Four U.S. senators asked the Interior Department to delay settlement of a lawsuit filed by the Westlands Water District of California until they know whether it would continue sale of irrigation water to 156,000 acres of land not authorized by Congress to receive it, and whether the public will get a chance to comment on the proposal. Sens. William Proxmire (D-Wis.), Howard M. Metzenbaum (D-Ohio), Richard G. Lugar (R-Ind.) and Gordon J. Humphrey (R-N.H.) sent a letter to Interior Secretary Donald P. Hodel pointing out that the Reclamation Reform Act of 1982 requires that new and amended water contracts be open to public participation. An Interior Department spokesman declined to comment on the ground that he was unable to find anyone who had seen the letter.