In the face of public outrage and county government opposition, officials of suburban Maryland's water authority said yesterday they are abandoning plans to charge customers more for using less water -- at least for now.

But they warned putting off action now could cost consumers even more next year.

The Washington Suburban Sanitary Commission, which provides water and sewer service to Montgomery and Prince George's counties, had voted unanimously last month to raise rates an average of $11.28 a household next year to make up for declining revenues it blamed on the soggy spring and summer seasons.

But commission officials said yesterday the three Prince George's commissioners have decided to vote to delay any increase at least until the next fiscal year, which begins July 1, 1980. Those three votes would be enough to block action by the six-member commission even if Montgomery County's members still favor the raise.

None of the three commissioners from Montgomery could be reached yesterday.

In the past, the commission has boasted of its successful water conservation campaigns. Published reports last month, which said the commission planned the rate increase to offset declining use, touched off a furor that convinced both county governments to actively oppose the commission action.

One Montgomery County official called it "paying for the rain."

The final vote on the increase is scheduled Dec. 12, but Johanna Norris, a Prince George's representative, said: "We're going to follow the advice of the counties to defer on this. I personally don't want to have any increase until the next fiscal year."

Both Prince George's County Executive Lawrence J. Hogan and the County Council asked the commission to cut back on costs rather than raise the average customer's annual bill of $145.60.

Commission General Manager Robert S. McGarry said yesterday. "We are cutting back in many areas to deal with the deficit, but without a mid-year rate increase, we expect next year's increase to be very substantial." m

The mid-year increase would have raised the average customer's water and sewer bill $11.28 to $156.88 for 80,000 gallons of water and would have made up the commission's projected $5.4 million deficit. The commissioners insisted the shortfall was due to decreased use of water for washing cars and watering lawns and not the result of the conservation campaign.

McGarry said the commission already has begun a series of cuts designed to reduce costs by more than $1 million , but the panel predicts delaying an increase now could result in a 36 percent rise in water bills next year.

That would push the average annual bill up about $58 more than this year to $204.

McGarry said he has ordered the postponent of all new construction contracts until May or June, a reduction in supplies of nearly $800,000 and the elimination of 61 people's jobs. The employes are to be reassigned, and some will be demoted.

The commission also decided over the weekend to eliminate its research division, close several public recreation areas on its property, reduce the frequency of inspection and lubrication of 24,000 fire hydrants in the two counties and cut back on service and maintenace positions.

Albert Joy, the commission's budget director, said that the cutbacks will redue the commission's deficit by about $1 million. The rest of the deficit would be covered by a $2.9 million surplus from sewer bills and shortterm rm borrowing.