After unanimously approving a water and sewer rate increase, city councillors last night called for increased water conservation in Cambridge.

Although councillors said they had no choice but to approve the higher "block rate" fees, many urged that citizens look for ways to save water.

Councillors urged the formation of a citywide water conservation program, possibly funded by federal aid.

Councillors said Cambridge should adopt a vigorous conservation campaign involving officials from several city departments. "I think that there's only so much you can do by sending out flyers," said Councillor Francis H. Duehay '55. "There's nothing like an army of people who would take this message individually to each citizen."

But while increased conservation will lower water costs for individuals, it will not translate into decreased expenditures for the city, according to Vice Mayor Edward N. Cyr. "We will not save money by conserving," he said.

The water rate is based on the amount of money necessary to pay for the maintenance of Cambridge's treatment and sewage plants and personnel. These costs are fixed, no matter how much water is used, according to Duehay.

Water rates will increase 7.5 percent this year, while sewer rates will rise 37.8 percent.

The Cambridge Finance Department estimates the new rates will translate into approximately an $85 increase in annual water costs for the average single family home.

Councillor William H. Walsh said that if the cost of water continues to rise, the city could soon see water rates as high as property tax rates.

Duehay said local government must fight to recapture federal aid for water projects, or the cost burden will continue to fall heavily on the local taxpayer.

The steady increase of water rates over the past few years is a result of a decline in federal funding for water and sewage projects, according to Duehay.