence for major avalanches wes observed. Given these data limitations the possible runout distances and hazard potential have been modeled by using a three-step procedure as follows: ]. The runout distance (or stopping point) wes computed through analysis of a large database of extreme avalanches in the Colorado mountains; a regression equation derived from this database was used to predict the stopping point in paths I and 2; 2. Given the stopping point derived in step '1 ,' avalanche speeds were computed along the path centerline profile; and 3. The boundary between the "red" and "blue" hazard zone was determined as that.point where potential impact pressures became less than 600 lbs/fr. 2 Avalanche path - The entire area in which an avalanche moves, including the starting zone, uack, and thc rlmout ~ Sparsely-vegetated slopa - Ifa slope is suff~elantly stcq~, a moderately de.se tree cove, such as the one in this path will not prevent all avalanches, oven the slab avalanches of~'entest c.o~eem i~ land-use ~innning and engineering. Desj~n-ma~imde avalanche - In Pitldn County. this avalanche has an estimated return period of 100 years (a c0~stant annual probability of 1/100 = 1%), Thc "100-yenr" ~um period is ~or~cct to the nenre~ order of magnitude, therefore thc ~ue ret'urn period lies between 30 and 300 years, approximately. Mitigation requires site-specific study to ensure design avalanche impact and/or stat c oads have been specified. Building design should require that facilities such as hot tubs which may be exposed to avalanches are not built in avalanche areas. Avalanche-free access to the houses should be provided. 5 INCREASE IN AVALANCHE HAZARD f development is planned in or near the avalanche blue zones some increase in avalanche risk to residents, guests, and other visitors will result simply because the total exposure time within the avalanche areas will also increase. Th s ncreased risk can be minimized if owners and guests are educated about the avalanche phenomena, heed all official avalanche warnings and advisories, and are prepared for self rescue. These additional steps are strongly recommended if the avalanche zones are to be used for residential development. Sincerely, Arthur I. Mears, P.E. (CO) Avalanche-control engineer PHOTO B. These houses in Sun Valley are built with the back comer facing the avalanche and splitting the flow. .egend N lOft Contours .~ Wamr $ Structures 0 150 300 Parcels I ~ I Feet s map/drawmghmage is a graphical representation of the teatures depicted and is not a legal representation The accuracy maychange depending on the enlargement or reduction. Copyright 2003 City of Aspen/Pitkfn Counb/ FIGURE 2. Avalanche map and propen'y boundaries from Pitkin County GIS database. Avalanche red and blue zones are shown and have been defined as discussed in Section 2 of this report. Many additional avalanche areas exist on this map but do not affect the property and are not shown. SCALE: 1' = 300' (1:3,600) I I I I i I I i I I I I I I i I I I TECHNICAL APPENDIX This technical appendix includes the following: 1. Statistical regression analysis through which runout distances were computed. 2. Sample avalanche profiles. 3. Avalanche-dynamics modeling output. These procedures were used to compute avalanche runout distances, speeds and impact energies, and to delineate the boundaries between red and blue hazard zones. Sheet1 Avalanche Profile and x/y coordinates C~stal R, Pa~ 1 Raw Da~ in feet Da~ in metem Segment Da~ ~ Y-feet X-metem Y-metem L-metem Ang - Deg Sum L 0 Avg Angle 0 878O 0 2677 230 8560 70 2610 ~ 97 43.7 97 43.7 490 8380 149 2555 96 34.7 193 39,2 575 8270 175 2521 42 52.3 236 41.6 680 8190 207 2497 40 37.3 276 40.9 715 8140 218 2482 19 55.0 295 41.8 885 8020 270 2445 63 35.2 358 40.7 1060 7900 323 2409 65 34.4 423 39.7 1140 7810 348 2381 37 48.4 460 40,4 1210 7780 369 2372 23 23.2 483 39.6 1260 7730 384 2357 ~o 22 45.0 504 39.8 1410 7560 430 2335 50 25.0 555 38.5 1480 7610 451 2320 26 35.5 581 38,3 1600 7550 488 2302 41 26.6 622 37.6 1775 7500 541 2287 55 15.9 677 35.8 1835 7490 559 2284 19 9.5 696 35.1 1930 7470 588 2277 /~ 30 11.9 726 34.2 2020 7450 616 2271 28 12.6 754 33.4 2055 7440 627 2268 11 15.9 765 33.1 ..~2205~7420 672 2262 I~ 46 7.~ 81~ 31.