PORTLAND — The Portland Water District wants to increase rates 1.9 percent, which would add about 32 cents to residential water bills.

The district has filed a request to raise the rate with the Public Utilities Commission. A public hearing is scheduled for March 14.

The water district increased rates in 2009 by 6.6 percent and also in 2006, 2007 and 2008, by 3.6 percent. Before that, rates had not increased in 12 years, according to the district website.

In a news release, the district said the increase is needed to fund system improvements. It would take effect May 1.

Waste-water fees are not included in the proposed increase.

The public hearing is at 6:30 p.m. at the Jeff P. Nixon Development Center, 225 Douglass St.

Portland Water District is a nonprofit, quasi-municipal agency. It serves nearly 200,000 people – 50,000 customers – in 11 greater Portland communities, delivering water service to Falmouth, Raymond, Scarborough, South Portland, Standish, and Windham, and both water and waste-water service to Cape Elizabeth, Cumberland, Gorham, Portland and Westbrook.