Design criteria for drinking water systems at recreation developments, particularly summer home type, cause frequent confrontations with regulatory agencies. Developers claim extremely low water use rates due to low occupancy rates, but regulatory agencies are concerned about changes over time from essentially weekend use to more permanent residency and also about occasional peak day water demands similar to those of municipal systems. Little empirical data have been available to resolve such questions. This study included the gathering and analysis of both historic water use measurements and additional daily and instantaneous measurements during peak seasons at 11 Utah and one Wyoming recreation development. The water demand parameters studied included average, peak month, peak day, and instantaneous events at mountain cabins, resort condominiums, marinas, and recreation vehicle campgrounds. The results are compared to existing design criteria of the Utah Division of Environmental Health
