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HomeMy WebLinkAboutbocc.res.131.2002 RESOLUTION OF THE BOARD OF COUNTY COMMISSIONERS OF PITKIN COUNTY, COLORADO, GRANTING APPROVAL OF THE FREI/CRYSTAL RIVER FLATS SUBDIVISION AND GMQS EXEMPTION FOR CREATION OF AN OPEN SPACE PARCEL, 1041 HAZARD REVIEW AND CONCEPTUAL SUBMISSION Resolution No.131 -2002 RECITALS 1. Albert R. Frei("Applicant")has applied to the Pitkin County Board of County Commissioners (`BOCC')to consider a Subdivision Exemption for the Creation of an Open Space Parcel pursuant to Section 3-190-050 of the Land Use Code. 2. The Applicant has further applied for 1041 Hazard Review approval to establish a building envelope on the remaining parcel (Lot B)that will encompass a single-family residence. 3. The property is located adjacent to Crystal River Country Estates along Highway 133 as more specifically described in Exhibit A. 4. The property is zoned RS-30 and contains a total of 75.674 acres. 5. The Planning and Zoning Commission considered this application on June 4, 2000, and recommended approval. 6. The BOCC heard this application at a duly noticed public hearing on July 24,2002, at which time evidence and testimony were presented with respect to this application. 7. The BOCC determined that purchase of the open space parcel (Lot A) is in the common interest of Pitkin County and its residents. 8. The BOCC has determined that the proposed development meets the criteria established in Sections 3-190-050, 3-60, 3-70, 3-80, and 3-110 of the Land Use Code, and therefore found the proposal to be appropriate. NOW THEREFORE BE IT RESOLVED by the Pitkin County Board of County Commissioners that it does hereby approve the Frei/Crystal River Flats Subdivision Exemption for the Creation of an Open Space Parcel, 1041 Hazard Review and Conceptual Submission subject to the following conditions,which shall run with the land and be binding on all successors in interest. 1. The applicant shall submit a 1041 Site Plan and Subdivision Exemption Plat as described in Section 5-70-40 and 5-40 of the Land Use Code to the Community Development IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIillO 8g090 0009:331; Resolution No. -2002 Page 2 Department for approval and recording,prior to submission of any building permit application. The site plan shall be amended so that the public access easement on the southwest comer of Parcel B reads as follows; "Access and Trail Easement as recorded at Reception No. " (64mnaE. 4Ivsu�6 £) The site plan shall also be submitted in digital format for integration into the County's GIS system. 2. Applicant shall not grant any other access easement authorizing motorized use or a use that is otherwise inconsistent with Pitkin County Trails regulations found in Title 12 of the Code. 3. The Applicant shall adhere to all conditions and material representations made in the application and public meetings except as amended herein. 4. Prior to issuance of a septic permit,the applicants shall provide documentation to the Environmental Health Department as to the quantity and quality of the water on the property. 5. A septic permit shall be obtained from and approved by the Environmental Health Department,prior to issuance of a building permit. The septic system shall be located within the designated building envelope. The system must comply with all minimum horizontal setback requirements between its components and physical features. A qualified professional engineer must design the system. 6. The Applicants shall obtain an access permit from the Pitkin County Engineer prior to building permit submission. The Applicant shall also provide proof of access to Parcel B across the Crystal River Country Estates Subdivision prior to issuance of a building pemut. 7. A fireplace/woodstove permit shall be approved by the Environmental Health Department prior to issuance of a building permit. 8. The applicant shall comply with the following landscaping and wildfire defensible space mitigation standards: A. Brush, debris, and non-ornamental vegetation shall be removed within a minimum 10 foot perimeter around the structure. B. For a distance of 15 feet around all structures,establish and maintain vegetation at 6 inches or less. This can be done with mowed grass,low growing perennials or some type of hard scape(e.g. sidewalk,rock mulch,pavers). Woody vegetation should not be planted within this perimeter and no flammable materials should be stored within the perimeter. C. For a distance of 30 feet around all structures, grass shall be maintained at a height of six inches or less. IIII IIII IIIIII IIIIIII III IIIII