San Cristobal Operation Manual
Yearly Water Use
There are 55 active users on the SCMDWCA. Yearly system water consumption is on average is a million gallons/year.
A small flow from the stream is diverted into an infiltration gallery (installed in 1974) where water is collected by a 10-foot-deep perforated pipe and gravity flows to the treatment vault where it is chlorinated and stored in a 10,000-gallon storage tank at the head of the valley. The water system operates entirely on gravity. Minimal electricity is used for the chlorine pump.
In 2014 and 2017, community members have measured stream water flow both above and below the infiltration gallery to see how much water is used by the domestic water system. On March 14, 2014, stream flow measured roughly 1.9 cubic feet/sec above the gallery and roughly 1.9 cubic feet/sec below the gallery. The difference in flow was negligible. Water engineers from Martin and Martin engineering stated that once the infiltration gallery is saturated, water will take the path of least resistance which is above the gallery bed. When the water tank is filled, there is no longer draw down in the gallery and water flows over the infiltration gallery and back into the stream – the path of least resistance.
Measuring the stream water flow on March 14, 2014 (a period of low flow before snow run-off) was 1.9 cubic feet per second, the amount of water flowing in the stream over a 24-hour period was estimated to be 1,286,000 gallons/day. This one-day flow in March, if captured, would be more than enough to supply the San Cristobal water system for an entire year.
The SCMDWCA was established and constructed in 1974 with the intent to provide water for families that could not afford to dig wells and were struggling with low flow and contaminated hand-dug wells. The entire community supported the establishment of the system with both financial and water rights contributions.
For more information, you can get first-hand information from Theresa Medina Mitchell who as a little girl went around with her father gathering donations and signatures of support from the entire San Cristobal community.
Data Table: 1,000,000 gallon/year (average yearly usage since 2012)
2,740 gallons/day domestic usage of the March 14th stream flow of 1,286,000 gallons/day.
The Domestic Water users of San Cristobal (along with the San Cristobal volunteer fire department) continue to thank the community of San Cristobal for their continued support.
San Cristobal Mutual Domestic Water Consumers 