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HomeMy WebLinkAboutbocc.ord.019.2000 ORDINANCE OF THE BOARD OF COUNTY COMMISSIONERS OF PITKIN COUNTY, COLORADO,AMENDING SECTION 3-80-50,GEOLOGIC HAZARD AREAS OF THE PITKIN COUNTY LAND USE CODE Ordinance No.�U/ -2000 RECITALS 1. Pitkin County Open Space and Trails("Applicant")requested that the Board of County Commissioners of Pitkin County,Colorado("BOCC")consider an amendment to Section 3-80-050 of the Land Use Code("Code"), Geologic Hazard Areas,to allow construction of trails within geologic hazard areas. 2. The Pitkin County Planning and Zoning Commission considered the proposed code amendment at a regularly scheduled meeting on March 14, 2000,and recommended approval by a vote of 3-0. 3. The BOCC considered the proposed code amendment at a duly noticed public hearing on April 12, 2000,and voted to approve the proposed amendment on first reading. 4. The BOCC adopted the proposed amendment on second reading on April 26,2000. 5. The BOCC finds that the proposed code amendment accommodates access to public lands,which is consistent with land use policy 2-290 in the Code. 6. The BOCC further finds that the proposed code amendment is consistent with the applicable provisions of the Code. NOW,THEREFORE,BE IT ORDAINED by the BOCC that it hereby amends Title II of the Pitkin County Code,the Land Use Code,as follows in Attachments A. NOTICE OF PUBLIC HEARING published in the Aspen Times Weekly on the 1 st day of April, 2000. INTRODUCED AND FIRST READ AT A PUBLIC HEARING on the 12th day of April, 2000. APPROVED AND ADOPTED AFTER SECOND READING on the 26th day of April,2000. PUBLISHED AFTER ADOPTION in the Aspen Times Weekly on the day of �,2000. p; oiQ-zoao THIS ORDINANCE SHALL BECOME EFFECTIVE 30 DAYS AFTER PUBLICATION FOLLOWING FINAL ADOPTION BY THE BOARD OF COUNTY COMMISSIONERS. BOARD OF COUNTY COMMISSIONERS OF PITKIN COUNTY,COLORADO By LAA�� 17 --- ATTEST: Shellie Roy Harper, hair (�, -' A't"Oowf — �dey&.'Dean, Date Clerk to the BOCC (/APPROVED AS TO FORM: APPROVED AS TO CONTENT: ounxtAttornCey Cindy Houben, CA u A �S oti Community Development Director D ; 0 14 -2Coo ATTACHMENT A REPEAL AND REENACT SECTION 3-80-050 AS FOLLOWS: SUBSECTION 3-80-050 GEOLOGIC HAZARD AREAS This section identifies development standards applicable to specific geologic hazard areas in addition to the general standards in Section 3-80.30. A. Avalanche Areas 1. High Hazard Avalanche Zone: Development is prohibited within High Hazard Avalanche zones. In the event that there is no High Hazard-free area on a site and a development application is subsequently denied, an applicant may appeal the denial to the Board of County Commissioners pursuant to Section 3-290 of this Code. If an appeal of a project denial is granted by the Board, then the development application shall incorporate hazard mitigation according to the standards in Part 3 of this section. 2. Moderate Hazard Avalanche Zone: Development within a Moderate Hazard Avalanche Zone may only be permitted under the following circumstances: a. If an entire property is affected by the Moderate Hazard Avalanche Zone, development may be permitted if the hazard can be adequately mitigated to insure public safety pursuant to the standards in Part 3 of this section. b. In the event that development outside of the Moderate Hazard Avalanche Zone will result in significant environmental degradation, the Board may, in its discretion, approve such development with adequate mitigation measures to assure the safety of the occupants of the property. C. If the Board finds that other hazards present on a property outweigh the risks associated with development in the Moderate Hazard Avalanche Zone, the Board may, in its discretion, grant approval to such project subject to compliance with the mitigation measures specified in Part 3 of this section. d. If a development project located within the Moderate Hazard Avalanche Zone is denied, an applicant may appeal the denial to the Board of County Commissioners pursuant to Section 3-290 of this Code. If an appeal of a project denial is granted by the Board, then the development application shall incorporate avalanche hazard mitigation pursuant to Part 3 of this section. 3. Mitigation Standards a. Development shall be restricted to the least hazardous area of a project site. b. If structural avalanche defenses are required to protect people or structures, they shall be designed by a certified engineer to withstand avalanche impact forces. C. Clear-cutting or other large scale removal of vegetation, particularly within avalanche path starting zones, shall be prohibited. d. Extractive operations are prohibited within avalanche hazard zones during the winter unless there is an approved program of avalanche control and defense measures. Attachment D—Page 1 �'. 