U.S. District Judge Richard Matsch is to rule on the stormwater case against Colorado Springs, as closing arguments Monday wrapped up the trial launched by the U.S. Environmental Protection Agency and the state Department of Public Health and Environment.

Among other claims, the plaintiffs argued that the city’s stormwater program was inadequate at three sites: Indigo Ranch North, a development at Stetson Ridge; Star Ranch, a luxury homes community on the city’s southwest side; and MorningStar at Bear Creek, a senior living center. Arguments on those claims ended Sept. 7, Friday and Monday, respectively.

The lawsuit was filed in November 2016, seeking civil penalties for the alleged violations of the city’s federal stormwater permit. Pueblo County and the Lower Arkansas Valley Water Conservancy District later joined as plaintiffs.

The complaint says the city’s failure to properly operate and maintain stormwater facilities resulted in Fountain Creek and its tributaries being degraded, eroded and widened. Combined with surface runoff, those failures boosted sedimentation and sullied water quality, according to EPA audits in 2013 and 2015.

The runoff carries chemicals, sediment and other pollutants, erodes stream banks, destroys habitat for fish and other aquatic life and harms downstream communities, the audits found.

Pueblo County and the Lower Arkansas district cited increased E. coli levels, erosion and flooding as a result of Colorado Springs’ failure to corral stormwater effectively.

While the city’s potential liability is unclear, City Councilman Bill Murray said the civil damages could be significant.

“I’m absolutely concerned,” said Murray, who attended parts of the trial. “We are terribly unprepared for the results of this particular case.”

He said he’s not confident that Matsch will rule in the city’s favor, because city attorneys essentially admitted fault during the arbitration process. And more lawsuits could follow, he said.

“Unless we totally capitulate, like we did in Pueblo, and just throw our checkbook on the table,” Murray said. “Here’s my checkbook. Here’s my credit card. And it depends on how much blood from the turnip the EPA and the state want.”

The city agreed in 2016 to spend more than $460 million on stormwater projects over the next 20 years to placate Pueblo County, which long had borne the brunt of downstream stormwater damage from Fountain Creek.

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That pact came after the county threatened to withhold an essential 1041 permit needed for Colorado Springs Utilities to complete its $825 million Southern Delivery System. The project now funnels up to 50 million gallons of water a day from the Arkansas River to Colorado Springs, Fountain, Security and Pueblo West.

The litigation has been expensive, and more trials could be on the horizon, Mayor John Suthers told the council last week.

Hundreds of sites could be brought up in future lawsuits, said City Attorney Wynetta Massey.

Tuesday, Suthers reiterated his disappointment that the case was not settled before it went to trial, saying Colorado Springs “has expressed its willingness to remedy outstanding issues and is well on the way to creating the best stormwater program in Colorado.”

City voters last November agreed to resurrect stormwater fees, which are expected to raise about $17 million a year to help pay for the 71 projects outlined in the intergovernmental agreement with Pueblo County. Those projects are meant to mitigate floodwaters and pollutants flowing downstream.

The city had imposed stormwater fees in 2005 but defunded that enterprise in 2009. City officials saw the fees’ reinstatement as a proactive approach that might encourage the plaintiffs to settle the lawsuit.