While most hydrologists — those who study the science of water — agree that groundwater pumping can dry up surface flows, courts and legislatures haven’t turned that principle into law . . . Efforts to protect rivers from water pumping in the Legislature, all unsuccessful, date back to the time when Rose Mofford was governor back in the late 1980s, said Sandy Bahr, director of the Sierra Club’s Grand Canyon chapter. “There was a riparian task force. There have been bills that included limits on groundwater pumping within one-quarter mile of riparian areas. Those were defeated by cattle growers and others,” Bahr said. Just this year, a bill dealing with the ecological value of water failed to get a hearing. “We have consistently asked the state to recognize the connections between ground and surface water. Our laws violate the laws of physics,” Bahr said.