Pond Boss Forums POND CONSTRUCTION Building a dam wind pump / river pump?

20 gallons a day is very, very low in the realm of overcoming seepage or evaporation. Pond supply pumps need to deliver in excess of 20 gallons per minute to have much affect.

One neat way to use a flowing stream to pump water is called a "ram pump". There has not IIRC been a whole lot of discussion of ram pumps here, but Dr. Mark Cornwell had an article in the July-August 2008 issue of PBMag that explained the concept behind them and showed pictures of one.