430.130 Water Quality Resource Areas.
A. The purpose of this Section is to protect and improve the beneficial water uses, functions and values of a WQRA.
B. These provisions establish a WQRA, which is delineated on the WQ Map attached and incorporated by reference as part of this Section.
C. The WQRA is the vegetated corridor and the Protected Water Feature. The width of the vegetated corridor is specified in Table 1 below. At least three slope measurements along the water feature, at no more than 100-foot increments, shall be made for each property for which development is proposed. Depending on the width of the property, the width of the vegetated corridor will vary.
Protected Water Feature Type (see definitions) | Slope Adjacent to Protected Water Feature | Starting Point for Measurements from Water Feature | Width of Vegetated Corridor |
|---|---|---|---|
Primary Protected Water Features1 (Arata Creek) | < 25% | ∙ Edge of bankful flow or 2-year storm level; ∙ Delineated edge of Title 3 wetland | 50 feet |
Primary Protected Water Features1 | ≥ 25% for 150 feet or more5 | ∙ Edge of bankful flow or 2-year storm level; ∙ Delineated edge of Title 3 wetland | 200 feet |
Primary Protected Water Features1 | ≥ 25% for less than 150 feet5 | ∙ Edge of bankful flow or 2-year storm level; ∙ Delineated edge of Title 3 wetland | Distance from starting point of measurement to top of ravine (break in ≥ 25% slope)3 plus 50 feet4 |
Secondary Protected Water Features2 (No-name Creek) | < 25% | ∙ Edge of bankful flow or 2-year storm level; ∙ Delineated edge of Title 3 wetland | 15 feet |
Secondary Protected Water Features2 | ≥ 25%5 | ∙ Edge of bankful flow or 2-year storm level; ∙ Delineated edge of Title 3 wetland | 50 feet |
1Primary Protected Water Features include: all perennial streams and streams draining greater than 100 acres, Title 3 wetlands, natural lakes and springs.
2Secondary Protected Water Features include intermittent streams draining 50-100 acres.
3Where the Protected Water Feature is confined by a ravine or gully, the top of the ravine is the break in the ≥ 25% slope (see slope measurement in Appendix).
4A maximum reduction of 25 feet may be permitted in the width of vegetated corridor beyond the slope break if a geotechnical report demonstrates that slope is stable. To establish the width of the vegetated corridor, slope should be measured in 25-foot increments away from the water feature until slope is less than 25% (top of ravine).
5Vegetated corridors in excess of 50-feet for primary protected features, or in excess of 15-feet for secondary protected features, apply on steep slopes only in the uphill direction from the protected water feature.
(Note: The following methodology is an alternative for the purposes of substantial compliance: a jurisdiction can meet the performance standards in Title 3 by applying the following method to the water quality resource area: for areas with zero slope (as measured parallel to the ground) the buffer will be 50 feet from top of waterway bank, but for every one percent (1%) slope after that point, add six (6) feet).