By Karen Hutchinson-Talaski
HERMISTON Without a proposed Critical Groundwater Area ordinance, some in the area believe Umatilla County could run out of water in the future.
Groundwater has declined over the years, say water experts from around the state.
Many people feel Oregon has all the water that it will ever need.
However, the water supply is limited.
With population growth and the increase in agriculture and other drains on water resources, water is being used much more rapidly than expected. Critical Groundwater Areas (CGA) were designated in Umatilla County as long ago as 1976.
Users of a groundwater resource are not isolated from one another. As one water user pumps water from the aquifer, water levels decline in response.
These declines cause lower water levels for other ground water users and compete with neighboring wells of the same source. The competition between wells is called "interference." Interference in the CGA has dropped many water tables to the point that well pumps require higher lift capacity (increasing costs by requiring pump upgrade and increased electricity use) or simply dry up (requiring costly drilling in order to deepen an existing well).
At issue is whether or not land owners will be able to develop their land for housing because of critical groundwater areas. The ordinance isn't meant to be a moratorium on all building within the CGA. It is an additional step to the Umatilla County Planning Department's permitting process for certain structures such are dwellings and other structures where exempt wells are allowed. An exempt well is one in which water is used for domestic purposes, doesn't pump more than 15,000 gallons of water and irrigates less than a half an acre of land.
If implemented, the proposed ordinance will require an additional step in the permit process. The step would include permission from the Oregon Water Resources Department (OWRD) and would include assurances that the water used would not be from a designated CGA source.
To understand the magnitude of the problems associated with CGAs, a review of specific examples are helpful. The following examples were taken from well hydrographs provided by the Oregon State Department of Water Resources.
An aquifer is a layer of rock or alluvial deposit which holds water. Gravel or alluvial aquifers refer to groundwater typically less than or equal to 100 feet beneath the ground. Basalt aquifers are groundwater greater than 100 feet beneath the ground's surface.
At Ordnance Gravel CGA, which was designated a CGA on April 4, 1976, shows that in 1955, it was 63 feet to the water table; in 2003, it is now 72 feet to the water table. The mid-70s saw the most significant drop in water levels when 45 operating wells dropped the aquifer water table to approximately 86 feet.
Ordnance Basalt CGA has two levels of well: shallow (less than 400 feet deep) and deep (greater than 400 feet deep). The shallow basalt wells are more readily recharged and less productive than the deeper wells. They are also somewhat unconfined aquifers while deep basalt wells are confined.
In 1970, shallow basalt wells were 90 to the water table; as of 1999, the wells were at the same level. However, the deep basalt wells are in trouble. In 1950, it was only 125 feet to the water table, in 2003, it is now 310 feet.
At Butter Creek at the Echo Junction Sub area, the water table was at zero in 1952. In 2003, the water table went down to 450 feet. That is a tremendous change over the years.
At the West Sub area, the water table was at 280 feet in 1968; in 2003, it is down to 570 feet. The East Sub area is another problem area. In 2002, the deepening of a well dropped the level of the test well 20 feet in one year. In 1957, the water table was at 50 feet, today it is at 170 feet.
At the Stage Gulch CGA, the water level was 50 feet above the land surface elevation. In 2003, it is down to 250 feet.
Although these figures do not include the entire aquifer, they still illustrate the problem Umatilla county is having with water. Some landowners have wells that are still providing adequate amounts of water; but for how long? The purpose of the ordinance is to protect the water landowners have now and in the future.
A public hearing will be held on October 23, 2003 at 7 p.m. at the Hermiston National Guard Amory regarding the adoption of the ordinance. The public is invited.