The last impressive bloom of giant blue irises was in 2002. That September, Hurricane Lili briefly filled the preserve with several feet of brackish water. Irises are sensitive to salt water, which retards flowering or even kills the plants. Spring 2003 saw a great reduction in iris blooms. Although the springs of 2004 and 2005 encouraged some optimism that the fields of blossoms would eventually return, 2005's hurricanes caused another setback for the irises. Like Hurricane Lili, Hurricanes Katrina and Rita filled the preserve with several feet of brackish water. Although the water drained away in a few days, the effect of the water and decreased oxygen levels in the soil may have damaged the delicate irises. The residual salt left in the swamp may have damaged them even more. For months after Hurricane Rita there was no significant rain and so salt from the brackish water was not flushed out.