A prolonged drought, looming environmental rules and shortcomings in the incentives for building new power plants could cause even more problems with Texas’ electric grid in the next year. A number of Texas power plants may need to cut back operations or shut down completely if the state’s severe drought continues into the fall, as water levels in many plant cooling reservoirs continue to drop, said Kent Saathoff, vice president of system planning and operations for the Electric Reliability Council of Texas. Although a municipal utility provides electricity in San Antonio, it is part of ERCOT, so high power demand, conservation advisories and potential rolling blackouts affect its electric customers along with others in the state. In July the Environmental Protection Agency issued the final version of its Cross-State Air Pollution Rules, which require reductions in nitrogen oxide, sulfur dioxide and particulate emissions that cross state lines and contribute to ground-level ozone. The Railroad Commission of Texas, which oversees lignite mining operations in Texas, on Tuesday asked Attorney General Greg Abbott to sue the EPA over the rule, saying it fails to take into account economic effects and could harm both the lignite coal industry and power grid reliability.