IIIIIII III 490 2 09:33R SILVIP DAVIS PITKIN COUNTY CO R 0.00 D 0.00 Resolution No.131 -2002 Page 3 D. Vegetation shall be reduced to break up the vertical and horizontal continuity of the fuels a minimum of a 30 foot perimeter around the structure. E. For a distance of 100 feet around all structures,thin existing conifers so that all the crowns are no closer than 10 feet as measured from the outermost branch. F. Spacing between clumps of brush and vegetation within the 30 foot perimeters shall be a minimum of two times the height of the fuel. Maximum diameter of the clumps shall not exceed 10 feet. All measurements shall be from the edges of the crowns of the fuel. G. All branches from trees and brush within the 30 foot perimeter shall be pruned to a height of 10 feet above the ground and ladder fuels from around trees and brush shall be removed. H. All branches which extend over the roof eaves shall be trimmed and all branches within 15 feet of the chimneys shall be removed. I. All deadfall within the 100 foot perimeter shall be removed. J. The applicant shall be responsible for the continued maintenance of the defensible space vegetation requirements. 9. The applicant shall comply with the following additional wildfire mitigation standards: A. Roofing: New roofs shall have a non-combustible roof covering on a class A, assembly roof system. Wood shake/shingle roof coverings and flat roofs (up to a 3:12)pitch are prohibited. B. Vents shall be screened with corrosive resistant wire mesh with mesh ''/a inch maximum. C. Roofs and gutters shall be kept clear of debris. D. Yards shall be kept clear of all litter, slash,and flammable debris. E. All flammable materials shall be stored on a parallel contour a minimum of 15 feet away from any structure. F. Weeds and grasses within the 10 foot perimeter shall be maintained to a height not more than 6 inches. G. Firewood/wood piles shall be stacked on a parallel contour a minimum of 15 feet away from the structure. H. Swimming pools shall be accessible to Fire Department vehicles. I. Fences shall be kept clear of brush and debris. J. Wood fences shall not connect to the structure. K. Any outbuildings or additional structures shall adhere to the same standards as structures. L. Fuel tanks shall be installed underground with an approved container. M. Propane tanks shall be installed according to NFPA 48 standards and on a contour away from the structure with standard defensible space vegetation mitigation around any above-ground tank. Any wood enclosure around the tank shall be constructed with materials approved for 2 hour fire-resistive construction on the exterior side of the walls. N. Each structure shall have a minimum of one 10 pound approved ABC fire extinguisher placed in a visible and accessible location. O. Addresses shall be clearly marked with 2 inch non-combustible letters and shall be visible and installed on a non-combustible post. P. Utility lines shall be buries' IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIRII IIIII 4099ef g e .33qIIIIIII COUNTY c0 0.00 D 0.00 Resolution No.L�L-2002 Page 4 10. The applicant shall comply with the following measures to mitigate impacts to wildlife: A. The Applicant must comply with all of the general standards as described in Land Use Code Section 3-80-080 A. B. Dogs are prohibited on the property as per Land Use Code Section 3-80-080 B.5. with the exception of a canine companion assistance dog solely for the personal use of Albert Frei. C. No fencing shall be allowed outside of the approved building envelope. D. The building envelope shall avoid Crystal River riparian area. E. An orange construction fence must be placed around all approved construction areas to prevent unnecessary vegetation disturbance during construction. " /oak Sou F. Installation and use of approved bear proof trash containers is required on the property/' °�o�e Mj The Pitkin County Wildlife Biologist prior to issuance of Certificate of Occupancy shall'00 require verification of this condition. G. Native vegetation shall be maintained outside of the approved building envelope as long as it complies with the wildfire mitigation stated above. Any areas disturbed outside the envelope must be revegetated with native plants according to a revegetation plan approved by the County. H. Construction activity is prohibited from December 1 through April 15. 1. Fruit bearing trees and shrubs should be avoided in any landscaping within 20 feet of structures. J. Standing dead cottonwoods should be retained whenever possible outside of the defensible space requirements as per Land Use Code Section 3-80-080 A.13. K. Ponds are permitted outside the approved building envelope only if the Pitkin County Wildlife Biologist grants permission prior to construction. 