Lowden Field Wetland Enhancement Project

Lowden Field Wetland Enhancement Project

This project will restore approximately 15 acres of degraded wetland habitat. Using an existing culvert, a portion of the runoff water from intermittent Snipe Gulch Creek will be diverted into an existing degraded emergent palustrine wetland. Snipe Gulch Creek is a tributary of the Trinity River. The amount of runoff water diverted will be controlled by installing a flashboard riser in an existing drainage ditch. This drainage ditch is located between two large spoil banks. Minor earth moving activities will occur to install the flashboard riser. The flashboard riser will have a 48-inch height and a 36-inch width, and will be installed in a drainage ditch that is about 6 feet wide and 3 feet deep. The maximum dimensions of ground disturbance for this project will be approximately 16 feet x 5 feet (80 square feet). At a maximum excavation depth of 5 feet, this would equate to a maximum volume of 400 cubic feet, or about 15 cubic yards. No other ground disturbing activities or construction activities will occur. The ground excavation will be conducted with a backhoe during the dry season, so wetland soils will not be rutted. Any needed fill will be obtained from offsite, and any excess fill will be deposited offsite. The construction site is located in a drainage ditch which flows between two large spoil banks. Construction activities will only occur in this previously-disturbed location. This project will not reach beyond the limits of prior land disturbance. No improvements are required for site access, materials storage, or construction staging. Project construction/installation will occur during daylight hours. All construction/earthmoving will occur under ditch dry conditions. Likely, the increased water presence resulting from the proposed project will enlarge the aerial extent and raise the water table level of the existing wetlands. The wetland dimensions and water table level likely will be returned to dimensions that are similar to their historic, pre-disturbance dimensions. While the construction footprint will be limited to approximately 80 square feet, the resulting wetland enhancement will increase soil saturation and inundation on 15 acres of historic wetlands. A backhoe will be used for excavation of structures and backfilling/leveling. Disturbed areas will be backfilled, leveled, and revegetated as needed. Potential site impacts include minor temporary disturbance of the ground surface within the excavated area and a temporary increase in noise levels during construction. Best Management Practices to reduce erosion and sedimentation have been incorporated into the project design including; project siteing, construct methods, and timing. The proposed location is located on State lands and is being constructed with the landowner's permission. Field surveys for State and federally "listed" plants and animals, jurisdictional wetlands and archaeological resources were completed at the proposed project area, with no unavoidable adverse impacts identified. A U.S. Army Corp of Engineers 404 Nationwide Permit has been approved for the project. No mature or scenic trees will be removed. The project purpose is to restore a degraded wetland. The restored wetland is expected to provide improved wildlife habitat and water quality.

Trinity