Attachment A






AGENDA TITLE: Wind Turbines




Work session to consider possible Zoning Ordinance Amendment to allow wind turbines



STAFF CONTACT(S):  Graham, Fritz, Clark




April 21, 2009


ACTION:      X          INFORMATION:   



 ACTION:              INFORMATION:   








This is the fourth Planning Commission worksession on wind turbines.   As previously noted, it will be very difficult for wind turbines in this area to be cost effective without creating significant visual impacts.   This has made it difficult for staff and the Planning Commission to find an acceptable balance.   At the last worksession, it was agreed that two of the Planning Commissioners would work with staff to develop a proposal that attempts to find this balance point.  This worksession is to review that proposal in advance of a planned County Board worksession on May 6th




Protect the County's Natural, Scenic and Historic Resources

Effectively Manage Growth and Development




The attached outline summarizes a proposed ordinance amendment that would allow wind turbines in the County.  This proposal has limited wind turbines to being allowed to support other uses on the same property.  Effectively, this eliminates commercial/industrial wind turbines that generate power for profit.  


The proposal attempts to balance the County’s interest in promoting sustainable energy with that of protecting its natural resources and vistas.   This is done by a tiered approach very similar to what the Board and Planning Commission have seen with personal wireless antenna.   Tier I are those wind turbines that would have the lowest impact on the community. Tier I facilities are intended to be a simple administrative matter.   Tier II facilities are those that have a higher potential for impacting surrounding properties and/or the community. As such, a Tier II requires the Planning Commission to consider a waiver or modification of the Supplemental Regulations that allow wind turbines.  This process increases the turbine owner’s cost and uncertainty, but attempts to balance their interest against the County’s interest of avoiding undesired impacts.  Tier III facilities are those that are anticipated to result in significant concerns with visual impact. As such, those facilities require a Special Use Permit.   A Special Use Permit will significantly increase the applicant’s cost of obtaining permits and may prove cost prohibitive for some applicants, but this process provides the highest level of County oversight for those uses likely to prove controversial.  




Staff requests the Planning Commission provide comments they would like shared with the County Board with respect to this proposal.     




Attachment A – Wind Turbine Outline


Attachment A


Wind Turbine Outline

10 April 2009 Draft



Small Wind Turbine - A wind energy conversion system used for the generation of power to support an allowed activity on the property.  This includes all components of the system such as the tower, guy wires, wiring, rotors and turbine blades, generators, and control systems.  The small wind turbine may be connected to a public utility and sell power to that utility provided the power sold is not in excess of that typically used for the primary use on that property.    


This definition effectively restricts small wind turbines to an accessory use of the property.  For those turbines that are an accessory to a single family residence or agricultural use, no site plan is required per 18-32.2 of the Zoning Ordinance.  For other uses (e.g. power for a commercial greenhouse), there would still be a site plan requirement to satisfy before a building permit for the small wind turbine could be issued.        


Tier I

A small wind turbine located on property zoned Rural Areas that is not within the Entrance Corridors or the Mountain Contour List as defined in the County’s Comprehensive Plan. 


A Tier I system would be considered a “by right” use, subject to the conditions in the Supplementary Regulations of the Zoning Ordinance but administratively handled with minimal cost to applicants.  These facilities are anticipated to result in very little or no impact to the community and would have minimal costs associated with County requirements.     


Tier II

A small wind turbine that does not qualify as a Tier I, but still fits conforms to the height restrictions in the underlying zoning district.  This would include situations such as a system within the Entrance Corridor, reduced setbacks, or located within the Development Areas.   


This would require the Planning Commission waiving a condition of the Supplemental Regulations.   The administrative cost for such a system would be considerably higher than a Tier I but less than the Special Use Permit required for a Tier III.


Tier III

A small wind turbine that does not conform to the height restrictions of the underlying zoning district.  


This system would require a Special Use Permit in order to be permitted.  



