COLUMBUS JUNCTION, Iowa —The study of flooded basements in Columbus Junction has been completed, but solving the problems it uncovered might be an even bigger challenge for the community.

The study identified illegal connections to the sewer system as the most likely cause for much of the flooding, engineers with French-Reneker Associates of Fairfield, told the City Council during its regular meeting Wednesday.

Sump pump and perimeter drainage lines appeared to generate the most water into the sewer system, engineer John Meyer said. But he said he couldn’t explain why the flooding was not more widespread.

Complaints earlier this year focused on homes around the water tower and on Fulton Court. In some cases, the basement at one house was flooded while a neighbor’s basement was unaffected.

“I guess we’re puzzled. We understand the backup that occurred, but we’re puzzled why more people don’t have a problem,” Meyer said, adding the existing lines were large enough to handle the normal sewer load from the area.

Although the greatest source of water entering the sewer system is probably related to the sump pump and other illegal connections, Meyer said another problem area for the residents near the water tower might be overloading on the Springer Street sewer line.

Currently the Springer Street lift station discharges into the Springer Street line. During periods of heavy rainfall, the Springer Street line can quickly fill to capacity and lead to basement flooding at homes near the east end of the street.

To solve that problem, Meyer suggested running a new line from the lift station to a different sewer line to the north. That should ease the load on the Springer Street line and hopefully cut down on the basement flooding in that area.

The Council later approved moving forward with that project, with the city crew doing the work.

Finding a solution for the infiltrated water from illegal sewer connections would require the council to consider two options, Meyer said.

“It’s really boiling down to a house-to-house approach,” he said, explaining on-site inspections and televising of lines would be needed to establish where the illegal connections were located. Homeowners would need to cooperate with that work and Meyer said the city could develop either a carrot or a stick approach to get that cooperation.

Meyer said the city’s current ordinance allows it to enter homes for inspections and if those inspections showed illegal connections, the city could order the homeowners to disconnect from the sewer line. The other alternative would be to develop a program that would provide the owners with funding assistance as an incentive to removing the connections.

Mayor Dan Wilson said the city needed to resolve the issue.

“It’s time for us to move from the investigative stage to the let’s-get-something-done stage,” he told the council.

Council member Mark Huston suggested the city offer homeowners a 30-day amnesty to remove any illegal connections. He said the program could offer some type of assistance.

“If (the owners) don’t act during the amnesty, (the city could) go into the stronger enforcement phase.” he continued.

Meyer told the council any effort to remove the excess infiltration would also need to include Columbus City. He said there was a considerable amount of excess water coming into the Columbus Junction system from that community through its joint sewer system. Officials agreed there needed to be some control of Columbus City’s infiltration, but acknowledged the basement flooding problem had been occurring before Columbus City residents were added to the system, so that infiltration was likely not the main problem,.

Meyer and engineer Matt Walker said they would complete their final report and present it to the council before the end of the year. Council members indicated they would then begin considering which option to follow for removing illegal connections in the meantime.