019-1cco e. Utility lines or pipes crossing hazard zones shall be buried. Surface pipes, poles, or towers for suspended transmission lines in hazard zones shall be protected by utilizing avalanche diversion methods or protection structures. f. Roads intended for winter use shall avoid avalanche hazard areas. If the Board finds that it is not possible to construct a road that avoids high or moderate avalanche hazard areas, then the Board may approve a road subject to site specific mitigation methods. Roads which must cross hazardous areas shall be designed to limit exposure and utilize avalanche control practices to reduce the danger along exposed road segments. Where the main access road to a proposed development is crossed by an avalanche path, a secondary access may be required. g. Warning signs shall be placed along commonly traveled winter roads and trails which cross avalanche hazard zones. h. Property owners who develop in avalanche areas or obtain driveway access through avalanche areas shall bear the costs of any avalanche control measures that may be required to mitigate the hazard. B. Landslide Areas: Development is prohibited within Landslide Areas. In the event that there is no hazard-free area on a site and a development application is subsequently denied, an applicant may appeal the denial to the Board of County Commissioners pursuant to Section 3-290 of this Code. If an appeal is granted by the Board and development is permitted, an application shall be reviewed according to the following standards: 1. Insure strict adherence to recommended design, construction and maintenance procedures approved by qualified professional geologists or engineers; 2. Avoid adding water to the site that would cause decreased stability; 3. Avoid removing the toe of the slide without adequate mechanical support; 4. Avoid increasing the weight load on the top of the slide; 5. Avoid removing vegetation from the site; and 6. Avoid steepening the existing slope of the slide area. C. Potentially Unstable Slopes 1. Development is prohibited on slopes greater than fifteen percent(15%) unless a specific development proposal is found to result in a site design that creates less impact than if the development was limited exclusively to slopes of less than fifteen percent(15%). In the event that a development proposal utilizes slopes in excess of fifteen percent (15%) or if a development site is comprised exclusively of slopes which exceed fifteen percent(15%), design and development shall be based on a detailed site analysis, including geologic and engineering studies to identify the best development area based on the following considerations: a. Adequate mechanical support shall be provided for cut slopes. b. Adding water which may decrease slope stability shall be avoided. C. Adding weight to the top of the slope shall be avoided. d. Disturbed slopes must be contoured so that they can be revegetated. Attachment D—Page 2 o : ait? --C100 e. Steepening of existing slopes shall be avoided. f. Confine cuts, fills, grading and excavation to the minimum area needed for construction. 2. Development is prohibited on slopes greater than thirty percent(30%) , except as permitted herein. a. Exception for Minor Changes in Slope-Development may be permitted on lands that have a slope in excess of thirty percent (30%) when the slope is due to the presence of a minor natural or man- made change in the gradient of a continuous slope, provide the following conditions are met: 1. Not Subject to Instability-The applicate demonstrates that the slope's ground surface are not prone to instability or failure and that the proposed development will not cause greater instability or increase the potential for slope failure. 2. Compliance with Other Regulations-The applicant demonstrates that development on slopes in excess of thirty percent(30%) does not increase visual, wildlife or wildlife impacts, or compromise or conflict with other policies or standards of the Land Use Code. In the event that there is no area on a site with slopes less than thirty percent(30%), and/or the development proposed does not comply with the criteria of Section 3-80.50(C)(2)(a) as determind by the Community Development Director, and a development application is subequently denied, an applicant may petition the Board of County Commissioners for consideration pursuant to Section 3-290 of this Code. If an appeal is granted by the Board and the development is permitted, an application shall be reviewed according to the criteria in section 3-80.50(C)(1). D. Rockfall Areas 1. Development is prohibited within Rockfall Areas. In the event that there is no hazard-free area on a site and a development application is subsequently denied, an