11. No development, including grading, landscaping,vegetation removal or disturbance, shall occur outside of the approved building envelope, except for utility and driveway extension and maintenance,and as may be necessary to implement the wildfire mitigation measures required elsewhere in this document. 12. Prior to commencement of any earthmoving or construction activity, the Applicants shall stake the corners of the building envelope and install construction fencing around the perimeter of the building envelope. The fencing shall remain in place until issuance of certificate of occupancy. 13. Prior to application for building permit the applicant shall provide for review and approval of the County Engineer a trip generation and construction trip generation study for any free market residential structure of 5,000 gross square feet or greater. A traffic-engineering consultant hired by the applicant and pre-approved by the County Engineer shall develop this study. 14. The applicant shall adhere to the recommendations made in the Geologic Report written by Collins and Associates dated January 23, 2002(see Exhibit B). Geologic mitigation shall include but is not limited to the construction of a berm to the north and northeast of the IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIe 08/O9 of 12 0 2 09:33A Resolution No.13i -2002 Page 5 building envelope to protect against potential rockfall hazard as well as positive drainage design and channeling of drainages. The County Engineer prior to submission of a building permit shall approve a geologic mitigation plan prepared by a certified engineer. 15. Open Space and Trails shall be allowed to place customary trail signage on established easements through Parcel B. 16. The Applicant shall provide a new easement on the southwest comer of Parcel B for access from Highway 133 to the easement for Parcel A. Documentation of this easement shall be verified by Community Development prior building permit submission. 17. Pursuant to Ordinance No. 022-2000, the Applicant is subject to the Fair Share Requirements and shall pay a road impact fee as calculated at the same time as building permit issuance. 18. Floor area shall be limited to 5,750 square feet exempt from growth management or use of TDRs. Floor area shall be calculated based on the definition in effect at the time of building permit submittal. 19. Statutory vested rights for the approval contained herein are granted pursuant to the Pitkin County Land Use Code and Colorado Statutes, subject to the exceptions set forth in Pitkin County Land Use Code, § 4-140 and C.R.S., § 24-68-105. The statutory vested rights granted herein shall expire on July 24, 2005. 11111 Jill 1111 08995 90a2 00 33p SILMA DAVIS PITKIN COUNTY CO R 0.00 D 0.00 Resolution No.0/ -2002 Page 6 NOTICE OF PUBLIC HEARING PUBLISHED IN THE ASPEN TIMES ON THE 221°D DAY OF JUNE 2002. APPROVED AND ADOPTED ON THE 24TH DAY OF JULY,2002. VESTED RIGHTS NOTICE PUBLISHED ON THE SR�DAY OF �1J�'IAST2002. ATTEST: BOARD OF COUNTY COMMISSIONERS OF PITKIN COUNTY, COLORADO yn e R. Dean, Patti Kay Clapp De uty Clerk and Recorder Chair Date: APPROVED AS TO FORM: APPROVED AS TO CONTENT: G/C Johy E Chridy1floulben, C unty Attorney Community Development Director Case#P044-02 PID#264909400003 IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIiIIIIIIIIIIIIIIIII 87090 of 12 02 09:33n 0 D 0.00 I31 - z &wi$rT A IILVIIIIIIIIIIIIIIIIIIIIIIII III IIIIIII III IIIIIIIII IIIIDAVIS PITKIN CC 08�09002 012 9:33A Y Co R 0.00 D 0.00 A PARCEL OF LAND PREVIOUSLY DESCRIBED IN BOOK 381, PAGE 283, FILED WITH THE PITKIN COUNTY CLERK AND RECORDER SAID PARCEL OF LAND SITUATE IN THE EI/2SEl 4, SECTION 9, TOWNSHIP 9 SOUTH, RANGE Be WEST OF THE 6TH PRINCIPLE MERIDIAN, COUNTY OF PITKIN, STATE OF COLORADO; BEING MORE PARTICULARLY DESCRIBED AS FOLLOWS: BEGINNING AT THE EAST SIXTEENTH CORNER OF SAID E1/2SE1/4 SECTION 9 AND 16 BEING A BLM CAP IN PLACE,. THENCE N 00034 39" W ALONG THE WESTERLY LINE OF SAID E112SE114 2075.99 FEET TO A POINT ON THE SOUTHERLY RIGHT-OF-WAY LINE OF STATE HIGHWAY N0. 