state of California relies on large alluvial aquifer systems to supply its growing
population with water. A combination of very little recharge through
precipitation and a warm, dry climate have resulted in droughts and surface
water shortages, increasing the reliance on groundwater. The demand greatly
outweighs supply, particularly in Southern California where land use is
dominated by agriculture. Agriculture accounts for around 80% of all groundwater
used in the state (Nelson, 2012). The California Department of Water Resources
estimate that groundwater extraction rates exceed natural recharge by two
million acre feet per year (DWR, 2013).
to manage the falling groundwater levels have been in effect for decades. Legislation
was introduced in 1937 and today the California Department of Water Resources
manages the long-term California Water Plan which was last updated in 2013. Groundwater
allocation and regulation to resolve disputes between water users is ongoing. Legislation
plays a key role in California achieving groundwater sustainability, efforts
are hindered until clear criteria for water rights are produced and enforced.
recycling is extensively used for both potable and non-potable water. Artificial
recharge projects are one of the most cost effective solutions for the state,
despite being an expensive technique. Water treatment and artificial injection
both require water transport and storage networks.
water transport and delivery infrastructure in California is one of largest
purpose built water networks in the world. There are two major systems, the
Central Valley Project and the California State Water Project each consisting
of 500 and 700 miles of canals, pipeline and tunnels respectively. The Central
Valley Project has had serious effects on the environment, as a result an act was
passed to change water management practices to lessen the ecological impact (Central
Valley Project Improvement Act, 1992). The California State Project has not met
its projections and is in need of upgrading in many areas. In February 2017, California
submitted a $100 billion federal funding request which included plans to improve
water transit and storage (McGreevy, 2017).
California Water Plan update will be published in 2018 with emphasis expected
to be on sustainability through management.