Water Use
The Water Policy and Resources Development Department is responsible for developing viable plans and initiatives to ensure reliability of the region’s water supplies. It plays an important role in reducing the region’s dependence on imported water by expanding the local water supply portfolio in an economically feasible manner. Through effective partnerships and innovative planning, the staff continues to demonstrate a proactive approach to water resource management.
Below you will find the annual Water Supply and Demand Assessment, annual Water Use Report and Drought Rationing Plan. Water use subpages feature the District's Urban Water Management Plan and Water Shortage Contingency Plan.
Annual Water Supply and Demand Assessment
All California urban water suppliers that either provide more than 3,000 acre-feet of water annually or that serve more than 3,000 urban connections are required to conduct an Annual Water Supply and Demand Assessment (AWSDA) and to submit an Annual Shortage Report to the Department of Water Resources (DWR) on or before July 1 of each year.
To complete an AWSDA, West Basin works in close coordination with Metropolitan Water District of Southern California (Metropolitan) and West Basin’s retail water suppliers. The AWSDA process evaluates supplies, projects demand, and identifies potential water shortages and mitigation actions, if needed, for the next year.
In the event of a water supply shortage scenario, West Basin would enact its Water Shortage Contingency Plan (WSCP); implementing local supply augmentation and demand reduction measures, identified in the WSCP, as required.
More information regarding AWSDAs be found on the California DWR website.
Water Use Report
Every year West Basin develops the Water Use Report to inform its customer agencies, Board of Directors and key stakeholders of the service area’s annual water usage as well as its customer agency’s retail usage. It is designed to be a water resource reference tool summarizing the following information:
- 10-year historical water use (imported, recycled, and groundwater)
- Water use by month over the most recent fiscal year
- Tier 1 and commitment amount
- Potable meter connection data
- Imported & recycled water rates & charges
- Contact information
- Recycled water connections
Drought Rationing Plan
The District's Drought Rationing Plan (DRP) was in effect from 2009-2011 (under the name Water Shortage Allocation Plan) and again in 2014-2015.
The methodology used to implement the DRP
Metropolitan's Board of Directors approved an amended Water Supply Allocation Plan in March 2015. It is based on a guiding principle developed almost 15 years prior as part of their Water Surplus and Drought Management Plan.
According to the principle, “Metropolitan will encourage storage of water during periods of surplus and work jointly with its member agencies to minimize the impacts of water shortages on the region’s retail consumers and economy during periods of shortage.”
Fairness in allocation and minimizing regional hardship to retail water consumers remained central themes in the development of a specific formula for allocating shortages across Southern California. The formula uses different adjustments and credits to balance impacts of shortage at the retail level, where local supplies can vary dramatically, and provide equity on the wholesale level among member agencies. It also attempts to account for the growth in demand, local investments, changes in local supply conditions, the reduction in potable water demand from recycled water, and the implementation of water conservation programs.
Based closely on Metropolitan's methodology, West Basin’s Drought Rationing Plan model, adopted by the Board of Directors in April 2009 and amended in March 2015, determines each customer agency’s share of West Basin’s allocation from MWD.