Des Moines Water Works, in a brief filed with the Iowa Supreme Court this week, contends that it is time for the court to set aside any protection drainage districts have had against lawsuits.

“Drainage districts have historically enjoyed a broad immunity from suit, but this Court should critically examine the contours and limits of such immunity as applied here,” wrote the utility’s lawyers, a team from Dickinson, Mackaman, Tyler & Hagen P.C. “When the reason for a rule ends, so should the rule.”

Water Works sued Sac, Buena Vista and Calhoun counties over nitrate pollution from drainage districts that the counties run. The utility contends that the drainage districts, which are sending nitrate down the Raccoon River, a source of drinking water, should be regulated under the U.S. Clean Water Act. The utility also wants damage payments to offset Water Works customers’ payments to remove the nitrate before the water gets to taps.

The U.S. District Court in Sioux City asked the Iowa Supreme Court to consider several legal questions before the federal court rules on whether the drainage districts have immunity to damage claims. Lawyers for the drainage districts, a team from Belin McCormick P.C., expect to file briefs in the next two weeks. Agricultural officials have contended that the drainage districts have immunity, in part because they don’t have the power to stop the pollution from farms in the area.

The case is scheduled for trial beginning Aug. 8.

Water Works’ lawyers aren’t buying the drainage districts’ contention that they can’t be sued for damages.

“Drainage districts asked the District Court to dismiss (the utility’s) claims for damages and equitable relief set forth in a Complaint that alleges drainage district pollution jeopardizes the safety of the drinking water of at least 500,000 Iowans,” Water Works’ lawyers wrote. “Drainage districts sought dismissal based on a judicially created immunity doctrine uniquely available to drainage districts. They also asked the District Court to deny ‘takings’ and other constitutional claims made by (Water Works) on the grounds that (the utility) neither has constitutional rights, nor the right to assert them against the drainage districts.”

“The unqualified immunity that drainage districts have enjoyed for over 100 years is based on a foundation that makes no sense today, particularly in a water pollution case, and also violates the equal protection, due process, just compensation, and inalienable rights guarantees of the Iowa Constitution,” Water Works’ lawyers wrote. “Further, and without regard to the status of the immunity doctrine as it may apply to other claims, such doctrine does not defeat either of (Water Works’) claims for equitable relief or taking with just compensation.”

Also this week, the Environmental Law & Policy Center, a Chicago-based nonprofit with a Des Moines office, joined the fray with a friend of the court brief.

The group concluded that drainage district law does not give the drainage districts a “license to pollute” and urged the court to hear Water Works’ arguments both in favor of the Clean Water Act regulation and in support of damage payments.

“The defendants’ theory of unqualified immunity for drainage districts removes any incentive the drainage district has to help limit pollution and leads to severe consequences that fail to adequately account for public health and welfare as required by Iowa’s drainage district law,” the group wrote in its brief.

Water Works “has hovered on the cusp between public health crisis and public health catastrophe as it has been forced to deal with a constant barrage of nitrate pollution and new record highs of nitrate pollution seemingly every season,” the group added.

“The defendants’ theory of unqualified immunity gives drainage districts free rein to pollute. Unqualified immunity for drainage districts removes any incentive the drainage district has to help limit pollution and leads to severe consequences. The Court should find that the presumption of public benefit underlying unqualified immunity can be rebutted and give (Water Works) the opportunity to do so,” the policy center wrote.