||Vernal Pools are topographic depressions underlain by impermeable material that holds water during the spring time. These pools gradually shrink as water evaporates. Because of the soil moisture provided, vernal pool environments support unique plant communities and ecosystems including a number of rare and endangered species. Often these pools are ringed with wildflowers during the spring. As the pool shrinks, the wildflower bloom constricts with the shoreline, providing a succession of wildflower blooms.