District, NRCS Improve Water Quality, Quantity in Idaho County

Improving water quality by closing drain wells is one focus of a cooperative project in Minidoka County.

"The idea is to close the drain wells and to use less water. The potential for contamination is reduced," said Dan Strickler, Minidoka Soil and Water Conservation District employee.

In the past, when a producer using gravity irrigation turned off his pump, bypass water continued to flow.

That excess water was channeled to a drain well, Strickler said.

The project is helping producers become more efficient by moving them from gravity irrigation to sprinkler irrigation that uses closed supply systems, Strickler said.

Results from tests of sample domestic wells show a clear trend, said Strickler.

Tests of sample domestic wells show:

-- 24 percent exceed Environmental Protection Agency standards for nitrate;

-- 31 percent exceed Idaho's groundwater standard for coliform bacteria; and

-- 81 percent contain detectable pesticides.

The Minidoka Land and Water Management Project is a joint effort of the conservation district, the Natural Resources Conservation Service, A&B Irrigation District, and other conservation partners.

"Although chemical and bacterial water quality degradation in domestic wells located near drain wells in the resource area has been documented, a direct causal linkage between drain wells and domestic well contamination has not been established," said Strickler.

How water moves through the aquifer is not understood, said Terry Edwards, an employee of the Natural Resources Conservation Service.

A domestic well near a drain well may have a lower contamination level than a domestic well further away, Edwards said.

Protecting the quantity of aquifer and surface water is another focus of the project, Strickler said.

Efficiency, the relationship between water pumped and water used, has moved from 40 percent to between 75 and 80 percent because water loss to evaporation and leakage has decreased, Strickler said.

A&B Irrigation District closed 11 drain wells in 1997. Of the original 79 drain wells, 15 remain open. Strickler said some will be left open for flood control.

Strickler and other representatives of the conservation district asked the county commissioners to include $3,500 for the district in next year's budget. That is the same level of funding the county has provided since 1995. The county budgeted $2,500 for the district in 1994.

The State contributes $5,000 to the district's budget.

The drain well project has been supported by Congressional appropriations totaling nearly $5 million since fiscal year 2000. Funding for fiscal year 2004 will be the last appropriation for the project, according to Stickler's presentation.

Forty additional producers were on the Natural Resource Conservation Service waiting list to participate in the drain well closure project, according to a project summary of accomplishments published March 2.

Story courtesy of South Idaho Press.