~ Crystal R. Park 1 Avalanche 2650 ~ [ 25 0 2250 Horizontal d~stance (m) I I I 484 particles start from top segment. ',. i! 5/ ~,".. /.." M ". ii i Ii!i ~,, \i ~/ C",, i/~' I ~ ~ / ~",,~ c:\plk\Crystal R Park 1.txt iPath drops: 415 m Friction mu = 0.30 log M/D = 2.40 Random R = 0.250 Alpha = 31.7 degrees 1188 particles deposited. I ! I I I I I I i I I · Front stops at X = 672 m ....................... Front speed (max = 28.3 m/s) ...... Mean speed (max = 28.5 m/s) .Deposition (not to scale) Exit and view distributions in your file c:\plk\results.txt ROCKY MOUNTAIN ECOLOGICAL NEPA' 'WILDLIFE'-VEGETATION--RECLAMATION. 'WETLANDS' 'PIdkNNING SERVICES, INC. ZTS Construction, Inc. 607 Hemlock Dr. Windsor, CO 80550 RE: 1041 Wildfire Hazard Review October 30, 2003 Dear Ms. Rubin Please submit this letter with your application to Pitkin County. I visited Lots 15, 16, and 17 in Crystal River Park, Pitkin County, on October 30, 2003 with Ms. Sherry Rubin, the owner's representative. Ms. Rubin is preparing a 1041 site review in anticipation of her client building a residential structure the property. The property and area around it are considered "Severe Hazard: Brush", due to the fact that the slope is greater than 20% (actual slope averaged 37%) and the fuels were continuous. Therefore, the following Vegetation Mitigations are recommended: I. Vegetation From the farthest point of the new construction, extending out to 20', all brush (oak, serviceberry, chokecherry, sagebrush, etc.) must be removed. It is recommended that clumps within 30' of the structure be irrigated to keep live fuel moistures high dudng the summer months. Oak brush shall be thinned to 5x the height of the remaining brushy plants within 70', and must be limbed up to 10' and all sprouts and understory shrubs must be removed and kept trimmed. Coniferous vegetation may remain, as long as it is separated by 5x the height of the tree or clump of trees. If some of these coniferous trees are fairly close to the house (<10 feet), then they may be considered to be an integral part of the structure, and all clearances will start at the furthest extent of the tree crown. Beyond 100', bush and shrubs must be thinned to 3 times the height distance to 150' from the dwelling, or to the extent of the 0222 BOBCAT LANE · REDSTONE · COLORADO · 81623 PHONE/FAX: (970) 963-2190 · CELL: (970) 309-4454 EMAIL: ERICPETTERSON~MSN.COM Lots 15-17 C~ystal Rt~r Park 1041 Wildfire Hazard Re~e~a October31, 2003 property boundary (whichever is the shorter distance). 4. All other vegetation must be kept to less than 1' (1 foot) in height up to 30' from any structures. A few scattered smaller shrubs can be left from 25' and beyond. All branches from trees and brush within the thirty-foot (70') perimeter shall be pruned to a height of ten feet (10') above the ground with removal of ladder fuels from around trees and brush. 5. All deadfall within a 100' perimeter of the house shall be removed. 7. All thinned oak brush, serviceberry or chokecherry stumps should be "painted" with Garlon® herbicide to prevent aggressive resprouting. 8. All branches that extend over the roof eaves shall be trimmed and all branches within fifteen feet (15') of chimneys shall be removed. Installed or native landscaping within 20' of the house must be irrigated, and not contain any brushy species- only grasses or forbs aro allowed. Flammable mulches (wood chips) are not recommended. Aspen trees are allowed near the house, as long as they are not within 10' of the structure, and are kept limbed to 10' (unless the trees aro less than 10' tall). No trees may be within 15' of any window. 10. The property owner shall be responsible for the continued maintenance of the above listed vegetation requirements. The following Modified Structural Design and Construction Standards aro recommended for any structures: I. Projections: Projections at the roofline (which includes, but aro not limited to: eaves, cornices soffits and roofs over open decks) shall be sheathed with materials approved for one-hour tiro-resistive construction. 