133, A REBAR AND CAP IS 31143 IN PLACE,. THENCE DEPARTING SAID WESTERLY LINE A POINT ON THE N 5B'00" E ALONG SAID SOUTHERLY RIGHT-OF-WAY LINE 855.23 FEET TO NORTHERLY LINE OF SAID EI/2SE1/4 A REBAR AND CAP IS NO. 31143 IN PLACE,' THENCE DEPARTING SAID RIGHT-OF-WAY LINE N 89°5248" E ALONG SAID NORTHERLY LINE 667.34 FEET TO THE EAST CORNER OF SAID SECTION 9, A BLM CAP IN PLACE, THENCE DEPARTING SAID NORTHERLY LINES 00°36'55" E ALONG THE EASTERLY LINE OF SAID SECTION 9, 2638.76 FEET TO THE SOUTHEAST CORNER OF CAP L'V PLACE• THENCE DEPARTING SAID EASTERLY LIVES 89°59 4 SECTION OF BEGINNING. ,,9 A BLM , ALONG 7HE SOUTHERLY LINE OF SECTION 9, 1319.8E FEET TO THE CONTAINING 75.674 ACRES MORE OR LESS; HAVE BY THESE PRESENTS LAID OUT, PLATTED AND SUBDIVIDED THE SAME INTO LOTS AND BLOCKS AS SHOWN I THIS PLAT UNDER THE NAME AND STYLE OF CRYSTAL RIVER FLATS EXEMPTION AND DO HEREBY DEDICATE TO THE PUBLIC ALL RIGHTS-OF-WAY AND EASEMENTS SHOWN HEREON FOR PUBLIC USE. COLLINS & ASSOCIATES GEOL061CAL ANo NAnMAL RESOUACE CM TANrS P.O. Box 23 - 1116 NIINEOTA pPIVE 53LT, COt.OPADO 81652 PHONE/FAX (970) 876-5400 boeol@rof.net January 23, 2002 Francis Krizmanich 0079 light Hill R Use Planning I 1111111111111111111111111111111111111111111111111111 Page:90 f 12 IA DAVIS PITKIN COUNTY CO 02 09.33p Snowmass, Colorado 81654 a e.ee o e.0e RE:FRET PROPERTY,CRYSTAL RIVER FLATS,SEIzZEfii SEC.9,T.9 S.,R.88 W.,PI770N COUNTY Dear Mr. Krizmanich: 1 have completed my geologic investigation, as required by H.B. 1041 and Pitkin County Code §3-80-050, of the above-referenced property on the east side of the Crystal River about 8.5 miles south of Carbondale and just below and south of Wine Point, a ridge above a meander in the Crystal River.The building envelope is in the SE'i4SE'i4 of section 9,T.9 S., R. 88 W., 6th P.M an average elevation of about 6,580 ft, a little southwest of the center of the Mt. So at pris .,., at quadrangle. Geologic Setting, The property lies on mixed and probably interfingering older terrace gravels (Qot) of the Crystal River, alluvial fan materials from the small gullies in the lowest northwest flank of Mt. Sopris to the east, and colluvium (Qc) from the cliffs between the gullies.' The building envelope appears to be a mix of terrace gravel overlain by alluvial fan material underlain by an unknown thickness of similar material to bedrock, which is Maroon Formation of i Pennsylvanian-Permian age. The terrace gravels and alluvial deposits are described by Olander, et al. (1974)as generally poorly-sorted,rounded to angular, unconsolidated rock debris varying in size from clay to boulders. The Maroon Formation bedrock consists ofred arkosic sandstones, siltstones, and mudstones with occasional coarse conglomerate and limestone. The alluvium- bedrock contact is almost certainly less than 100 ft deep and could be less than 50 ft.although near-surface bedrock is not anticipated. Olander, et al., do not map any faulting in the immediate area, although unpublished detailed airphoto mapping by Murray(1966) suggests Isignificant fault control of the Crystal River valley. 4 See Olander,H.C.,Lamm,N.B.,and Florquist,BA, 1974.Roaring Fork and eys,an environmental and engineering geology study.Eagle.Garfield.Gunnison.and Pitkin Counties,Colorado Coloriado Geological Survey Environmental Geology No.8,30 p. 2 Murray.F.N.. 1966,The stratigraphy and structural geology of the Grand Hogback monocine:unpublished PhA.thesis,University of Colorado,219 p. (t (31 -2L'DZ IIIIIIIIIIIIIIIIIIIIIIIIIIIIIII IIIIIIIIIIIIIIIIIIIIIIII 470917 Page: 9 9 of 12 ILVIA DAVIS PITKIN COUNTY CO 08/13/2002 09:33P R 0.00 D 0.00 Page 2 Drainage both above and below the envelope has been significantly altered by construction of subdivision access roads to the south and east and the long-abandoned grade of the Crystal River Railroad to the west. The embankment of the old railroad grade has formed a somewhat boggy I area immediately east of the grade but west and northwest of the envelope,which is located on slightly higher ground. With the exception ofthe Crystal River there are no significant drainages in the area, although two steep gullies immediately east and southeast pose the risk of debris flow, and in fact such flows have occurred in historic time. A similar slightly larger drainage enters the northeast corner of the envelope where it has built a small fan;this drainage,together with rerouted drainage from the previously-mentioned gullies, directly affect the proposed envelope, and overall site drainage will have to be designed and constructed to aggressively protect improvements. Vegetation on the tract has been largely disturbed and consists mostly Of cottonwoods with a few aspen in the low moist area east of the railroad grade, and mature Gambel oak on dryer soils; minor mixed conifers are present throughout. §3-80-050-A. Avalanche Hazard The property lies 600 ft and more from the base of steep slopes of the northwest flank of Mt. Sopris included in an "Area of Potential Avalanches" by the Colorado Geological Survey. There appears to be little risk of snow avalanche