Protecting Groundwater Resources is Critical for Oregon’s Environment and People

By WaterWatch Staff  |  April 5, 2022  |  Instream

Groundwater provides a myriad of irreplaceable ecological benefits and is the sole source of drinking water for nearly one in four Oregonians.

WaterWatch has a long history of working to ensure that Oregon’s management of groundwater preserves the vital role of this resource in maintaining streamflows, springs and wetlands. This work has intensified in recent years as climate change and drought elevate the importance of groundwater as a buffer while simultaneously driving increased demand for groundwater in many parts of Oregon and as aquifer levels have declined from over-pumping.

Groundwater — What is It?

Oregon’s water code defines groundwater as “any water, except capillary moisture, beneath the land surface or beneath the bed of any stream, lake, reservoir or other body of surface water within the boundaries of this state, whatever may be the geological formation or structure in which such water stands, flows, percolates or otherwise moves,” according to ORS 537.515(5). Groundwater is just that — water in the ground.

Some groundwater in Oregon has been stored underground for many thousands of years and is recharged very slowly, if at all. In other places, groundwater is recharged more rapidly — for example, from each year’s melting Cascade Mountains snowpack. The amount of water that can be stored in the ground in any given place is highly dependent on geology. Many parts of Oregon have volcanic geology that often can store large volumes of groundwater. In some areas, geology limits the ability of rocks to store groundwater. Groundwater pumping that exceeds recharge will cause groundwater levels to drop; in areas with little recharge and very old groundwater, this is essentially mining of fossil water.

Groundwater-dependent ecosystems are ecosystems supported by groundwater. Where groundwater meets the surface, it provides cold, clean water vital to springs, wetlands, lakes, and rivers across Oregon. Streamflows in many rivers in Oregon, including the Deschutes, Metolius, Crooked, Klamath, Wood, Donner und Blitzen, and McKenzie, among others, are supported by groundwater inputs. A stunning example is Metolius Springs, where emerging groundwater creates the headwaters of the Metolius River, which in turn provides an important source of cold water to the Deschutes River. Certain wetlands and lakes also rely on groundwater. For instance, on the Malheur National Wildlife Refuge, groundwater supports wetlands relied upon by migratory waterfowl and an important lake that is home to many shorebirds, a unique type of speckled dace and a rare crayfish.

Not only do many plants, fish and wildlife depend on groundwater after it reaches the surface, some plants survive by tapping groundwater while it’s still underground. These plants can provide important riparian and upland habitat. Cold water refugia are also groundwater-dependent ecosystems critical to rivers and fish. Groundwater flowing into rivers and streams creates pockets of cold water that provide refugia for salmon, steelhead and other aquatic species from high water temperatures that can stress — and even be lethal — to fish. Climate change and increasing drought makes maintaining these cold water refugia more important than ever.

Drinking Water

In addition to its ecological importance, groundwater supports people across Oregon who rely on it for drinking water and domestic needs. The Oregon Health Authority reports nearly 23 percent of Oregonians rely solely on a domestic or private well for drinking water, while an estimated 70 percent rely in part on groundwater for drinking. Reliance on personal domestic wells is especially prevalent in rural Oregon.

Impacts of Declining Groundwater Levels

When groundwater tables drop too far, typically from over-pumping for irrigation, the groundwater can no longer flow to the surface to support springs, wetlands, lakes and rivers, and the fish and wildlife that rely upon them. Groundwater levels can also drop too low for plant roots to reach. Additionally, dropping groundwater levels cause immense problems for people who rely on wells for drinking water, particularly in rural Oregon. Excessive declines can dry up wells and require well deepening, which can be cost prohibitive and allow water quality problems present at deeper levels to impact drinking water quality. Improving groundwater management in Oregon helps preserve groundwater-dependent ecosystems and drinking water reliability for rural Oregon. This work is increasingly critical in our climate-changed world.

Groundwater Management in Oregon — The Law v. Reality

Oregon adopted a forward-looking Ground Water Act in 1955, which requires sustainable groundwater management. Unfortunately, Oregon’s groundwater management has fallen short of the Act’s provisions, resulting in declining groundwater levels caused by over-pumping of groundwater in many parts of the state. In Oregon, “[a]ll water within the state from all sources of water supply belongs to the public,” and this includes groundwater. However, when Oregon first adopted its water code in 1909, it focused on surface water. The code generally required anyone seeking to use surface water, for example, by diverting water from a river, to first get a water right from the state.

There were few efforts at state management of groundwater after adoption of the 1909 Water Code until 1955, when Oregon adopted its prescient Ground Water Act. Much has changed since 1955 — including ‘groundwater’ now being one word — but the Act’s forward-looking roadmap for sustainable groundwater management is more important and relevant than ever.

The Act requires that, subject to some exemptions, anyone who wants to use groundwater must get a water permit from the state. Importantly, several types of groundwater use in Oregon are exempt from permit requirements, with the majority of exempt use being domestic use and watering a lawn or non-commercial garden up to one-half acre at a rural residence. To lawfully use groundwater for non-exempt uses, such as irrigation for commercial agriculture, which accounts for the vast majority of groundwater use by volume, a permit is required.

According to the 1955 Ground Water Act, Oregon may only issue a new groundwater permit after finding that the use will “preserve the public welfare, safety and health.” This is where the act excels. It contains several key provisions aimed at ensuring that Oregon manages groundwater sustainably, including requirements that:

  • Groundwater pumping may only be allowed if the pumping is within the capacity of the resource.
  • The state determines and maintains reasonably stable groundwater levels.
  • Adequate and safe supplies of groundwater for human consumption are assured.

Oregon is also required to find that water is actually available for the proposed use before issuing a groundwater permit. By rule, this means that in the relevant aquifer, the cumulative groundwater pumping allowed by all existing water rights cannot exceed the average annual recharge to the groundwater source over the period of record. In other words, Oregon may only issue a new groundwater permit if existing permits are not using up the amount of average annual recharge. Oregon also may not issue a new groundwater permit if the new pumping would further deplete an already over-appropriated surface water, such as a stream or river, by depriving it of groundwater that would have otherwise flowed into that surface water.

Unfortunately, Oregon issued too many groundwater permits in many parts of the state, resulting in excessive groundwater pumping that has created crises for communities and ecosystems, including in the Umatilla Basin, Harney Basin, Klamath Basin and elsewhere.

Recent analysis by the Oregon Water Resources Department (WRD) shows the state is continuing to issue new groundwater permits in many areas where aquifers are in decline. This is antithetical to the Ground Water Act — and the practice must be reversed.

This WaterWatch staff article originally appeared in the April 2022 edition of WaterWatch’s Instream newsletter.