§ 20.10A.040. Design standards.

The following standards are established as the minimum necessary to ensure that the purpose of this rural residential, one dwelling unit per two acre district is achieved and maintained as new lots are created and new buildings are constructed:

1.

Minimum lot size:

a.

Conventional subdivision lot (net)—one and one-half acres for single-family, three acres for duplexes;

b.

Cluster subdivision lot—one acre for single-family, two acres for duplexes, subject to applicable standards for provision of water and sewage disposal contained in Articles III and IV of the Thurston County Sanitary Code; and

c.

Nonresidential use—two acres.

2.

Maximum building height—thirty-five feet.

3.

Minimum yard requirements: See Section 20.07.030.

4.

Maximum Coverage by Hard Surfaces. Maximum hard surface coverage for new development in this district is as follows (also see Chapter 20.07):

a.

Within the Green Cove Creek Drainage Basin:

i.

Lots less than four acres forty-five percent or ten thousand square feet, whichever is less;

ii.

Lots four acres or more—six percent.

Where only a portion of a parcel is located within the basin, the impervious surface limits are applied to that portion of the parcel only. For example, if two acres of a five-acre parcel lie within the basin, then up to six percent of the two-acre portion may be covered with impervious surfaces.

For all other development: Sixty percent or twenty-thousand square feet, whichever is less.

5.

Vegetation Retention Within the Green Cove Creek Drainage Basin.

a.

Tree Tracts. Subdivisions, short subdivisions, large lot subdivisions, and other developments within the basin, except construction of dwellings on individual lots/parcels, shall retain at least sixty percent of the site within tree tracts held in common ownership by the homeowner's association or comparable entity. For purposes of this section, a tree tract is a lot or area of land dedicated to tree retention for purposes of absorbing stormwater runoff. A tree tract may be included in a resource use parcel created as part of a planned rural residential development. However, there shall be no harvesting of trees from the tree tract. The tree tract(s) should be located downslope of the developed portion of the site, unless otherwise determined by the approval authority. Passive recreational uses, such as picnic areas and trails, which would not jeopardize the survival of protected trees (e.g. by damaging roots, compacting soil, or altering drainage), can be located in tree tracts with written approval of the department. The department may also authorize stormwater ponds in tree tracts if trees would not be removed and tree roots would not be damaged during construction or by saturated soil conditions such that their survival would be jeopardized. Prior to acting on the request, the approval authority may require the proponent to supply a written analysis from a qualified professional forester regarding the proposal's potential impact on the protected trees.

b.

Existing stands of healthy trees on the site shall be included within the tracts required by subsection (5)(a) of this section to the greatest extent practical, as determined by the approval authority. Where tree tracts are required and where a site does not contain healthy trees that can be incorporated in the project and remain windfirm following development, the tree tract shall be planted with trees. Trees to be planted shall be of a type and spacing that, upon maturity, will provide a canopy spanning at least seventy-five percent of the tract. At the time of planting, evergreen trees shall be at least four feet tall and deciduous trees shall be at least one and one-half-inch caliper. New plantings shall consist of tree species native to the area.

c.

A bond or other such method of financial security in an amount equal to one hundred twenty-five percent of the cost to purchase and install the required trees, based upon a contractors estimate accepted by the county, shall be provided to the county to secure the successful establishment of newly planted trees. The county shall draw upon this surety as needed to replace any trees that die, upon failure of the developer or other responsible party to do so within the time period specified by the county. The developer shall not be required to replant trees which die or suffer severe degradation as a result of a water purveyor's failure to supply adequate water, acts of vandalism or other actions of unrelated third parties acting beyond the developer's control. Such financial security shall be effective for a two-year period following completion of the planting.

d.

Critical areas and associated buffers may comprise all or part of the tree tracts/vegetation protection areas required by subsection (5)(a) of this section.

e.

Where conflicts occur between the provisions of Chapter 17.25 or Chapter 18.47 and this section, the provisions of this section shall prevail.

(Ord. 13834 § 5, 2007)

(Ord. No. 14524, § 3, 6-7-2011; Ord. No. 14773, § 10(Att. I), 7-24-2012; Ord. No. 15355, 1(Att. A, § W), 10-18-2016)