A historic city fountain is set to spout again, perhaps as early as this morning.

After a rainy weekend and with fresh memories of a steam pipe’s deadly eruption in Midtown, Mayor Bloomberg is today likely to make an announcement in celebration of water: that for the fourth time in its history, the geyser-like plumes of the Central Park Reservoir’s fountain will rise.

The 60-foot fountain first shot forth in 1917 to celebrate the completion of the Ashokan Reservoir, the Catskill water supply’s newly built addition. Four jets could soon again jut forth into the summer morning sky to the joy of joggers, tourists, and residents.

The fountain sits 38 feet below the surface of the reservoir, which runs between 86th and 96th streets in Central Park and is named for a former first lady, Jacqueline Kennedy Onassis.

The fountain was closed soon after it opened in 1917, because nearby walkers complained of getting wet.

The underground nozzles were located and the fountain next spouted in 1998, after the completion of the first stage of city water tunnel no. 3. The ceremony, presided over by Mayor Giuliani, honored workers who had died over the years in tunnel construction. According to the New York Times, the fountain was turned off months later due to a drought.

The reservoir fountain, which is gravity driven, next spouted in 2003 to celebrate the 150th anniversary of Central Park.

The New York Sun’s architecture critic, James Gardner, said the reservoir was conceived as the unofficial center of the park. “It’s the biggest open expanse in the park and perhaps on the entire island of Manhattan.” He said the reservoir was “sort of like an intra-island ocean. It’s the closest thing we have to a large body of water in the middle of Manhattan and if you have a bit of imagination, it can function as the metaphorical equivalent of that immensity that people attribute to the sea or the ocean. We don’t quite have the Atlantic Ocean on Manhattan island, but this will do for us.”

A tour guide who runs Joyce Gold History Tours of New York, Joyce Gold, told The New York Sun that in 1842 some New Yorkers got indoor plumbing for the first time, and for that they built a receiving reservoir in Central Park. When Frederick Law Olsted and Calvert Vaux later designed Central Park, she said, they did not want that reservoir there because it had straight lines and they felt that in nature there are no straight lines. So, they built the present reservoir farther north, and where the old reservoir had been situated is now the Great Lawn. Ms. Gold said the reservoir is no longer used for the city’s water.

Anne Canty, a spokeswoman for the Department of Environmental Protection, which oversees the fountain, did not return calls yesterday, and the mayor’s press office declined to comment.