Thunderbird is a 6,070-acre reservoir and is part of the Upper Little River watershed.
Andrew Stoddard of Dynamic Solutions said the computer generated model is a numerical description of the lake’s watershed. Data was collected from various points and fed into the computer modeling program along with other relevant data such as weather, water temperature, water releases at the dam and surveys of the sediment bed.
The Oklahoma Water Resources Board, MESONET, U.S. Army Corps of Engineers and the Central Oklahoma Master Conservancy District contributed data.
The model describes the current conditions based on that data — a year-long segment during 2008-2009 — and makes future projections based on various scenarios, allowing DEQ to make recommendations for reducing pollution based on the model.
Samples taken at various points identified that urban development is the highest contributors to the loading of phosphorus and sediment in the lake. Hot spots for high levels of sediment and phosphorus loading into the lake were identified in northwest Norman, Moore and portions of Oklahoma City.
Norman, Moore and Oklahoma City discharge runoff into the lake’s tributaries through their stormwater systems.
Known as MS4s — Municipal Separate Storm Sewer Systems — these source point polluters will be required to reduce the amount of pollution they discharge into the watershed. DEQ’s proposed requirements include identifying potential sources of pollution, selecting a strategy for reducing the “wasteload” or amount of pollutants, implementing construction site inspections with enhanced enforcement and tracking progress.
Currently, the Central Oklahoma Master Conservancy District that manages the lake is experimenting with an oxygen injection project. The DEQ recommend that be continued, along with expansion of shoreline revegetation. A more long-term project recommended is the establishment of a treatment wetlands on Little River above the Twin Bridges.
Under the proposal, construction sites would have to maintain a 100-foot vegetative buffer for all streams, put in sediment basins (detention ponds) for sites five acres and larger, submit to weekly inspections, plant vegetation quickly and test the soil before using fertilizer.