The Davenport City Council last night signed a long-term lease for its riverside stadium and agreed to renovate it. Aldermen inked a 15-year lease with the present tenant, Seventh Inning Stretch, which operates the Quad-City River Bandits baseball team. They also approved 12-point-five million dollars in renovations, ending a decade of controversy on that topic. Improvements will include a berm and movable floodwalls to flood-proof the place, new clubhouses, the addition of seats and suites and concessions on an open concourse. The playing surface also will be tiled for drainage. Most construction will take place after the 2003 season ends and before the 2004 season starts.