Supplemental Regulations for Small Wind Turbines

Within Section 5 of the Zoning Ordinance (Supplementary Regulations), establish conditions for wind turbines.  As a Supplementary Regulation, the Planning Commission may waive or modify these conditions, for a Tier II facility.   This provides the simplest oversight for situations where project specific conditions may require special consideration.   The following are the recommended conditions:     


1.                    Small wind turbines are an allowed use within the Rural Areas Zoning District. 

This makes wind turbines a “by right” use within the RA zoning district and allows the Planning Commission to decide if the use is appropriately sited in other zoning districts where the potential for conflicts between uses are higher.      


2.                    Require a minimum setback from property lines of the height of the structure, plus twenty feet.  It is recommended this include a provision for an administrative waiver where the applicant has demonstrated to the satisfaction of the Agent and County Attorney that the adjoining property owner has agreed to restrict development within that part of their property that would be within this setback distance.  

This allows a margin of safety for structure collapse and ice throws from turbines.


3.                    Prohibit collocation of personal wireless service antenna

This avoids situations where wind turbines might be constructed to circumvent wireless facility ordinance requirements rather than being primarily intended for generation of wind energy.


4.                    Prohibit all lighting of the wind turbine and tower. 

This restriction recognizes the dark skies provisions in the Comprehensive Plan.  


5.                    Prohibit wind turbines within the Entrance Corridor Overlay District or within the Mountain Contour List as defined by the Comprehensive Plan .  This assures oversight by the Planning Commission for visual impacts within the Entrance Corridors and mountains.  Within the EC, the Planning Commission may also request input from the Architectural Review Board before considering a request. 


Height Restrictions  

Under Section 4.10 of the Zoning Ordinance, add a provision for small wind turbines to meet the height limits within the underlying zoning district, but allow this to be modified by Special Use Permit. Application requirements for this Special Use Permit would be similar to those for personal wireless towers. 


This would require those wind turbines that will have the highest potential impacts to be considered as a Special Use Permit where conditions could be used to mitigate impacts.   For example, this could consider locations that minimize skylighting, colors for the wind turbine, or sensitivity to bird migration paths.       




A building permit is required prior to the County permitting construction of a small wind turbine.   A site plan may be required before a building permit application is submitted  per 18-32.2 of the Zoning Ordinance for those uses that are not exempted from the site plan requirements.  .  The following information must be provided with the building permit application. 

1.                   A plat of the property that clearly shows the boundary lines, location of the proposed small wind turbine, and setbacks to the property line.  

2.                   Plans that clearly show the total height of the proposed structure and satisfy all provisions of the Building Code.

3.                   A signed and notarized affidavit using a County form that demonstrates the small wind turbine will be used to support an allowed use of the property and assures the small wind turbine shall be removed if the supported use is ended.      


Tier I - 

A Tier I small wind turbine is a “by right” use and will typically only require a building permit.         


Recognizing administrative costs can be a significant deterrent to use of small wind turbines, this provision attempts to keep that cost to a minimum.  


Tier II - 

A Tier II small wind turbine shall require Planning Commission approval of a waiver or modification of the conditions in the Supplemental Regulations prior to approval of a building permit or site plan.  As part of approving a waiver or modification, the Planning Commission may establish reasonable conditions to assure the  ordinance intent is maintained.   If the commission denies an application, it shall identify which requirements were not satisfied and inform the applicant what needs to be done to satisfy each requirement. 


Recognizing site specific considerations may suggest a small wind turbine should be allowed, the Planning Commission can waive or modify the requirements as related to setbacks, zoning districts and overlay districts, collocation of antenna,  and lighting.  Depending on the submission requirements, the cost of this application may be a significant deterrent to applicants constructing small wind turbines.    


Tier III

A Tier III small wind turbine shall require Board of Supervisors approval of a Special Use Permit prior to submission of a building permit or site plan.


This provision is used for those turbines that present the most significant visual impact.  Anticipating submission requirements similar to those used for personal wireless facilities, the cost of this application is anticipated to be a significant deterrent to applicants constructing small wind turbines.  It is anticipated the County will see very few of these applications.    


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