State officials say heavy rains in northern Iowa have overwhelmed many drinking water and wastewater systems.

Drinking water has been trucked in for residents of Rock Rapids. Customers of the Lyon and Sioux Rural Water System in northwest Iowa have been advised to boil their water. Bryon Whiting, an environmental specialist with the Iowa Department of Natural Resources, says it’s because the drinking water plant in Rock Rapids was inundated with water and has been shut down — and the rural water system in the area gets some of its water from Rock Rapids.

“Generally it’s uncommon to have systems that are completely flooded out because they anticipate this could happen,” Whiting says, “but when you get back-to-back rains, these things happen and when they do…first and foremost public health is the main interest here.”

Some areas of far northwest Iowa got heavy rain this weekend and another three to five inches of rain on Monday night.

“You know, having water is one thing,” Whiting says. “Having safe water is an entirely different issue.”

According to Whiting, rural Iowans who get their drinking water from a private well need to ensure surface water isn’t running into the well.

“That could introduce bacteria into their system,” Whiting says. “And, of course, they might want to protect it with some sand bags as well is if it looks like water’s running towards the well.”

The water plant in the town of Wahpeton, in Dickinson County, lost power, but the city is buying water from nearby Milford to meet demand and maintain pressure in the system. In Sioux City, sandbags have been placed around two of the wells in the town of Hawarden. A few customers of the Iowa Lakes Regional Water system in Clay County have been without water and officials say those customers should boil the water after service is restored.

At least 34 Iowa cities have discharged wastewater because those cities’ sewer systems and water treatement plants were overwhelmed by the intense rainfall. Nineteen livestock operations in Ida and Lyon Counties notified state officials because their manure storage basins overflowed due to the heavy rains.

Late Tuesday afternoon Governor Branstad declared “disaster emergencies” in five counties — Cedar, Lyon, Plymouth, Pocahontas and Sioux. It means state resources may be used in those areas to deal with the effects of the storms. More than a quarter of a million sandbags were dispatched to northwest Iowa and state-owned pumps were sent to Rock Rapids and George to try to reduce the water threat around critical infrastructure. The governor and the director of the Iowa Homeland Security and Emergency Management Department plan to personally survey damage in Rock Rapids and Rock Valley later today.