Monthly Operations Summary / History

In addition to the 5 short-term current snapshots of pumping activity (Weekly, 14-day, Monthly, Seasonal, and Yearly), the following operations summary depicts monthly operations (metered usage, raw pumping, system losses, and cumulative pumping) in the context of historical data and most recent MTM (Month to Month) change.  This data was previously reported only to water board directors, but beginning in 2026 has been integrated in the district website.   

In the following charts, operational data for the current water year are represented by the heaviest trend line displayed alongside historical background data from previous years data in lighter traces. The Monthly Operations Summary is updated shortly after every end-of-month meter reading cycle, and provides a simple method for visualization and statistical control of current operational metrics in the perspective of historical data.

Notes on each chart include the following:

Metered Water Usage:  Metered usage measures the monthly volume of water going through customer meters. Because our billing system charges for water usage in 100 gallon increments, aggregate monthly metered usage is slightly overstated due to the fractional up-rounding of monthly readings in 100-gallon increments. The maximum aggregate overstatement is 3,600 gallons (100 gallons x 36 homes), or approximately 2% of average in-house winter usage. 

Aggregate Water Pumping: Aggregate pumping reflects combined monthly pumping from our two wells, as logged from the virtual registers in the SCADA computer that runs our water system.  Pumping activity and volume are monitored daily, and audited weekly against a combined mechanical totalizer. 

System Losses: Because Spring Valley meters are only read at the end of the month, this is the only time system losses can be estimated by subtraction of monthly usage from monthly pumping.  But because pumping is calculated to an exact gallon and billed usage is typically overstated due to up-rounding to 100 gallons, our monthly loss estimate is typically understated to the point that we can theoretically sell more water than we pump, a neat trick.  The conspicuous occasional spikes in our pumping logs typically result from water main breaks, or unlucky customers with in-house plumbing leaks. American Water Works Association (AWWA) statistics suggest that up to a 10% loss allowance is reasonable for small water systems like ours. 

Cumulative Pumping: Spring Valley's augmentation plan for our water decree of 12 acre-feet requires that we report our aggregate pumping weekly, from which our hydrologist can calculate groundwater depletion scaled over a 72-month return cycle.  Because of the 72-month scaling, we watch cumulative pumping very closely to ensure we do not inadvertently exceed our 12 acre-foot adjudication in our water year which runs fron November 1 to October 31 of each year.