Chapter 9
GREEN COVE BASIN

Chapter 9

9.010    General

9.020    Streets

9.030    Driveways

9.040    Sidewalks

9.050    Parking Lots

9.060    Stormwater

9.010 General

The development standards and Standard Drawings in Chapter 9 provide street and stormwater designs required in the Green Cove Basin. The Green Cove Basin roughly aligns with the Rural Low Impact (RLI) Zone in the northwest part of the City. However, to confirm whether these standards are applicable to a project, contact the Public Works Department.

Design guidelines and standards not addressed in Chapter 9 are provided in Chapters 1 through 8 of the Engineering Design and Development Standards.

9.020 Streets

A.    Streets and Alleys: Residential blocks bounded by streets will not exceed a walking perimeter of 1,700 feet. Commercial blocks will not exceed a walking perimeter of 2,200 feet. Where larger blocks are necessary due to topography, existing development, or other constraints, intervening public cross-block pedestrian, bicycle, and emergency access will be provided.

B.    Surfacing, Permeable Pavement: Permeable pavement materials may be permitted or required at the discretion of the Director of Public Works.

9.030 Driveways

Permeable pavement materials may be permitted or required in place of cement concrete at the discretion of the Public Works Director.

9.040 Sidewalks

Sidewalks will be 4 inches thick and constructed of pervious concrete meeting the requirements of Appendix 5 of Chapter 4. Impermeable Portland Cement concrete sidewalks may be approved for a project, if site conditions limit or prohibit the use of pervious concrete. A deviation request for the use of impermeable concrete shall be submitted to the City Engineer, per section 1.050 of the EDDS. When the sidewalk and curb are contiguous, the width of the sidewalk will be measured from face of curb to back of sidewalk. Curbs integral or permeable sidewalks are not allowed.

Asphalt sidewalks will not be permitted unless otherwise approved by the Public Works Director.

9.050 Parking Lots

A parking lot construction permit is required prior to surfacing any unsurfaced designated parking area.

Stormwater retention will be provided and will follow the criteria as set forth in Chapter 5 of these Standards.

Number of plans and specifications will be as required by the Community Planning and Development Department and be submitted for review and approval by the City with respect to stormwater discharge and on-site retention or detention, matching street and/or sidewalk grades, access locations, parking layout, and to check for future street improvement conformity and City zoning regulations.

Parking lot surfacing materials will be permeable and satisfy the requirement for a permanent all-weather surface. Traditional impervious asphalt concrete pavement and cement concrete pavement do not satisfy this requirement. Gravel surfaces are not acceptable or approved surface material types. Combination grass/paving systems are approved surface material types; however, their use requires submittal of an overall parking lot paving plan showing the limits of the grass/paving systems and a description of how the systems will be maintained. If the City determines the grass/paving system is not appropriate for the specific application, alternate permeable surfacing materials will be utilized.

9.060 Stormwater

All developments shall be designed to comply with all applicable core requirements in Olympia’s 2016 Drainage Design and Erosion Control Manual.