For example, Taylor cites a 1997 study by Maxted and Shaver of eight watersheds. Two of the watersheds had been retrofitted with retention basins to control storm water. Results of the study showed that using the BMPs did not benefit the receiving waters. The researchers point out that watershed systems are so complex, they can't really be understood with a single data set. But, the results seem to be similar to what we're seeing here in the Tahoe Basin.
Roadways are large generators of storm water flow and cleaning that water is important.
Various pollutants from autos are deposited on roadways. Deicing chemicals and sand are spread on them. And they act as a conduit for overland flows containing nutrients and toxic substances. The most commonly used devices to control runoff from streets and highways are drop inlets. Runoff flows into the inlets, which are installed along the roadside, and silt is trapped in baskets, bags, or trays.