REVERE – Quick-acting city repair crews fixed a pipe that burst opposite 245 Walnut Ave. early Monday morning, sending water pouring onto Revere Beach Parkway.City workers repaired the break and cleared water from the Parkway in time for the morning commute, but the repairs underscore the challenges the city faces in replacing aging pipes and improving flood control.The city is starting a $750,000 repair job on Arcadia and Ellerton streets to reduce flooding to these low-lying streets off North Shore Road. Ward 5 City Councilor John Powers said Arcadia residents have sought flood relief from the city for years.”We’ll be tripling drainage capacity down there,” Powers said.Sherman Street residents have been seeking similar relief since last August when a pump failed during heavy rainfall and city workers were not alerted to rising water and sewage overflows on Sherman.A city plan to clean and upgrade flood prevention pumps includes a new alarm warning system for the Sherman Street pump.Mayor Thomas Ambrosino referred to the Arcadia project when he assured Sherman Street residents that their flooding problems would be addressed. He warned the two-dozen homeowners that permanent Sherman Street drainage improvements could take years to plan and pay for.Councilors are also seeking city officials’ recommendations for improving drainage on Asti and Tuscano avenues and Eastern and Tapley avenues and Gore Road.The city made major drainage improvements near the commuter rail tracks after a culvert collapsed in 2007 near the Rumney Marsh Academy construction site.The collapse posed major problems for the city because the 24-inch wide line carried sewage from the eastern side of Revere, including Point of Pines, to pipe connections along Legion Highway.A company specializing in underground drain work laid temporary drain lines and installed pumps while engineers sketched out a plan for rebuilding the culvert.Contractors think the culvert was built on top of wood timbers and other debris and gradually sunk under its own weight into the unstable material.