The impacts of pumping groundwater on surface water, ecosystems, and surface water rights holders are generally under-recognized in California, yet they cause significant conflict. These groundwater connection conflicts are surprisingly common.
Groundwater depletion is often only thought to impact people who use groundwater. In fact, depletion can also affect rivers, species, ecosystems, and surface water users. Many rivers receive some or even most of their flow from groundwater, particularly during the driest months. In addition, California is home to a surprisingly diverse and widespread number of groundwater-dependent species and ecosystems (GDEs), some of which are endangered.
The impacts of pumping groundwater on surface waters, ecosystems, and surface water rights holders are generally under-recognized in California, yet they cause significant conflict. These groundwater connection conflicts are surprisingly common.
Unfortunately, California’s legal toolbox is seriously under-equipped to consider and deal with the types of impacts that underlie these conflicts. California water law almost totally ignores these impacts, leaving conflicts to be resolved through laws that are not tailored to the problem. While thoroughly dealing with these conflicts would require fundamental legal reform, significant improvements could be made by extending the reach of existing legal approaches and implementing complementary new policies.
Signed into law in September 2014, the Sustainable Groundwater Management Act requires managing connected groundwater and surface waters. Groundwater Sustainability Plans must avoid "undesirable results," one of which is surface water depletions that adversely impact beneficial uses of surface water.
This interactive map reflects the first study on groundwater connection conflicts in California. Based on a dataset of 55 conflicts drawn from publicly available information collected from 2008 to 2012, the map shows where these conflicts occur, what the problems are, and how they are dealt with. The map allows users to explore the individual conflicts by ecosystem type, category of groundwater or surface water user, and type of legal or policy tool invoked to deal with the conflict. The map also crowd-sources additional information about recent groundwater connection conflicts in California by allowing users to suggest additional conflicts or add information to those that are shown.
Since California law does not routinely require a permit to pump groundwater, no law deals comprehensively with the impacts of pumping on surface water rights or ecosystems, or the resulting conflicts. Analyzing the conflicts shown on our map shows that consideration of the impacts of groundwater pumping on surface water rights and groundwater-dependent species and ecosystems is largely done incidentally through laws that apply to specific activities, or activities in specific places or undertaken by specific entities. This leaves many gaps in terms of the geographies and activities covered.
Laws that commonly arise in the context of the mapped conflicts are environmental impact assessment laws — the California Environmental Quality Act (CEQA) and the National Environmental Policy Act (NEPA) — the limited state permitting powers in relation to groundwater, and endangered species protections. However, CEQA and NEPA are only triggered where a project involves government action, and harm to endangered species represents only a small subset of environmental impacts that are assessed.
Agricultural irrigation, which accounts for most groundwater pumping in California, rarely triggers either set of laws, and its impacts are rarely scrutinized. Beyond laws, no policies deal with impacts on surface water rights or groundwater-dependent ecosystems, or the resulting conflicts. Yet there are frequent arguments that good policy can avoid the need for groundwater regulation. The state’s failure to examine the impacts of pumping groundwater on surface water rights and groundwater-dependent ecosystems produces significant potential for pumping to impact these assets, in circumstances under which their owners and advocates have little power to do anything about it.
Even when existing legal tools cover these impacts of groundwater pumping, it can be challenging to use them. Some problems relate to information: low levels of awareness that rivers and other ecosystems can be harmed by pumping, and little data about the precise nature of impacts. Other problems stem from legal vagueness or agency attitudes. Laws usually lack quantitative standards for acceptable levels of impact, and impact assessments can be inconsistent among agencies and over time. Project conditions that require “mitigation” of potential impacts on groundwater-dependent ecosystems are often just monitoring requirements that lack triggers for specific action if particular physical conditions appear. Federal agencies can be reluctant to assert their rights in the case of “federal reserved rights” that can protect the flow of rivers that support key wilderness values.
There are two fundamental ways to improve how California law and policy consider and manage the impacts of pumping groundwater on rivers and the environment. The first “low-hanging fruit” approach is to ensure that agencies that currently consider groundwater pumping projects consistently consider and deal with impacts on surface water rights and groundwater-dependent ecosystems. This could be done by amending and expanding the existing CEQA environmental checklist, the Department of Water Resources’ “Required and Recommended Components of Local Groundwater Management Plans,” and its Groundwater Management Model Ordinance to require consideration and management of these impacts. If there is the potential to adversely affect surface water rights, a prospective pumper could be required to offset or otherwise compensate for these effects, a practice in many Western states. If there is potential to adversely affect groundwater-dependent ecosystems, comprehensive monitoring conditions on projects should be linked to clear and specific remedial management actions, like cease-to-pump rules based on quantified ecological triggers.
A more ambitious approach to improving law and policy would be to develop new laws and policies that connect groundwater pumping, rivers, and ecosystems where these conceptual connections currently do not generally exist. This requires an increased level of political coordination and will. Options include:
Nonregulatory policy mechanisms, like grant-making activities, technical assistance programs, and industry-led guidance, would also assist, as would producing and better distributing information about groundwater-dependent species or ecosystems. Work mapping the density of GDEs in California could form the basis of an electronically searchable “California Atlas of Groundwater-Dependent Rivers and Ecosystems,” as has been done elsewhere.
In California, the significant impacts on surface waters, ecosystems, and surface water rights from pumping groundwater are seldom recognized. Law and policy to consider and deal with the underlying impacts are grossly under-developed. Understanding the nature of these conflicts, and the laws and policies that are being used or could be used to address them, can help shape better laws and policies for preventing and dealing with them. Multiple paths to better laws and policies have already been charted to address this critical need. Now we just need to follow them.