The lake consumes water to the extent that all the water in the lake must be replenished every year. Regarding water evaporation, lake documents state that according to the USDA Water Conservation Laboratory in Phoenix, the mean annual evaporation rate for Sahuarita is per year. This results in a mean water loss of per year. Regarding water loss due to seepage, initial estimates indicated an annual loss of of water, or 17% of total capacity per year. The J. Harlan Glenn Engineers that provided this estimate indicated that this equates to an "extremely low seepage rate". On average, 65 gpm (gallons of water per minute) must be pumped into the lake to maintain its current level. A nearby well site that draws on the shared Upper Santa Cruz Valley aquifer is used to refill the lake. In 2006, of water was used for the entire Sahuarita lake park, which includes water for the of grass and restroom facilities.