The National Environmental Science Center campus (NESC) required an alternative water source due to the loss of capacity of the well in the Chinquapin water system that was to be the source of water for the campus. Water supply alternatives that were being explored include drilling additional wells or annexation to the County of Mariposa. Each water supply alternative requires an understanding of the water demand anticipated for the NESC campus. We prepared a peer review for the water demand analysis for the new NESC campus located at Henness Ridge in Yosemite National Park and operated by Nature Bridge.
The previous water demand analysis methodology consisted of preparing a campus wide water fixture count and interviewing Nature Bridge administrative staff to understand water use and typical procedures that would be used to guide water use and conservation. The results of the previous water demand analysis identified a base water demand of 20 gallons per day per capita (gpcd) and after adding a factor of safety the final estimated water demand was stated to be 30 gpcd. The goal of the peer review is to perform an evaluation of the Provost & Pritchard water demand analysis to provide a second professional viewpoint.
Based on our review of the Provost & Pritchard water demand estimation methodology, a site visit, our understanding of the recorded water demand for the Crane Flat campus, and an internet search related to other recreation campground water use studies- the estimated water demand for the new NESC campus would be in the range of 25-50 gpcd. The new NESC campus has built in water demand controls campus-wide, an integrated program philosophy of water conservation, and limited hours of water use. Subsequently, the water demand will be on the low end of the water use range of 25-40 gpcd.
Overstating or understating the water demand has different impacts. Neither serve the camp users beneficially. Overstating water demand results in a costly over-sized water system and understating water demand negatively impacts the health and safety of the camp users. Water industry professionals estimating water use a reasonable safety factor to ensure water demands are not understated. Therefore, the Provost & Pritchard water demand estimate of 30 gpcd was determined to be reasonable.
Scope of services:
- Project management
- Research water demands for campgrounds
- Hydraulic analysis
- Develop report figures
- Prepare Analysis Report