2. For projections below the roofline (including, but not limited to: exterior balconies decks, porches, and bay windows which extend over a flat or sloped surface), the open space between grade and the underside of projections below the roofline shall be enclosed by solid, vertical walls. These walls shall be constructed with materials approved for one-hour fire-resistive construction on the exterior side of ~Rocky Mountain Ecological Services, Inc Lots 15-17 C~ystal River Park 1041 IVildflre Hazard Revie~v October 31, 2003 the wall, and shall extend from the top of grade to the underside of the floor decking or walls of the projection, OR: Any porch or deck or projection shall be void of vegetation below it, and areas below such projections shall be protected from accumulation of vegetation materials by placement of a vegetation barrier covered with rocks or gravel, or by coverage with concrete or stone. Walls underneath projections shall be constructed with materials approved for 1-hour fire resistive construction on the extedor side of the wall. Pillars or columns shall be of non-flammable materials, or if wood, made out of heavy log construction and treated with a fire retardant. The underside of any porch, deck or projection shall be sheathed in 1-hour fire resistive materials, or with fire-retardant treated wood. An alternative for a deck or porch is use of non-flammable hardscaping (flagstone, cement pad, etc.). Some planters may be in this area, but cannot contain trees (except aspen) or shrubby species. III. Exterior Walls and Siding Extedor walls and siding shall have a minimum one-hour fire resistive rating on the house and any other structures from ground level to roof line. Exterior doors shall be noncombustible or one and three-fourths inch (1' % ") solid wood. IV. Windows and Glass 1. Glazed openings shall be provided with closable, solid, exterior non-flammable shutters or shall be tempered glass. V. Foundations and Stilt Construction Foundations, skirting and crawl space openings shall be fully enclosed and constructed with materials approved for 1-hour fire resistive construction on the extedor sides of the walls and shall extend from the top of grade to the underside of the floor decking or walls. Stilt foundations shall be fully enclosed and constructed with materials approved for 1-hour fire resistive construction on the extedor side of the walls and shall extend from the top of grade to the underside of the floor decking or walls (not including porches, patios, etc.). VI. Roofing 1. All roofs shall be constructed with noncombustible roofing materials on a Class A roof assembly (see UBC 1997 Section 1504). 2. Roofs shall be installed as required by UBC 1997 Chapter 15 and shall have a minimum slope of 1:48. ~Ro~ky Mountain Ecological Services, Inc Lots ! 5- ! 7 C~ystal River Park 1041 [Vildfim Hagard P~iem November 20, 2003 3. All roof covetings shall have a surface that facilitates the natural processes of cleaning the roof. 4. Vents shall be screened with a maximum %" corrosive resistant wire mesh. VII. Maintenance 1. Roofs and gutters shall be kept clear of debris. 2. Yards shall be kept clear of all littler, slash and flammable debris. 3. All flammable materials (including firewood) shall be stored on a parallel contour a minimum of 30' from any structure, or within a separate structure. 4. Weeds and grasses within a twenty-foot (20') perimeter shall be maintained to a height of not more than six inches (6"). Viii. Miscellaneous Fences shall be kept clear of brush and debris, and must have at least a 3" gap between the fence and the main structure. Non-flammable, or treated wood fencing material is recommended within 20' of any structures. 2. Any outbuildings or additional structures shall adhere to the same standards as the main house. 3. Each structure shall have a minimum of one ten-pound ABC fire extinguisher. Addresses shall be clearly marked with 2" non-combustible letters and shall be visible at the primary point of access from the public or common access road and installed on a non-combustible surface. 5. Fuel tanks shall be installed underground with an approved container. '~Ro~ky Mountain Ecological Services, Inc 6. Propane tanks shall be buried, or installed according to NFPA 48 standards and on a contour away from the structure with standard defensible space vegetation mitigation around any aboveground tank (i.e. no shrubs within 25' of the tank). Any wood enclosure around the tank shall be constructed with materials approved for two (2) hour fire-resistive construction on the extedor side of the walls. 4 Lots 15- ? 