Irrigation & Backflow

Water demand increases sharply in the summer months largely because of irrigation.

Historically the City of Manhattan Water Treatment Plant experiences the greatest demand for water during the months of July and August.

Our goal is to spread water demand during the critical summer months. 

One way of achieving this goal is by adopting the odd and even irrigation system:

  • Even- numbered homes irrigate on Monday/Wednesday/Friday.
  • Odd numbered- homes irrigate on Tuesday/Thursday/Saturday.

The City of Manhattan tried to implement the odd/even system in the past, but unfortunately the majority of sprinkler systems in Manhattan continue to be scheduled on Mondays, Wednesdays and Fridays. This significantly increases water demands on those days and can place stress on the city's water system.

Please take the irrigation initiative by switching your irrigation schedule to Tuesday, Thursday, Saturday.

For more information, contact our Public Works department at (785) 587-4544 or download Take the Irrigation Initiative.

2022 average weekly water use during the months of July and August in 2022
Monthly Average Daily Water Use

Backflow Prevention

Irrigation systems are a common cross connection source. The city requires all irrigation systems in Manhattan to have a backflow preventer to reduce the likelihood of contamination of the public water supply. Backflow occurs when water in a distribution system flows in the opposite direction from what is normal. Hazards that require backflow preventers include fire sprinkler lines, lawn sprinklers, boilers and carbonated beverage dispensers. View more information about backflow prevention and cross connection.

Required Yearly Testing of Prevention Devices

While backflow prevention devices do a good job at protecting the water supply, they must be tested and maintained regularly to make sure they are in proper working order. The City requires yearly testing by a certified testing provider.

Testing providers can submit their test results to the City. To use this feature, testers must calling (785) 587-4544 or email this form: