By William Jaeger
Managing water resources sustainably is an enormous challenge facing societies today, and groundwater systems are particularly difficult because they are hidden below ground and are thus poorly understood. Many communities worldwide are dependent on groundwater for agricultural, municipal, and domestic uses, and they support aquatic habitats and other groundwater‐dependent ecosystems (GDEs). Yet groundwater systems continue to be depleted, imposing rising costs on rural communities, farmers, the environment, and public welfare generally. This critical resource provides water to 90% of water supply systems in the U.S. and many of these have become depleted in the last few decades (New York Times, 2023). Declining groundwater levels in the western U.S. threaten drinking water, residential wells, agricultural productivity, environmental flows, groundwater-dependent ecosystems, and they have caused land subsidence resulting in damaged infrastructure and losses in property values.
In Oregon there has been an increase in the number of basins experiencing serious groundwater problems, as reflected in their being designated by the state as “areas of concern”, “significant concern”, “yield-limited”, and “groundwater restricted areas,” as in the map below for 2021.
The Groundwater Act of 1955 gives the state the right to control all sources of water supply, and identifies three primary groundwater policy goals: i) to protect existing water rights (according to seniority under the prior appropriations doctrine), ii) to maintain reasonably stable groundwater levels, and iii) to preserve the public welfare, safety and health. Despite these mandates, there are a number of critical groundwater areas in the state where reasonably stable groundwater are not being maintained. For example, in Cow Valley which was the first basin to be designated a critical groundwater area in 1959, groundwater levels have continued to decline. So why is Oregon failing to fulfill its stated groundwater objectives?
There appear to be four factors that combine to make current approaches to groundwater management in Oregon problematic and ineffective.
The first factor is the long delay that commonly occurs between the time when groundwater pumping has exceeded sustainable rates and the time when the evidence of declining groundwater levels is evident (as much as 20 years later in some cases). This problem is somewhat unavoidable given the complex hydrology of groundwater that it is hidden below ground.
The second factor involves the corrective mechanisms under Oregon water law intended to regulate groundwater use. The seniority system under the prior appropriations doctrine was originally developed for surface water, and that is what Oregon and most western states use to allocate surface water: water users have a seniority ranking or “priority date” which gives senior water rights priority over junior rights when shortages occur. Water use is easily observable, and so too is interference between junior and senior water right holders. When there is not enough water for all users, junior water rights are shutoff in a matter of days or weeks to allow senior water right holders to divert their permitted amounts. The rules trigger timely reductions in water use, and they are transparent, predictable, and enforceable.
But in 1955 Oregon chose to apply this same prior appropriations seniority system for groundwater. The problems with this should be obvious: interference between and among users can take a long time to arise, it is not directly observable, interference in a given basin can involve hundreds or thousands of wells, and the impact of one well on another cannot be proved to a legal standard.
Hence, the system for regulating demand when it exceeds supply is unworkable. There is effectively no enforcement of the groundwater seniority system, and as a result no regular, transparent, predictable means of maintaining stable groundwater levels as required by law.
Third, the mandate to maintain reasonably stable groundwater levels is ambiguously defined. There is no requirement or guidelines about the length of time regulators can take to correct a situation when groundwater levels are observed to be declining, nor about what levels of groundwater stocks need to be maintained. Currently regulators can take decades to stabilize groundwater under the law, and ultimately at levels so low that they deny access to water for many senior water right holders, deplete surface water rights, degrade groundwater-dependent ecosystems, and fail to preserve the public welfare. The rules also provide no clear benchmarks or basis for holding authorities responsible for fulfilling their mandates.
Fourth, given the absence of regular, timely corrective mechanisms like those for surface water rights, the state has created several ad hoc designations for problematic groundwater basins (e.g., critical groundwater areas, groundwater limited areas), an approach that is reactive rather than predictive or proactive. These designations initiate processes that have been described as “arduous, contentious, and costly undertakings.” Moreover, they do not trigger programmed corrections, but can instead create openings for lobbying, negotiation and delays that may prioritize the interests of some water right holders over others in ways unrelated to their seniority.
Taken together these factors leave Oregon’s groundwater systems vulnerable to overappropriation and depletion. Indeed, the current situation in the Harney Basin is an unfortunate example of this, and a cautionary illustration of the harms and injustices that can be inflicted on many parties involved as a result. In the Harney Basin, permitted groundwater pumping rates exceeded sustainable levels in the early 1990s (see figure below), but the impact on groundwater levels was not generally recognized until about 2015 at which point permitted pumping was nearly double sustainable levels. This led to multi-faceted, multilayered efforts to better understand the situation and to find a solution agreeable to stakeholders in the basin.
These efforts included a research project I led over the past five years to develop a hydro-economic computer model of the Harney Basin’s groundwater situation. Collaborating with colleagues at OSU and with US Geological Survey hydrologists, a three dimensional dynamic model simulated different scenarios to better understand the past and current situation and also to evaluate possible future solutions (see this reference listed below). In addition to groundwater decline causing rising costs and lower well yields for irrigators, many domestic wells have gone dry, and springs and lowland flows contribution to the Malheur Wildlife Refuge have declined by one-third. Our study concluded that there are no low-cost ways to stabilize groundwater in the basin. Irrigation pumping needs to be reduced by about 43%.
The basin designations of “serious concern” described as “arduous, contentious, and costly undertakings” have certainly been that in the case of the Harney Basin. As of today, after hundreds of hours of meetings and negotiations, two competing proposals are under review by the Oregon Water Resources Department, both call for a slow, 30-year phase-in of limitations on pumping beginning in 2028 and concluding in 2058. This slow pace will mean years of continued declines in groundwater levels, additional domestic wells going dry, and additional reductions to springs and lowland flows serving groundwater-dependent ecosystems. Many irrigators will suffer reduced well yields, higher pumping costs, and reduced farmland values. And, despite the long phase-in of the regulations, neither proposal will actually stabilize the groundwater system according to our model results.
The situations in the Harney Basin and in other Oregon basins make clear the need for a change in the rules governing groundwater. There are easy-to-describe alternatives that would make timely groundwater management adaptive and predictable so that the objectives of protecting existing water rights, maintaining reasonably stable groundwater levels, and preserving the public welfare, safety and health can be fulfilled. Now would be a good time for Oregon’s leaders to take action.
References
Cook, Emily Cureton, Race to the bottom: how big business took over Oregon’s first protected aquifer. OPB, March 16, 2022.
Jaeger, W. K., Antle, J., Gingerich, S. B., & Bigelow, D. (2024). Advancing sustainable groundwater management with a hydro‐economic system model: Investigations in the Harney Basin, Oregon. Water Resources Research, 60(11).
New York times, America Is Using Up Its Groundwater Like There’s No Tomorrow. August 28, 2023. https://www.nytimes.com/interactive/2023/08/28/climate/groundwater-drying-climate-change.html