7 C~7stal River Park 1041 Wildfire Hagard Revie~v November 20, 2003 IX. Access Thin shrubs (oak, chokecherry, serviceberry, sagebrush) to 3 times height along the driveway back 25' on either side. Stumps must be painted with Garion herbicide to prevent aggressive re-sprouting. No shrubs or conifers are allowed within 10' of the driveway. Aspen are permitted within 10' of the driveway, but must be pruned to 10' above the ground. 2. All other vegetation must be kept to 6" or less within 10' of the driveway. 3. The turn around space at the beginning of the driveway (next to the fire hydrant) will be close enough for an emergency vehicle turn around. Water Supply Any fire department recommendation for individual structure water supply and storage shall be accessible to fire department vehicles from the extedor of the structure through a Fire Department approved mechanism (such as a fire hydrant). The amount of storage capacity shall be determined by the fire protection district with a minimum of one thousand (1,000) gallon storage capacity per structure. All structures greater than 5,000 square feet in size shall be required to install in- house sprinkler systems that meet the standards of the local fire protection district and the Uniform Building Code. At building permit submittal, the local fire protection district may require smaller structures to be sprinkled due to hazard considerations, emergency access difficulties and lack of proximity to fire protection services. XI. Utilities 1. Utility lines shall be buried. XII. Building Envelope and Wildfire Hazard Area Delineation Concurrent with building permit submittal, a site plan that meets the requirements of section 5-70-040 shall be submitted that delineates all development within a building envelope (wildfire mitigation, and creation of defensible space, may occur outside the building envelope). Wildfire hazard areas shall be delineated within the building envelope consistently with the definitions of section 3-80-070A. 1.; provided that, in the case of varying hazard levels within the building envelope, it shall be sufficient to label the entire envelope with the highest level hazard. The building envelope and a hundred-foot radius surrounding all structures shall be clearly labeled as either: Iow hazard, medium hazard; or severe hazard. ~ocky Mountaifi Ecological Services, Inc 5 Lots 15-17 C~ystal River Park 104 ! IVildfire Hazard Review Navember 20, 2003 The standards stated in 3-80-070 Wildfire Hazard Areas, has been slightly modified for the conditions at this property. Thank you for this opportunity to comment on this property, and please feel free to call if you have any questions. Sincerely, Eric Petterson Principal Ecologist Rocky Mountain Ecological Services, Inc. ~ky Mountain Ecological Services, Inc i:ecla HEPWORTH - PAWLAK GEOTECHNICAL May 26, 2005 Zachariah Satrang 605 Hemlock Drive Windsor, Colorado 80550 Job No.105 426 Subject: Review of Debris Flow, Rockfall and Potentially Unstable Slope hnpacts, Lots 15, 16, and 17, Crystal River Park Subdivision, Pitkin County, Colorado. Dear Mr. Satrang: As requested, we have conducted a review of the potential debris flow, rockfall and potentially unstable slope impacts to the subject property. The study was conducted in accordance with our Professional Services Agreement letter to you dated May 17, 2005. A reco~maissance to observe the potential impact conditions to the property was madeon May 5, 2005. We have also reviewed published regional geologic literature and regional geologic mapping, and the Avalanche Mapping and Hazard Analysis of Lots 15, 16, and 17 of the Crystal River Park Subdivision, prepared for you by Art Mears (2004). This report summarizes our findings and presents our conclusions and recowanendations. SITE CONDITIONS Lots 15, 16, and 17 are located on a series of coalescing alluvial fans down slope of prominent sm~dstone cliffs in the northwesternpart of the Crystal River Park Subdivision. The vegetation on the lots consists of native grass and weeds with scrub oak, aspen and scattered conifer trees. The natural slopes on the lots are generally down toward the southeast, with the exception of Lot 15 which has steep slopes down to the southwest adjacent to a drainage that runs through the southwest part of the lot. The slopes on the lots range in steepness from about 25% to 30% on Lot 17, up to about 50% on Lot 16, and up to about 75% in the central part of Lot 15. An ephemeral drainage runs through the northeast part of Lot 17 and a deeply incised drainage rm~s through the southwestern part of Lot 15. Large sandstone rockfall blocks, some up to 35 feet in size, are present on all three lots. GEOLOGIC SETTING The Crystal River Park Subdivision is located on a topographic bench on the west side of ~1 0 the Crystal River valley near the southeast limb of the Grand Hogback monocline. The Parker 303-841-71t9 * Colorado Springs 719-633-5562 · Silverthorne 970-468-1989 -2- Grand Hogback is a geologic structure that was fom~ed during the Lararnide orogeny about 40 to 80 million years ago. The near surface soils in this part of the Crystal River valley consist mainly of alluvial fans and colluvium on valley sides and varying ages of river alluvium in the valley bottom adjacent to the Crystal River. Lots 15, 16, and 17 are located on a series of coalescing alluvial fans in the west part of the Crystal River Park Subdivision. Lot 15 is located about 300 feet southeast of a fan head and the main drainage on the fan runs through the southwestern part of the lot. Lot 17 is located about 600 feet southeast of a fan head and an ephemeral drainage runs through the eastern side of the lot. The area is underlain by the Penman and Pennsylvanian-age Maroon Formation which crops out on steep cliff faces on the west sides of the valley above the project site (Tweto and Others, 1978). The Maroon Formation consists of red, interbedded sandstone, conglomerate and siltstone. A northwest trending high-angle fault, downthrown on its east side is located on the hillside about 1,200 feet west of the project site. The fault is geologically old and is not considered to be potentially active. The closest geologically young fault zones to the property with known or suspected post-glacial activity, movement within about the last 15,000 years, and considered capable of generating large earthquakes, are the Williams Fork Mountain fault zone located about 77 miles to the northeast and the southern section of the Sawatch fault zone located about 62 miles to the southeast (Widmam~ and Others, 1998). GEOLOGIC HAZARDS ASSESSMENT Potential geologic hazards that could affect development on Lots 15, 16, and 17 are debris flows, rockfall, potentially unstable slopes and snow avalm~che. The snow avalanche impacts for the three lots have been addressed by Mears (2004) and are beyond the scope of our review. Potential debris flow, rockfall, and unstable slope impacts that could affect the three lots are discussed below. Debris Flows: The alluvial fans on the three lots are geologically young aud could be the sites of debris flows associated with intense thunderstorm precipitation or unusually rapid snowpack melt. Chmmels are poorly developed on the fans on the three lots and it is not possible to predict the path that a debris flow or flood will take as it travels down the fans. Without long-term observations, which are not available, it is not possible to estimate statistical recurrence probabilities for debris flow or flood events on the alluvial fans with a high level of confidence. Considering the regional setting, the statistical recurrence of Job No.105 426 -3- major debris flows in the alluvial fans in the three lots is probably in the range of 50 to greater than 100 years. A major debris flow event could result in damage to buildings on the three lots and present a safety risk to the occupants of those buildings. In our opinion, the debris flow risk is not acceptable and mitigation to reduce the riskis recommended if the three lots are built on. Additional studies will be needed to evaluate the feasibility of mitigation and to develop mitigation plans if mitigation is shown to be feasible Rockfall Potential: Rockfall on the steep cliffs located about 500 feet northwest of the three lots is an active geologic process under current environmental conditions and, in our opinion, the three lots are in the potential rockfall runout zone. Rockfall in the vicinity of Lots 15, 16, and 17 likely has a statistical recurrence probability greater than 100 years. However, a high velocity rockfall similar to past rockfalls on Lot 15, Lot 16, or Lot 17 would result