Setback Requirements in the Wetlands and Resource Conservation (WRC) District
The Wetlands and Resource Conservation (WRC) district in the City of Concord does not have a single, fixed numerical setback value; rather, development setbacks are determined through a site-specific hydrologic study. These setbacks are calculated based on the height of the top of the bank above the channel invert for unimproved channels to protect ecological integrity and water quality [Section 18.305.040].
Setback Determination for Unimproved Channels
In the Wetlands and Resource Conservation (WRC) district, the "structure setback line" for unimproved earth channels is determined by the horizontal distance from the top of the bank. This distance is calculated based on the height of the top of the bank above the channel invert, as outlined in the following table:
| Height of Top of Bank Above Channel Invert | Horizontal Distance Between Top of Bank and Setback |
|---|---|
| Less than 20 feet | 30 feet |
| 20 feet – 29.99 feet | 35 feet |
| 30 feet – 39.99 feet | 40 feet |
| 40 feet – 49.99 feet | 45 feet |
| 50 feet and greater | 50 feet |
Where significant riparian vegetation exists beyond these defined distances, the review authority may require additional setbacks in the Wetlands and Resource Conservation (WRC) district to preserve that existing vegetation [Section 18.305.040].
Restrictions Within Setback Areas
In the Wetlands and Resource Conservation (WRC) district, permitted use of the structure setback area is strictly limited. While paths or trails are permitted within a structure setback in the Wetlands and Resource Conservation (WRC) district, the construction of roads, parking areas, parking spaces, or any other paved area is prohibited within the setback area [Section 18.305.040].
Furthermore, within the structure setback area in the Wetlands and Resource Conservation (WRC) district, grading, filling, or the removal of native vegetation is prohibited, except where authorized for flood control purposes with the proper permits from the California State Department of Fish and Game and other applicable agencies [Section 18.305.040].
Hydrologic Study Requirement
To determine the precise locations for the waterway centerline and the structure setback line, every application for a development project in the Wetlands and Resource Conservation (WRC) district must include a site-specific hydrologic study. This study must be prepared by a qualified professional (such as a hydrologist or civil engineer) and approved by the City of Concord [Section 18.305.030].
Sections Cited
- Section 18.305.030 (Hydrologic study)
- Section 18.305.040 (Development standards)