A developer is trying to figure out how to build 522 homes here without disturbing a 600-foot-long vernal pool that is wet only during rainy season months.
Found primarily on flat land, vernal pools support a number of single- and multiple-cell organisms and vegetation not found elsewhere, according to state biologists.
In 1992, the city approved the development proposed by Lennar Communities. The company, however, needs the approval of the California Fish and Game Department before building near the vernal pool just north of Tierra Rejada Road and east of California 23.
Debbie Rosenthal, an attorney for the Mission Viejo-based company, said in a few weeks the firm will have an idea how the pool can be protected. Larry Sitton, a Fish and Game Department biologist, said vernal pools are particularly threatened because the flat land surrounding them is easy to build on.
"They are important because they have developed over millions of years," Sitton said. "They have unique vegetation and animal life on them."