reaching the property under any but the most extreme circumstances. The steep cliffs and gullies to the east and northeast of the property present the possibility of debris avalanche. The break in slope between the property and the base of the cliffs together with subdivision and other roads between the envelope and the cliffs substantially mitigate this hazard, although material from debris avalanches could obstruct the small drainages and exacerbate potential debris flows (discussed in part§3-80-050-E below). Avalanche hazard recognition,evaluation,and mitigation I is a highly specialized field that is not my area of expertise, and if a more accurate assessment of the risk and recommendations for mitigation are desired you should seek the opinion of a qualified professional. ` §3-80-050-8 Landslide Hazard The property is not included in an identified landslide area on Pitkin Countyor Co a hazard Colorado Geological Survey geologic hazard maps. Natural slopes � immediately east and northeast of the property are in the 150 to 30a range, are moderately to heavily vegetated, and appear to be stable.The Maroon Formation slopes and cliffs further east and the cliff immediately north range upward from 300 to near-vertical but are not prone landsliding. limited areas of slopes exceeding 15%within the tract'boundary are almost entirely landslide. the result of past construction grading or other previous disturbance and are not subject entirely 3 80 050-C Potentia!/v Unstable Slo rT Hazard Steep slopes well to the east have been discussed. There are no potentially unstable slope hazards on the property ofslopes in excess of 15%within the building envelope can be addressed by onstructionall gr and landscaping. ad ng 3-80-050-D Rockfol►Hazard The property is not included in an identified rockfall hazard area on Pitkin County or Colorado Geological Survey geologic hazard maps. M ost of the property es 600 ft and more from the base of steep slopes of fractured Maroon Formation sand ones There is a slight risk ofrockfall from the cliff immediately north,along the south margi included in an "Area of Rock Falls" by the Colorado Geological Survey (Olander, et al., 1974). n of Wine �L . 131 zoaz IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII 490 of 12 SILVIR DAVIS PITKIN COUNTY CO IIII IIII 13/2002 09.33R R 0.00 0 0.00 Page 3 Point, reaching the envelope. There is an equally small risk in the form of sandstone ledges on the hillside northeast of the envelope. A berm at least four feet high on the upslope side should be incorporated into final landscaping and grading around the north and northeast sides of any structure constructed within 200 ft of the base of the cliff. Depending on building location additional berming,foundation protection,or both may be desirable to protect against rockfall down the slope to the northeast. All berms will have to be carefully coordinated with the mitigating measures for debris flow discussed in§3-80-050-E. Debris flow mitigation will reduce what slight rockfall hazard may exist elsewhere in the evelope. S 340-050-E. Alluvial Fan Hazard The tract is not included in an identified alluvial fan hazard area on Pitkin County and Colorado Geological Survey geologic hazard maps. The property is composed of mixed alluvial materials which probably include the western edges of small alluvial fans formed at the mouths of the minor drainages off the cliffs to the east as discussed previously. A small fan deposited at the bottom of the drainage immediately east of Wine Point constitutes the northeast corner of the building envelope. Debris flows have occurred in these i drainages in historic time, and damage to the subdivision road system has occurred. It is my ■ understanding that flow from the drainages to the east has been diverted north to the vicinity of the small fan at the northeast corner of the property,where it is intended to join flow from that drainage across the proposed envelope and into the Crystal River. Since the location and scope of mitigating measures will depend on building location(s)and design notyet determined, only general recommendations can be made at this point. The current drainage system, both natural and manmade,will have to be determined(snow cover prevents accurate analysis at the time of this writing), and active flows positively directed away from proposed structures with well-defined channels of adequate volume to pass 100-year events corrected for debris-flow characteristics. The extent and nature of additional berms, foundation protection, and other protective measures, if needed,will depend on the location and dimensions of these