Lake restoration by dilution: Moses lake, Washington

Eutrophication of Freshwaters

“…Its drawbacks are the possible effects of low temperature, low oxygen and high nutrient water on the receiving stream. The technology is basically simple -a siphon from the deepest part leading to the outflow -and the method has been used successfully in Switzerland and several other European locations (Welch and Patmont, 1980). Lake Bled, Yugoslavia, experienced improved conditions following the introduction of hypolimnetic outflow after inflow flushing from the nearby River Radovna failed to produce any improvement (Vrhovsek et ai., 1985).…”

“…Dilution from this source gave the lake a renewal time of four months and resulted in a reduction of total phosphorus concentration from 60 to 20 !lg/l, chlorophyll from 50 to 10 !lg/l and a transparency increase from 1 to 4 m in three years (Oglesby, 1969). Moses Lake, Washington, was flushed periodically during spring and summer using water from the nearby Columbia river irrigation system producing 40-60% improvement in chlorophyll, phosphorus and transparency (Welch and Patmont, 1980). Hypolimnetic outflow is an alternative method of removing nutrients, usually from deeper eutrophic lakes, when stratification sets in during the summer.…”

The potential impact of an inter-basin water transfer project on nutrients (nitrogen and phosphorous) and chlorophyll a of the receiving water system

“…Previous research in Moses Lake, Washington, U.S.A., showed that when the volumes of dilution water were almost equal to the volume of the lake, the water would be improved as a result of the washout by the dilution water (Welch and Patmont, 1980). Because the total water volumes diverted into Miyun reservoir were approximately 200 million cubic meters a year, which is approximately one fifth of the existing total storage capacity (approximately one billion cubic meters), the affected areas were quite limited.…”

“…Only a few studies have concentrated on the effects of water transfers on the physical and chemical changes to water quality. On the one hand, water transfers can improve the trophic state of the receiving water via dilution (Hu et al, 2008;Welch and Patmont, 1980;Welch et al, 1992;Zhai et al, 2010). The water quality of downstream reservoirs could also be improved by using upstream reservoirs as storage to store nutrient loads (Padisak et al, 2001).…”

Case Study on Water Quality Improvement in Xihu Lake through Diversion and Water Distribution

“…Examples include Moses Lake in Washington, DC, USA, into which a large volume of low-nutrient water from the Columbia River was introduced during the spring and summer of 1977 [24,25]; another water project in the United States that involved diverting the Mississippi River…”