How not to protect groundwater : messages from California

Posted on March 28, 2013


The extraction of underground water meets 40% of global needs for drinking and irrigation.  Unfortunately however, excessive groundwater pumping is responsible for a number of serious environmental problems, including land subsidence, seawater intrusion and changes to aquatic ecosystems.  While global recognition of such problems is gradually leading to legislative reform, in many jurisdictions the reform process is being hampered by outdated institutional laws.   For example, in California, where pumping has reduced groundwater levels by over 60 m in places, there is no uniform groundwater extraction legislation, and the responsibility for groundwater management rests with a proliferation of small independent local agencies, with only minimal oversight by the State government. Although many countries have laws that limit groundwater pumping to a “safe yield”, where extraction is matched to the rate of recharge to the aquifer, such measures are uncommon in California.  Further, in that state no water agency has powers to consider non-supply issues, such as the ecological and social effects of groundwater depletion.  Information on groundwater extraction is patchy because of deficiencies in well metering and reporting.  Stakeholder engagement is often limited because groundwater managers restrict membership of advisory groups to local landowners.  And it seems that due to political and electoral pressures, local agencies are typically reluctant to use the legal powers vested in them by State government to prevent over-extraction of groundwater.

Reference:   Nelson, R.L.  2012.  Assessing local planning to control groundwater depletion: California as a microcosm of global issues.  Water Resources Research 48, W01502, doi:10.1029/2011WR010927, 2012.

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