Riparian Corridor Conservation District
Surface Water Feature | Minimum Corridor Width |
|---|---|
1. Perennial streams: All perennial streams identified in the soil survey.1 (Perennial streams are shown as solid lines on the soil survey1). | Zone 1: Minimum width of 25 feet from each defined edge of the watercourse at bank full flow, measured perpendicular to the edge of the watercourse. |
Zone 2: Minimum width of 50 feet from, the outer edge of Zone 1 on each side of the stream, measured perpendicular to the edge of Zone 1, or equal to the extent of the one-hundred-year floodplain,3 or 25 feet beyond the outer edge of a wetland along the stream, whichever is greater. | |
Zone 3: Width varies. Extends outwards from Zone 2 on each side of stream where upslope areas adjacent to Zone 2 are being disturbed during land development and where direct discharge of stormwater would otherwise occur. | |
2. Intermittent streams: Intermittent streams identified in the soil survey or any stream otherwise identified on the applicant's plan that have an upstream drainage area of 75 acres or more.2 | Zone 1: Minimum width of 25 feet from each defined edge of the watercourse at bank full flow, measured perpendicular to the edge of the watercourse. |
Zone 2: Minimum width of 50 feet from the outer edge of Zone 1 on each side of the stream, measured perpendicular to the edge of Zone 1, or equal to the extent of the one-hundred-year floodplain, or 25 feet beyond the outer edge of a wetland along the stream, whichever is greater. | |
Zone 3: Width varies. Extends outwards from Zone 2 on each side of stream where upslope areas adjacent to Zone 2 are being disturbed during land development and where direct discharge of stormwater would otherwise occur. | |
3. Other intermittent streams: All other streams with an upstream drainage area of less than 75 acres, including intermittent streams identified in the soil survey. | Zone 1: Minimum width of 25 feet from the center line of the watercourse, measured perpendicular to the center line of the watercourse, or equal to the extent of the one-hundred-year floodplain,3 or 25 feet beyond the outer edge of a wetland along the stream, whichever is greater. |
Zone 2: Does not apply. | |
Zone 3: Width varies. Extends outwards from Zone 1 where upslope areas adjacent to Zone 1 are being disturbed during land development and where direct discharge of stormwater would otherwise occur. | |
4. Wetlands and water bodies: Wetlands not located along a stream, and water bodies, where the wetland and/or water body is greater than 10,000 square feet in area. | Zone 1: Minimum width of 25 feet from the outer edge of the wetland or water body, measured perpendicular to the edge. For wetlands located at the edge of a water body, the measurement shall be made from the outer edge of the wetland. |
Zone 2: Does not apply. | |
Zone 3: Width varies. Extends outwards from Zone 1 where upslope areas adjacent to Zone 1 are being disturbed during land development and where direct discharge of stormwater would otherwise occur. |
NOTES: |
|---|
1 "Soil survey" shall mean the most recent edition of the Soil Survey of Montgomery County, prepared by USDA's Soil Conservation Service. |
2 Upstream drainage area shall be measured from where the stream exits the applicant's site. |
3 One-hundred-year floodplain is identified on the Flood Insurance Rate Map (FIRM) prepared by FEMA, or as calculated by the applicant where FEMA data does not apply. |
Riparian Corridor Conservation District
Surface Water Feature | Minimum Corridor Width |
|---|---|
1. Perennial streams: All perennial streams identified in the soil survey.1 (Perennial streams are shown as solid lines on the soil survey1). | Zone 1: Minimum width of 25 feet from each defined edge of the watercourse at bank full flow, measured perpendicular to the edge of the watercourse. |
Zone 2: Minimum width of 50 feet from, the outer edge of Zone 1 on each side of the stream, measured perpendicular to the edge of Zone 1, or equal to the extent of the one-hundred-year floodplain,3 or 25 feet beyond the outer edge of a wetland along the stream, whichever is greater. | |
Zone 3: Width varies. Extends outwards from Zone 2 on each side of stream where upslope areas adjacent to Zone 2 are being disturbed during land development and where direct discharge of stormwater would otherwise occur. | |
2. Intermittent streams: Intermittent streams identified in the soil survey or any stream otherwise identified on the applicant's plan that have an upstream drainage area of 75 acres or more.2 | Zone 1: Minimum width of 25 feet from each defined edge of the watercourse at bank full flow, measured perpendicular to the edge of the watercourse. |
Zone 2: Minimum width of 50 feet from the outer edge of Zone 1 on each side of the stream, measured perpendicular to the edge of Zone 1, or equal to the extent of the one-hundred-year floodplain, or 25 feet beyond the outer edge of a wetland along the stream, whichever is greater. | |
Zone 3: Width varies. Extends outwards from Zone 2 on each side of stream where upslope areas adjacent to Zone 2 are being disturbed during land development and where direct discharge of stormwater would otherwise occur. | |
3. Other intermittent streams: All other streams with an upstream drainage area of less than 75 acres, including intermittent streams identified in the soil survey. | Zone 1: Minimum width of 25 feet from the center line of the watercourse, measured perpendicular to the center line of the watercourse, or equal to the extent of the one-hundred-year floodplain,3 or 25 feet beyond the outer edge of a wetland along the stream, whichever is greater. |
Zone 2: Does not apply. | |
Zone 3: Width varies. Extends outwards from Zone 1 where upslope areas adjacent to Zone 1 are being disturbed during land development and where direct discharge of stormwater would otherwise occur. | |
4. Wetlands and water bodies: Wetlands not located along a stream, and water bodies, where the wetland and/or water body is greater than 10,000 square feet in area. | Zone 1: Minimum width of 25 feet from the outer edge of the wetland or water body, measured perpendicular to the edge. For wetlands located at the edge of a water body, the measurement shall be made from the outer edge of the wetland. |
Zone 2: Does not apply. | |
Zone 3: Width varies. Extends outwards from Zone 1 where upslope areas adjacent to Zone 1 are being disturbed during land development and where direct discharge of stormwater would otherwise occur. |
NOTES: |
|---|
1 "Soil survey" shall mean the most recent edition of the Soil Survey of Montgomery County, prepared by USDA's Soil Conservation Service. |
2 Upstream drainage area shall be measured from where the stream exits the applicant's site. |
3 One-hundred-year floodplain is identified on the Flood Insurance Rate Map (FIRM) prepared by FEMA, or as calculated by the applicant where FEMA data does not apply. |