LINCOLN, Neb. (AP) — Helicopters will fly back and forth across parts of eastern Nebraska this spring to map out groundwater levels.

Several natural resource districts hired the helicopter to get a better idea of how much groundwater is available.

The low-level flights will cross parts of Butler, Saunders, Seward, Sarpy, Douglas, Lancaster, Cass, Otoe, Johnson, Nemaha, Richardson, Pawnee and Gage counties.

The helicopter will carry electronic instruments on a steel frame suspended 100 feet below the craft.