How Much Water Do We Use?

• Share

There are an infinite number of reasons people don’t pursue the facts necessary to make an informed decisions. Some of the reasons are even reasonably valid. (Of course, readers of this site value the access to information needed to make good decisions.) In reality, a majority of folks rely mostly on what they hear from their friends and neighbors, filtered through the their own life experiences.  Sometimes, people add what they learn on paper and online.  It often boils down to sound bites and choosing a side based on what your friends have chosen.

Here are some facts: In 2000 Kennedy-Jenks provided a report that has been the basis for the declaration of the Water Code 350 Emergency and the decision to pursue desalination. The report was part of developing a water master plan and included analysis of water use demand. It reported the average residential connection used about 9 units per billing cycle. They calculated a composite connection use of about 12 units, a number often given as “standard” use.  This “composite connection” was calculated

using the “mean annual” unit demand patterns, and assuming residential connections and commercial connections of 3,586 and 210, respectively, (i.e. their December 1999 values), the estimated residential, commercial, and total annual water demand are 578, 201, and 779 acre-feet, respectively. Dividing these values by the assumed number of connections produces annual residential and commercial unit water demand estimates of 0.161 and 0.959 acre-feet per connection, respectively.

In a recent study (Mayer et al, 1999), the indoor water requirements of 12 utilities were evaluated. One of the locations was Lompoc, California. The results of the evaluation are presented in Table 4-1. The mean daily per capita indoor water for the 12 locations was 69.3 gallons per capita per day (gpcd). The comparable use for Lompoc was 65.8 gpcd*, slightly less than the average. The indoor water uses are almost exclusively for human consumption and sanitation.

For comparison, the typical average annual water demand, both indoor and outdoor, for District customers is approximately 75 gpcd. Because a Dry Season water demand reduction of approximately 20 percent would be necessary to reach the indoor water use estimates, the declaration of a water shortage emergency for health and safety reasons would only be necessary for Stage 3.

*gpcd = gallons per capita per day

Translating gpcd into what you would see on your CCSD bill (which covers 2 months).  A CCSD billing unit is one hundred (100) cubic feet of water or 748 gallons.

65.8 gpcd = 5.4 units pcbm (per capita bi-monthly)

65.8 gpcd = 5.7 units pcbm (per capita bi-monthly)

75 gpcd = 6.1 units pcbm (per capita bi-monthly)

50 gpcd  = 4.1 units pcbm (per capita bi-monthly)

Last 5 posts by Amanda Rice

• Gail Robinette Chosen to Complete DeMicco's Term as CCSD Director on Unanimous Vote
• California Coastal Commission Unanimously Denied Army Corps Desal Tests
• Cambria CSD Agenda for November 27, 2011 Meeting Includes Water Conservation & New Tank Project
• Sunken Oil Tanker Off Cambria's Coastline Will Be Checked Again Soon