applicant may petition the Board of County Commissioners for consideration pursuant to Section 3-290 of this Code. If an appeal is granted by the Board and development is permitted, an application shall be reviewed according to the following standards: a. Only be permitted if design and construction stabilization and maintenance measures approved by a qualified professional geologist or engineer and the County are utilized. Construction stabilization measures may include but are not limited to: 1) Stabilization of rocks by bolting, gunite application (cementing), removal of unstable rocks (scaling),.cribbing or installation of retaining walls; 2) Slowing or diverting the moving rocks by rock fences, screening, channeling and dams, or by concrete barriers or covered galleries; 3) Physical barriers around vulnerable structures; and 4) Periodic maintenance of mitigation measures. b. Not increase water supply to cliffs or overhangs. C. Not remove protective vegetation. d. Not add weight or otherwise disturb overhanging strata. Attachment D—Page 3 Q : e�9 -Za0o e. Not make any excavations that remove underlying support. f. Not increase erosion that removes underlying support. E. Alluvial fans 1. In the event there is not an adequate hazard-free area on a site, land uses may: a. Be based upon a site evaluation and recommendations of a qualified professional engineer or geologist; and b. Be protected by channelizing, damming or diverting potential mud or debris flows utilizing engineering structures by a qualified professional engineer or geologist. 2. Prohibit disturbance in the drainage basin above the fan unless an evaluation of the effect on runoff and stability of the fan shows that disturbance is acceptable. F. Talus Slope 1. In the event there is not an adequate hazard-free area on a site, permit structural construction associated with residential, commercial, industrial and high impact recreational activity only if design and construction stabilization and maintenance measures approved by a qualified professional geologist or engineer and the County are utilized. 2. Design developments to withstand downslope movement. 3. Bury foundations and utilities in talus slope areas below the active surface. 4. Minimize site disturbance in talus slope areas to avoid inducing slope instability. 5. Do not remove the toe of a talus slope without providing adequate mechanical support. G. Mancos Shale: Development within a mancos shale area may be permitted: 1. If design and construction stabilization and maintenance measures approved by a qualified professional geologist or engineer and the County are utilized; 2. Based upon an evaluation of the development's effect on slope stability and shrink-swell properties; 3. If designed to provide adequate surface drainage; and 4. Concentrated runoff from impervious surfaces into natural drainages shall be prohibited unless it is demonstrated that there will be no adverse effects. H. Faults: In the event there is not a hazard-free area on the site, land uses may incorporate adequate mitigation measures determined by a qualified professional engineer or geologist and approved by the County. I. Expansive Soil and Rock: Permit development in an identified area of expansive soil and rock upon County approval of engineered foundations and floor systems designs. J. Ground Subsidence: In the event a development site is comprised exclusively of moderate and extremely hazardous areas, permit development if design and construction stabilization and Attachment D-Page 4 Ot 4'ZoO� maintenance measures approved by a qualified professional geologist or engineer and the County are utilized. (Prior code§ 3-805)(97-30, Amended, 07/23/1997) K. Exceptions 1. Construction of non-motorized, public trails on land owned or held in easement by a public or non-profit agency shall be subject to 1041 review, but shall be exempt from the standards for development in geologic hazard areas, provided that such trails shall be subject to any other applicable regulations of this Code and the following provisions: a. No non-motorized, public trail shall be permitted in a geologic hazard area, which would subject occupants or users of the area to hazardous conditions; create or worsen such conditions affecting other developments, activities and lands; subject other persons or the County to dangers or expenses required to mitigate such hazardous conditions, respond to emergencies created by such conditions or rehabilitate the improvements, activities and lands. b. A non-motorized, public trail in a geologic hazard area shall be constructed in such a manner as to mitigate the hazard to public health and safety or to property due to geologic hazards. C. Nordic trails shall avoid avalanche hazard areas. Attachment D—Page 5