channels. Alluvial fan,terrace gravel,and colluvial deposits on and beneath the property consist ofwidely- varying sizes of pebbles,cobbles,and boulders in a matrix of sand,silt,and clay.'14VWI erials can be subject to hydrocompaction and may contain voids created by piping, differential compaction,or both;properly-conducted site specific soil testing for foundation design should adequately identify such hazards if present. Since the site is located only a few feet above the Crystal River in an area where drainage has been interrupted by the embankment of the abandoned Crystal River Railroad grade, near-surface groundwater is possible, and soil testing for foundation design should be adequate to establish the absence of near-surface groundwater or to design foundations and other installations accordingly if present. If not existing, establishment of adequate drainage under or through the embankment would be desirable. §3-80-050-F. Talus S►ope Hazard The area is not included in a talus slope hazard area on Pitkin County or Colorado Geological Survey geologic hazard maps. The small strip of talus below the cliff along the southern edge of Wine Point does not appear to affect the envelope. §3,80-050-G. Mancos Shale hazard The area is not included in a Mancos Shale hazard area on Pitkin County or Colorado Geological Survey geologic hazard maps. The Mancos Shale is not present on the surface or in the subsurface at any depth on or in the vicinity of the property. IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII Page: g0900of012 R 0.00 0 0.00 Page 4 $3-80-050-H. Faults hazard. The area is not included in a faults hazard area on Pitkin County or Colorado Geological Survey geologic hazard maps. The property is located along the trace of the Crystal Valley fault system projected by Murray(1966). While there has been no known movement on these faults in historic time and probably none for thousands ofyears,earthquakes of up to Mercalli Intensity VI'have occurred in the region within the last few decades;therefore, new structures should be designed and constructed according to the Uniform Building Code provisions for Seismic Zone 11. §3-80-050-1. Expansive Soil and Rock Hazard. The area is not included in an expansive soil and rock hazard area on Pitkin County or Colorado Geological Survey geologic hazard maps. The possibility of hydrocompactive materials in alluvial, terrace, and clluvial deposits has been discussed. f 3-80-050-1. Ground Subsidence Hazard. The potential for voids created in alluvial,terrace,and clluvial deposits by piping, hydrocompaction, or differential compaction has been discussed, detection of such voids can be accomplished by adequate soil testing, and mitigation can be accomplished if necessary by proper foundation design. There has been no known underground mining in the immediate area of the property, so subsidence due to mining is not anticipated. General. Access to the property is existing in the form of Colorado Highway 133,which parallels the west boundary across the Crystal River, and Crystal River Country Estates subdivision roads. The unconsolidated materials present on the property are derived from a wide variety of rocks, none of which are known to contain significant radioactive minerals in the region, but nevertheless all inhabited spaces should be designed and constructed to prevent the accumulation of radon or other noxious or toxic gases. As always, irrespective of other recommendations contained herein, final grading and landscaping should be designed and constructed in such a manner as to convey water, including snowmelt, away from structures. Water is to be provided by a well, and adequateggund.Water..resources,should be available at +depths, of Iess;,thao 100,ft; depending on the nature of the Maroon Formation beneath the property,groundwater could be high in iron. Waste disposal is by typical septic IDS;the terrace gravels present are adequate for the installation of an IDS,although,particularly since domestic water is to be provided by well, the Pitkin County Sanitation Engineer should be consulted for site-specific recommendations; absence of near-surface groundwater should be established before installation of a septic IDS. Conclusions. The only significant geologic hazard which affects the property as herein defined is in the form of alluvial fan materials possibly mixed with other surficial deposits and the small fans present at the mouths of steep drainages to the east and northeast. Alluvial fans present two distinct classes of hazards,mud-or debris flows and soil problems. Alluvial fans are formed by mud- and/or debris flows, which cascade down the drainage to the break in slope at the bottom,whereupon the flows spread out,the sudden drop in velocity causing the larger,heavier 3 Roughly equivalent to magnitude Son the more-familiar Richter scale. Earthquakes of this magnitude are felt tby all,with damage from minor to moderate. 