The Ridgewood Savings Bank held a grand opening Tuesday for its new branch in Williamsbridge. The opening, sponsored by the New York State Department of Banking, comes as a relief to many residents who say there are not many banks in the area. The state has declared Williamsbridge a Banking Development District for its lack of financial institutions. Residents say they often have to rely on ATMs and check cashing services. Officials at the bank say the branch will also work to increase home ownership in the Bronx community through expanded mortgage lending.