18.01.070 Performance standards.
The following general performance standards shall apply to activities permitted with in critical areas or critical area buffers. Additional standards may be necessary based on site specific considerations or proposed development impacts.
A. General Performance Standards.
1. Areas of new permanent disturbance and all areas of temporary disturbance shall be mitigated and/or restored pursuant to a mitigation and restoration plan based off of Wetland Mitigation in Washington State, Part 1: Agency Policies and Guidance (Version 1, Publication #06-06-011a, March 2006, or as amended) and Wetland Mitigation in Washington State, Part 2: Developing Mitigation Plans (Version 1, Publication #06-06-011b, March 2006, or as amended).
2. Mitigation plans shall include a discussion of mitigation alternatives (sequencing) as they relate to:
a. Avoiding the impact altogether by not taking a certain action or parts of an action;
b. Minimizing impacts by limiting the degree or magnitude of the actions and its implementation, by using appropriate technology, or by taking affirmative steps to avoid or reduce impacts;
c. Rectifying the impact by repairing, rehabilitating, or restoring the affected environment;
d. Reducing or eliminating the impact over time by preservation and maintenance operations during the life of the action;
e. Compensating for the impact by replacing, enhancing, or providing substitute resources or environments; and/or
f. Monitoring the impact and taking appropriate corrective measures.
3. All boundaries of critical areas or any associated buffers shall be delineated prior to development activity on site.
4. Mitigation Ratios shall mean those wetland mitigation ratios as shown on attached Table 18.01-2.
|
Category and Type of Wetland |
Creation or |
Rehabilitation |
Enhancement |
Preservation |
|---|---|---|---|---|
|
Category I: Bog, Natural Heritage Site |
Not considered possible |
6:1 |
Case-by-case |
10:1 |
|
Category I: Mature Forested |
6:1 |
12:1 |
24:1 |
24:1 |
|
Category I: Based on functions |
4:1 |
8:1 |
16:1 |
20:1 |
|
Category II |
3:1 |
6:1 |
12:1 |
20:1 |
|
Category III |
2:1 |
4:1 |
8:1 |
15:1 |
|
Category IV |
1.5:1 |
3:1 |
6:1 |
10:1 |
B. Wetland Areas.
1. Lights shall be directed away from the wetland.
2. Activities that generate noise shall be located away from the wetland, or noise impacts shall be minimized through design or insulation techniques.
3. Toxic runoff from new impervious surface area shall be directed away from wetlands.
4. Treated storm water runoff may be allowed into vegetated wetland buffers in accordance with provisions of the Eastern Washington Stormwater Manual. Channelized flow shall be prohibited.
5. Use of pesticides, insecticides and fertilizers within 150 feet of wetland boundary shall be limited and follow Best Management Practices (BMPs).
6. The outer edge of the wetland buffer shall be marked, identified, planted with dense native vegetation and/or fenced with wildlife permeable fencing for the purposes of identifying the wetland buffer area and to discourage human disturbance.
C. Critical Aquifer Recharge Areas (CARA).
1. The city lies over alluvial soil deposits. There are unconsolidated materials composed of silt, sand and gravel, which in places are several hundred feet in depth. This deposit material is important as a water conveying unit and supplies the groundwater of stream flow (recharge). In general, areas of permeable soils in combination with geological transfer structure may be aquifer recharge areas. Based on the information and maps contained in hydrology of the Upper Yakima River Basin and landscape planning, environmental applications, the city is as an aquifer recharge area. This is a preliminary determination until further studies of geology and hydrology are conducted on an overall or individual property specific basis to either include or exclude them as an aquifer recharge area
2. All structures shall be placed to provide a maximum buffer to known specific CARA.
3. Impervious coverage of the lot shall be minimized.
4. Best Management Practices shall be used during construction.
D. Fish and Wildlife Habitat Conservation Areas.
1. Flora (plant life) and Fauna (animal life) identified as protected, shall be sheltered from construction activities using Best Management Practices.
2. Replacement of any flora shall be maintained by the applicant for three years to establish viable plant life.
E. Frequently Flooded Areas.
1. All structures and other improvements shall be located on the buildable portion of the site out of the area of flood hazard. Where necessary residential buildings may be elevated.
2. Utilities shall either be located three or more feet above the base flood elevation (BFE), or be engineered to the City of Cle Elum Engineers requirements appropriate for the conditions.
3. All new construction and substantial improvements shall be constructed using flood resistant materials and using methods and practices that minimize flood damage.
4. All new construction and substantial improvements shall be anchored to prevent flotation, collapse, or lateral movement of the structure.
5. No rise in the BFE shall be allowed. Post and piling techniques are preferred and are presumed to produce no increase in the BFE.
6. Modification of stream channels shall be avoided.
F. Geologically Hazardous Areas.
1. Structures and improvements shall minimize alterations to the natural contour of the slope, and foundations shall be tiered where possible to conform to existing topography.
2. Structures and improvements shall be located to preserve the most critical portion of the site and its natural landforms and vegetation.
3. The proposed development shall not result in greater risk or a need for increased buffers on neighboring properties.
4. Development shall be designed to minimize impervious surfaces within the critical area and critical area buffer.
G. Additional Considerations.
1. Site specific considerations may warrant additional performance standards, to be determined during the permit process, to ensure the protection of critical areas.
2. Development specific considerations may warrant additional performance standards based on level of impact to critical areas.