7 13 ( ^ Zcrp"Z— IIIIII IIIII IIIIII IIIII IIIIII II IIIIIII IIIIII II IIII P470917 age: 112 of O2233R SILVIA DAVIS PITKIN COUNTY CO R 0.00 0 0.00 Page 5 I material in the flow to settle. As new flows occur the coarser materials plug existing channels, forcing the flow in a new direction,eventually producing the fan-shaped deposits that are typical at the base of steep terrain drainages. Debris flows have occurred in the drainages discussed I above, and mitigating measures to protect existing improvements have been installed. Aggressive drainage design and construction will be necessary to assure that these measures are adequate to transport potential flow around or if necessary through the envelope and across the property well away from any structures. In addition, similarly proactive drainage design will be necessary to conduct flow from the gully to the northeast, which empties onto the envelope, across the property. Berming, foundation protection, other protective measures, or some ' combination thereof may be necessary in addition to positive channelization of identified drainages, recommendations for which will be dependent on a detailed analysis of the existing drainage system and at least conceptual building and landscaping location and design. There is a minor rockfall hazard near the base of the Wine Point cliff and the steep slope to the northeast. Incorporation of a berm or wall into final landscaping and grading on the northern and northeastern sides of any structure constructed within 200 ft of the base of the cliff will mitigate this hazard, while the necessity for protection against the slope to the northeast will depend on final building location and landscape design. ' The hazards affecting the property are moderate but with adequate mitigation not significantly 1 different from those affecting many valley-margin sites in Pitkin County previously approved for I development. As a result excavation, foundation, grading, and landscaping design and construction techniques for such locations are well-established. The property is in a geologically- sensitive area, but with mitigation the hazards to which the property is exposed can be minimized;nothing in this report, however,should be construed as suggesting that mitigations recommended herein can or will eliminate such hazards in their entirety. If you have any questions or require any further information, please do not h to to contact me. ` ELF Ff..f55��Nq Sincerely " tE % Bruce A. Ilitig ,5 Consultin', FO Aa0FES51G�n Important Notice:This report concerns natural processes that are unpredictable and in large measure poorly understood. It is intended to identify actual and potential observable hazards to which the subject property is exposed and to suggest mitigating measures in compliance with applicable regulations. Nothing in this report should be construed or interpreted as - suggesting the absence of the described hazards,or that the recommended mitigations will protect the subject property from the described hazards under all circumstances, foreseen or unforeseen. Nothing in this report should be construed or interpreted as suggesting that additional unidentified hazards are not present. It must also be understood that"mitigation" does not mean either the elimination of the hazard(s)or prevention of the consequences of a hazard event or events,only the reduction to the extent reasonably possible of the latter. By accepting this report all present and subsequent parties thereto agree to indemnify and hold harmless the preparer forany and all damages,direct,indirect or consequential,including personal injury or loss of life, above and beyond the original cost of this study,caused by or resulting from any occurrence of the described or other hazard(s),whether or not such damages may result from failure to identify said hazard(s)or from failure or inadequacyofproperly engineered,constructed,and maintained recommended mitigations.The preparer ofthis report cannot and will not be responsible in any way or manner whatsoever for the proper engineering,construction,and/or maintenance of recommended mitigations, or the inadequacy or failure of improperly engineered, constructed, and/or maintained recommended mitigations,or mitigations that have been altered in any way whatsoever from those recommended by the preparer.