Conservation Standard Self Certification

Recognizing persistent yet less severe drought conditions throughout California, on May 18, 2016, the State Water Board adopted an emergency water conservation regulation that replaces the February 2 emergency regulation. The May 2016 regulation requires locally developed conservation standards based upon each agency’s specific circumstances. It replaces the prior percentage reduction-based water conservation standard with a localized “stress test” approach. Each water supplier is required to evaluate its supply portfolio and self-certify the accuracy of its information; the State Water Board assigns each supplier a mandatory conservation standard equal to the percentage deficiency the supplier identifies in its supply under certain specified assumptions. See this webpage Water Conservation Portal for more information on the May 2016 emergency regulation. The new conservation standards take effect in June and remain in effect until the end of January 2017.


The regulation requires individual urban water suppliers to conduct a stress test and self-certify the level of available water supplies they have assuming three additional dry years, as well as the level of conservation necessary to assure adequate supply over that time. Suppliers that would face a shortage after a third dry year are required to comply with a conservation standard equal to the amount of that shortage. Water supply reliability after the 2018-19 winter is calculated as follows:

  • The supply projection for the next three years is based on current supply conditions plus an assumed three-year hydrology mirroring the 2012-13, 2013-14, and 2014-15 water years. (A water year runs from October 1 through September 30).
  • No temporary change orders that increase the availability of water to any urban water supplier are issued in the next three years.
  • Demand over that same period is based on each supplier’s average total potable water production for calendar years 2013 and 2014.
  • Suppliers factor into their calculations all of their water sources that are realistically capable of being treated to potable standard during the three-year projected period.
  • Supplier’s conservation standards are calculated as a percentage and rounded to the nearest whole percentage point.
  • Suppliers self-certify accuracy of their conclusions and provide their analysis and supporting data to the State Water Board and at a publicly available website.
  • The State Water Board posts information provided by suppliers on its website and assigns each supplier, as a mandatory conservation standard, reductions equal to the supplier’s projected percentage deficiency in supply at the end of the third dry year.
  • Wholesale water suppliers are required to make projections about how much water they would deliver to retail water suppliers under the three-dry-years scenario. While the wholesale suppliers may aggregate water supply production data for a region, they will need to assign how the water would be apportioned among retailer water suppliers that are its customers (e.g., using the same apportionments as in water years 2013, 2014, and 2015.)
  • Additionally, if a wholesaler in a region, along with every one of its urban water supplier customers in that region all agree, in a legally binding document, those suppliers and wholesaler may submit an aggregate stress test and conservation standard. While the conservation standard would be in lieu of an individual conservation standard, the submittal shall include all the supporting documentation required of each retail supplier covered by the aggregated conservation standard for individualized self-certified conservation standards, and responsibility for compliance remains ultimately on the individual water suppliers.

Moulton Niguel Water District has submitted self-certification and provided required data regarding supply reliability to comply with the requirements of Section 864.5 of the Drought Emergency Water Conservation regulation adopted by the State Water Board on May 18, 2016. The self-certification application and supporting data are linked below.

MNWD Conservation Standard Self-Certification

MNWD Total Available Supply

SWRCB MWD Supplies Available to Urban Water Suppliers

SWRCB MWD Analysis and Supporting Documentation

Wholesaler Supply Information – MWDOC



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