in severe damage to buildings and other facilities and will present a life safety risk to the occupants of the buildings. During our field reconnaissance of the property, several large rockfall blocks measuring 25 to 35 feet in size with estimated weights of 5,400 to 14,800 tons were observed on Lots 16 and 17. The runout zone appears to extend down slope beyond Lots 16 and 17. In our opinion, the rockfall hazard to the eastern part of Lot 16 and all of Lot 17 is severe and will likely require extensive mitigation. The rockfall potential on Lot 15 does not appear to be as severe as that on Lots 16 and 17, however, Lot 15 is exposed to a significant rockfall hazard. Outcrop stabilization in the source area will not be a feasible mitigation method for the three lots due to the size and remoteness of the source from the property. A massive earth catching structure located up slope of the occupied buildings is the type of mitigation that may be feasible considering the size of past rockfall. Additional studies will be needed to evaluate the feasibility of using a massive earth catching structures for rockfall mitigation. Construction-Related Slope Instability: The natural slopes on the hillside of lots 15 and 16 are 50% or greater. Cuts made into the steep hillside deposits on these lots will have a relatively high potential for construction-related slope instability and engineered plans will be required for site grading. Site specific geotechnical studies will be required to evaluate the stability condition of the hillside deposits on Lots 15 and 16 to develop appropriate grading criteria. LIMITATIONS This study was conducted according to generally accepted engineering geology principles and practices in this area, at this time. We make no warranty either express or implied. The conclusions and recommendations submitted in this report are based on our field Job No.105 426 ~ -4- observations, previous regional geologic studies and mapping, and our experience in the area. This report has been prepared exclusively for our client to evaluate the potential influence of the geology on the proposed development. The infom~ation is suitable for preliminary evaluations. We m'e not responsible for technical interpretations by others of our infom~ation. Additional geologic assessments and geoteclmical analyses will be needed to evaluate if debris flow and rockfall mitigations are feasible on the three lots. If you have any questions or need further assistance, please let us l-a~ow. Respectfully Submitted, HEPWORTH - PAWLAK GEOTECHNICAL, INC. Arthur D. Buck Engineering Geologist Reviewed by: Steven L. Pawla cc: Davis-Horn, Inc. - A~ REFERENCES Mears, Arthur 1., 2004, Avalanche Mapping and Hazard Analysis, Lots 15, ! 6, ! 7, Crystal River Park Subdivision, Pitkin Coio~ty, Colorado: Prepared for Zack Satrang, ZTS Construction, Inc., January, 2004. Tweto, Ogden and Others, 1978. Geology iliaR of the Leadville ] °X 2 ° Quadrangle, Northwestern Colorado. U.S. Geological Survey Map 1-999. Widmam~, Beth L., Kirkham, Robert M., and Rogers, William P., 1998. Preliminary Quaternary Fault and Fold Map and Database qf Colorado. Colorado Geological Survey, Open File Report 98-8. .lob No,105 426 C.-~'tOGlq . .]un 20 OS 02:32p YUSEM / HORI'~ PITKIN COUNTY PRE-APPIgICATION CONFERENCE SUMMARY PROJECT: Crystal River ParE, Lots 15,16, 17 LOCATION: Crystal Valley APPLICANT: Zack Satrang REPRESENTATIVE: Glenn Horn DATE: June I, 2005 9'70 925-5180 PID#??? ( please provide) PH: 925-6587 E-MAIL: ghorn~rof, net LancZ'~"arke,~.~,~ 920-5452 PLANNER: .> Type of Application: Request for..C,o, nstrained Ldt TDR (s) Description of ProjectfDevelopment: The Applicant is proposing the folloadng approval: 1. Determination that Lots I5, 16, and 17 are "Constrained" and eligible for a grant of TDR(s). Land Use Code Sections to be addressed in letter of request (application'): Section 3-310-050: Constrained Site Transferable Development Rights (Ord. # 052-2004) Staff will refer the application to the fallowing agencies: Crystal Caucus, Crystal River Park HOA Review by: Corrmmnlry Development Director for Determination. BOCC for possible Grant of TDR(s) Public Hearing: No. FEES: $1,006 (make check payable to "Pitkin County Treasurer") · Planning Office flat fee: $896 (non-refundable; based on 4 hours of staff time; ifstaffreview time exceeds 5 hours, the Applicant will he charged for additional time above the 5 hours at a rate of $224faour) · Clerk flat fee: $110 To apply, submit 7 copies of the following information, unless noted otherwise: 1. Summary letter explaining the request, providing background on prior approvals and perm/ts, and addressing compliance with the Code sections listed above. 