KCCI Investigates: Maffitt Reservoir's big year and how it'll be refilled

Maffitt Reservoir got called to duty in a big way this year.

A record-making way.

“Maffitt Reservoir reached unprecedented low levels this summer,” says Tami Madsen, the executive director of Central Iowa Water Works, the regional water authority.

The reservoir, built and filled in 1943-44, serves as a “savings account” for CIWW. The drought of 1934 led to its creation to ensure there was stored water.

It was pollutants that led to its record use this year.

“We had to use it earlier in the year to compensate for high nitrate levels, and we had to use it for longer,” says Madsen. “And we had to use it for longer.”

High levels of pollutants in source waters for drinking water also were a factor in the second straight summer with a lawn-watering ban.

The next step for the CIWW savings account is shoring up the balance.

“But right now, we are refilling it,” Madsen says, “and it’s more than likely going to return to normal levels in time for our next season.”

The only other time the reservoir got near that level was for maintenance.

“We manually refill Maffitt Reservoir by pumping low nitrate water into the reservoir while we’re out of peak demand season,” Madsen says.

Peak season is almost over. Lawn irrigation can take up to a third of daily water usage.