A. Base Density: The maximum base density of a CD for land regulated by title 9, chapters 5, 5A, 6, and 6A of this code, shall be the base density of the underlying zoning district. Base density is calculated on the size of the parent tract.
B. Density Bonus: One primary residential dwelling unit (and any employee housing as otherwise permitted) on the conservation tract of a CD in addition to the base density. This density bonus shall be permitted within any parent tract one time from the date of the adoption of this chapter.
C. Minimum Lot Size, Dimensions, And Setbacks: Lot sizes for residential development proposed within the cluster tract may be modified from the minimum lot size required in the underlying zoning district provided that on site sewage disposal requirements of South Central district health department and other design standards are met through the design of the CD. Lot dimensions and setbacks may be modified from that required in the underlying zoning district provided the modification facilitates the purposes of a CD. The minimum lot size in a CD located in a TDR receiving area shall be one acre.
D. Standards For Multiple Cluster Tracts: Residential lots within a CD shall be located in one or more cluster tracts. The board may require building envelopes on lots, which shall comply with the following standards:
1. General Site Design Standard: In general, the layout of cluster tracts shall promote the rural character of the zoning district, avoid the creation of new rural towns or villages, support the viability of existing or future agricultural activities on or adjacent to the site, and protect natural, historic, cultural and scenic resources on or adjacent to the site. The siting standards in this section are in addition to and complement the standards of evaluation in section 10-9-8 of this chapter.
2. Siting Criteria For Cluster Tracts: Cluster tracts shall be located within one mile of a paved state, federal, or county road or a paved road constructed to county standards in existence as of July 5, 2006.
3. Maximum Number Of Lots Per Cluster Tract: Within a CD, the maximum number of lots allowed in a single cluster tract shall be five (5) lots unless the CD meets the standards listed in subsection D4 of this section.
4. Allowance For Larger Clusters: Cluster tracts of up to twenty (20) lots may be allowed in the A-20, A-40, R-10, or RR-40 districts if located on property within one-half (1/2) mile of an unincorporated platted townsite (i.e., Picabo, Gannett), and the cluster tract(s) is located to the maximum extent practicable as an extension of the townsite. Larger cluster tracts up to twenty (20) lots may also be located in other areas where the applicant can demonstrate that the cluster tract(s) meets the following standards:
a. Promotes the rural character of the zoning district;
b. Avoids interference with existing agricultural activities on or adjacent to the parent tract;
c. Protects and enhances natural resources, including wildlife, wetlands and riparian areas, native vegetative resources, and historic or cultural resources on or adjacent to the parent tract;
d. To the maximum extent practicable, preserves significant views of the rural, open character of the district as viewed from the paved road;
e. Provides a minimum setback of one hundred feet (100') from adjacent properties;
f. Provides a minimum setback of two hundred feet (200') from existing agricultural activities;
g. Avoids fragmentation of the conservation tract; and
h. Provides contiguity between the conservation tract and open space on adjacent properties.
5. Minimum Separation Required: To avoid the creation of rural villages and to maintain the open, rural character of the zoning districts, multiple cluster tracts shall be noncontiguous, according to the following standards:
a. If the total land area within the CD parent tract is more than three hundred twenty (320) acres, a cluster tract shall be separated from all other cluster tracts by at least one thousand eight hundred feet (1,800').
b. If the total land area within the CD parent tract is three hundred twenty (320) acres or less, a cluster tract shall be separated from all other cluster tracts by at least one thousand feet (1,000').
c. Separation of multiple cluster tracts is required regardless of whether the clusters are located within the same CD or in a different CD.
d. For purposes of this subsection, separation between cluster tracts shall be measured as the shortest linear distance between the two (2) closest building envelopes located in the different cluster tracts.
6. Exception To The Minimum Separation Requirement: The minimum separation requirement in subsection D5 of this section may be reduced if the smaller separation satisfies the general and specific site design standards and criteria in subsections D1 and D3 of this section, and that either:
a. The overall site design takes advantage of the site's natural topography to hide multiple clusters from the public's view as seen from a paved road; or
b. The smaller separation is necessary to accommodate conservation of natural resources; or
c. The smaller separation is necessary and desirable to support continuation of existing agricultural operations or creation of new agricultural operations.
In no case shall the separation between cluster tracts be less than four hundred feet (400').
7. Pedestrian And Maintenance Access:
a. Maintenance, pedestrian, and equestrian access easements may be required through the conservation tract with a minimum access easement of thirty feet (30').
b. Access may be restricted to agricultural lands for public safety reasons and to prevent interference with agricultural operations; access to areas of steep slopes, wetlands, critical wildlife habitat or other sensitive areas may also be restricted.
8. Review Criteria: The board may approve a cluster application upon findings that the proposed cluster subdivision plat complies with the Blaine County comprehensive plan and with the standards set forth in this chapter, except where the board expressly permits exceptions and variances to such standards.
a. The board retains the discretion to deny a rural cluster application if it finds the location of the cluster(s) will have a negative impact upon service delivery, or the subject property uniformly exhibits such extraordinary natural and environmental value, as evidenced by the proposed location of the rural cluster in the following districts as described in title 9, chapters 17, 19, 20, 21, 21A, 22 and 23 of this code. These include the county's wildlife, wetlands, floodplain and riparian districts, mountain, scenic highway, avalanche, and seasonal use overlay districts.
b. The board also retains the discretion to approve the proposed cluster subdivision conditioned on the applicant agreeing to a reduced residential density if the board finds that such condition would mitigate potential adverse impacts related to the requested density. (Ord. 2006-07, 6-29-2006)