2. Documentation of Lots' status as "undevelopable or severely restricted" under Land Use Code. 3. Proof o f ownership of subject property 4. Parcel description, including legal description and vicirdty map 5. Total fee for review of the application 6. Signed fee agreement (2 copies) 7. Consent from owner(s) to process application and anthorizing the representative (1 copy) 8. Copy of this preapp form (1 copy) NOTES: PLEASE SUBMIT TWO-SIDED COPIES OF ALL APPLICATION MA TERIALS (IF POSSIBLE). ALL MAPS SHALL BE FOLDED. This pre-application conference summaty is advisory in nature and not binding on the County- The iqformation provided in this summary is based on current zoning standards and staff's interpretations based upon representations of the applicant. Additional information may be required upon a complete review of the application. · ~un 20 05 02:32~ YUSE~ ? HOrN 9?O 925-St80 p.3 PITKIN COUNTY COMMUNITY DEVELOPMENT DEPARTMENT AGREEMENT FOR PAYMENT OF LAND USE APPLICATION FEES P[TKIN COUNTY (hercinat'tcr COUNTY) and 7'.'-~ ~ ~Ttun. t.-'rtot'~ '~_~C.... (hereinaD. er APPLICANT) AGREE AS FOLLOWS: 1. APPLICANT has submitted to COUNTY an application for C...x.~ ~ ~- ~..e..~g.~--'e,'l- (hereinafter, THE PROJECT). 2. APPLICANT understands and agrees that Pitkin County Ordinance No~ 011-2005 establishes a fee structure for land use applications and the payment of all processing fees is a condition precedent to a determination of application completeness. The tee structure is based on the County's policy that development shall pay, in full. the cost of development review in Pitldn County. Fees have been set to be consistent and fair to the public and to reflect the expense incurred i.t providing such services to the public. 3. APPLICANT and COUNTY agree that becatkse of the size, nature or scope of the proposed project, it may not be possible at the time of application to ascertain the full extent of the costs involved in processing the application. 4. APPLICANT and COUNTY agree that fees charged for the processing of land use applications shall accumulate if an application includes more than one type of land use review. 5. COUNTY and APPLICANT further agree that it is impracticable for COU~NTY staffto complete processing or present sufficient information to the Planning Commission and/or Board of County Commissioners to enable the Planning Commission anti, or Board of County Commissioners to make legally required findings for project approval, unless current billings are paid in full prior to decision. 6. Therefore, APPLICANT agrees that in consideration of the COUNTY's waiver of its fight to collect full fees prior to a determination of application completeness, APPLICANT shall pay a base fee in the amount ors ~,C>O~ which is based on~"~ hou-s of staff time, and if actual time spent by staffto process the application ~xceeds the average number of hours by more than 20%, then the COUNTY will bill the APPLICANT quarterly for the additional time spent. Such periodic payments shall be made within 30 days of the billing date. APPLICANT further agrees that failure to pay such accrued costs shall be grounds for suspension of processing. PITKIN COUNTY APPLICANT Cindy Houben Community Development Director Effective 5/25/05 Mailing Address: , Jun 20 OS 02:32p YUSEM / HORM 970 925-5180 ZACK SATRA~G ZTS CONSTRUCTION INC. 607 HEMLOCK DRIVE WINDSOR, COLORADO 80550 June 20, 2005 Lance Clarke AICP Pitkin county community Development Department 130 South Galena Street Aspen, Colorado 81611 Re: SATR/tNG CONSTRAINED LOT APPLICATION This letter authorizes Davis Horn Incorporated to prepare a Request for a Constrained Lot Review for three lots located in Crystal River Subdivision Second Addition (.Lots.15, 16 and 17) owned by ZTS Construction Incorporated. Davis Horn Incorporated and Tom Smith will represent ZTS Construction Incorporated in the land us~ review, process. Sincerely, COiPORATED Clarke.325