After a stormy marriage that's lasted more than 40 years, Blaine's water system is seeking a divorce from neighboring Lexington.

Blaine says Lexington's water is too dirty for its customers. Lexington doesn't want the split, saying Blaine is trying to take control of a system they built together. The smaller city even accuses Blaine crews of secretly crossing city lines to sever water connections without permission.

Anoka District Judge Jenny Walker Jasper will give the two their day in court, scheduling a trial for April that could resolve a dispute that has simmered for decades.

The cities of Blaine and Lexington have shared their water since the 1970s through interconnected pipes and wells. For a few years the agreement seemed to help both sides, making sure water was available to new neighborhoods and firefighters near their shared border.

But since at least 1987, Blaine has tried, every so often, to separate its water system from its smaller neighbor to the east. Blaine City Council members and staff say that Lexington's untreated water is too hard, overloaded with calcium, alkaline and manganese. They want to install valves and bypasses that would keep Lexington's water out of Blaine. They would also put in meters to be able to accurately gauge any Blaine water used by Lexington.

Blaine sued Lexington last fall, asking a judge to order the smaller city to allow crews access to sever the system.

The separation would ensure that Blaine could provide fully treated and filtered water to its residents, the city argued in its complaint.

Lexington, meanwhile, says that the system cannot be so easily disconnected. The city argued in court filings that it has an equal ownership and right to the pipes, tanks and other infrastructure that was built with the understanding that it would serve both towns. The separation would not only reduce the water available to its residents and firefighters, but would cut off a few dozen Blaine homes from its own city's system, the city of Lexington said.

Blaine and Lexington city officials didn't return phone calls and emails seeking comment.

Blaine Mayor Tim Sanders told the Star Tribune shortly after filing the lawsuit in September 2022 that the city is not trying to be a difficult neighbor, but that the status quo can't continue.

The uneasy partnership has worked under a simple premise for decades. During the fall and winter, when water demand is at its lowest, Blaine provides all the water to Lexington's system. Then from May to October, when demand is high, Lexington starts pumping from its one well and shares the water with Blaine. The water going in and out of the two cities each year is believed to be roughly equal.

Since the original agreement, Blaine's population has exploded. It grew from a small rural community of a few thousand to a sprawling Minneapolis suburb with a population of about 70,000. Lexington, meanwhile has remained small, keeping a population of about 2,000 since the 1960s.

As Blaine has grown, so too has its water works. It recently spent about $40 million upgrading its water treatment system and installing new pumps to keep up with the city's growth. Lexington is using the same single well.

Blaine's elected officials broached the idea of severing the connection in the 1980s, 1990s and again in the 2000s. They were never able to reach an agreement with Lexington.

Lexington city officials have said that Blaine has tried to take over and make changes to the joint system without consulting or cooperating with Lexington.

In 2020, Blaine "secretly" sent crews into Lexington without notice or proper permits to close valves to try to separate the water, Lexington argued in court records. Lexington only discovered it happened when police officers stopped Blaine crews as they "illegally opened a street in Lexington" to try to repair a valve that they damaged during the operation.

Blaine's water operators have a recent history of acting without permission, Lexington argued.

In 2021, Blaine wrongfully pumped 380 million gallons of water from new wells without first getting state permits. The pumping caused dozens of nearby homes to lose water, a state investigation found.