§ 20.09A.050. Design standards.

The following standards are established to insure that the purpose of this district is achieved and maintained as new lots are created and new buildings are constructed:

1.

Subdivision Alternatives. Land within this district may only be divided as follows:

a.

Large lot subdivisions, or

b.

Subdivisions or short subdivisions in conformance with Chapter 20.30A, Planned Rural Residential Development;

2.

Minimum Lot Size. The minimum lot sizes in this district are as follows:

a.

Large lot—five acres or one-one hundred twenty-eighth of a section,

b.

Planned rural residential developments—none, 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.

Special uses for which a minimum lot size is not established by Chapter 20.54—Five acres, with the exception of fire district facilities which may be located on lots of less than five acres.

3.

Maximum Building Coverage. Building coverage for fire district facilities and expansion at existing academic schools (as defined in 20.03.040 TCC) shall be specified through the special use permit process and/or SEPA environmental review process as applicable. For all other special uses with no maximum building coverage specified in Chapter 20.54 TCC, the maximum building coverage shall be six thousand square feet for parcels five to ten acres in size and twenty thousand square feet for parcels over ten acres in size.

4.

Maximum Building Height. Buildings shall not exceed a height of thirty-five feet, except for structures exempted from this height requirement pursuant to Section 20.07.080.

5.

Minimum Yard and Setback Requirements. See Chapter 20.07.030.

6.

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 hard 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 ten thousand square feet of the two-acre portion may be covered with hard surfaces. The provisions of the Drainage Design and Erosion Control Manual (Chapter 15.05 TCC) may further limit the amount of hard surfaces.

b.

For all other subdivisions, large lot subdivisions, short plats and new construction:

i.

Lots two and one-half acres or greater: Ten percent.

ii.

Lots less than two and one-half acres: Sixty percent or ten thousand square feet, whichever is less.

7.

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.

New construction of dwellings on lots five or more acres in size, except those served by a tree tract created under subsection (6)(a) of this section, shall retain existing vegetation on sixty percent of each lot. Vegetation in these areas shall be preserved, with the exception of nonnative, invasive plants and hazard trees that pose an imminent risk of damaging a structure, as determined by the approval authority. Authorized removal of vegetation from the protected portion of the site shall be accomplished by the least disruptive methods available, as determined by the approval authority.

c.

Existing stands of healthy trees on the site shall be included within the tracts/vegetation protection areas required by subsections (6)(a) and (b) 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.

d.

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 contractor's 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.

e.

Critical areas and associated buffers may comprise all or part of the tree tracts/vegetation protection areas required by subsections (6)(a) and (b) of this section.

f.

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. 13884 § 9, 2007; Ord. 13235 § 6, 2004; Ord. 11398 § 3 (part), 1997: Ord. 10398 § 7 (part), 1993)

(Ord. No. 14377, § 1, 7-6-2010; Ord. No. 14773, § 10(Att. I), 7-24-2012; Ord. No. 15204, § 1, 10-27-2015; Ord. No. 15355, 1(Att. A, § S), 10-18-2016)