Two solar companies proposing large photovoltaic plants for the Carrizo Plain have reached an agreement that will prevent a lawsuit from three national environmental groups.

SunPower Corp. and First Solar have agreed to provide additional protections for endangered species in exchange for an agreement by the Sierra Club, Defenders of Wildlife and the Center for Biological Diversity not to legally challenge the solar plants.

The agreement does not affect a separate lawsuit filed by three local plaintiffs. North County Watch, Carrizo Commons and Michael Strobridge have filed suit to stop the SunPower project and plan to file a similar lawsuit by the end of the week challenging the First Solar project, said Susan Harvey, North County Watch’s president.

SunPower plans to build a 250-megawatt solar plant along the eastern edge of the Carrizo Plain, and First Solar plans a 550-megawatt plant to the west. Both projects have received county approval and are scheduled to begin construction in September.

Endangered species have been one of the biggest obstacles to both projects. The First Solar project affects the habitat of the San Joaquin kit fox, while the SunPower project affects giant kangaroo rats.

The solar companies agreed to these additional protections:

• Conservation of an additional 9,000 acres of land for a total of 26,000 acres, or about 40 square miles, as wildlife habitat. • Removal of 30 miles of fencing from the area to enhance wildlife movement.

• No use of rodenticides in either project.

• Additional financial contributions to San Luis Obispo County to conserve undeveloped lots in the California Valley subdivision.

“This agreement is a good reminder to plan smart from the start and avoid sensitive habitats altogether,” said David Graham-Caso with the Sierra Club. “There are plenty of places to put these solar plants where there are no sensitive habitats.”

Gov. Jerry Brown had been critical of efforts to stop the Carrizo Plain projects. His office facilitated negotiations to reach the settlement.

“This is another step in positioning California as the national leader in solar technology,” Brown said in a news release. “These projects and California’s overall renewable energy industry will help create hundreds of thousands of jobs.”