IRVINE : Watering Hole Filled for the Birds
Ducks, geese and other migratory fowl again have a welcome pit stop on their southerly migration route as the Irvine Ranch Water District continues its fall ritual of creating huge ponds in the San Joaquin marsh.
For decades, a hunting club paid the water district to flood the ponds as a means of attracting migrating birds to the riparian area split by Campus Drive west of the UC Irvine. Irvine refused to renew the club’s hunting license in 1988, but the water district and the city decided to maintain the winter rest stop that the birds have become used to, said Peer A. Swan, president of the water district’s board of directors.
Each fall, the city mows down weeds in the ponds, and the water district uses natural ground water and reclaimed water from a sewage treatment plant to flood the 50 or so acres to a depth of about one foot, Swan said. Reclaimed water is highly treated waste water that the district supplies for landscape watering throughout Irvine.
The flooding operation, which started earlier this month, has already attracted at least 100 birds to the ponds, he said. The number of birds using them during the winter is estimated to be in the thousands.
Historically, the marsh was part of a larger, freshwater wetland that stretched from lower Newport Bay to Tustin. But development and siltation have cut off much of its water supply, so the ponds must be created artificially.
Biologists have said that unless the ponds continue to be flooded each fall, migratory birds on the Pacific Flyway will avoid the area permanently, Swan said.
Come spring, when the birds leave, the ponds are drained.
The only problem with the flooding in past years has been a temporary odor as the vegetation beneath the water decays, water district spokeswoman Joyce Wegner-Gwidt said. City and water district workers tried to remove as much vegetation as possible before the flooding began, but the odor problem still might be noticed by residents near the marsh, she said.