Little Lagoon Preservation Society News
Press Register July 21, 2010
Officials keep oil out of Little Lagoon but allow rising water to drain
Published: Wednesday, July 21, 2010, 5:00 AM
GULF SHORES, Ala. -- For the past two weeks an elaborate routine of moving huge mounds of sand with the high and low tides has been undertaken in an effort to drain Little Lagoon, which had been walled off from the Gulf of Mexico since early May and was beginning to spill over its banks.
Identified at the onset as one of the most critical water bodies on Alabama's coast to keep free of oil, the 2,225-acre lagoon, which serves as a nursery for all manner of aquatic species, has so far escaped contamination -- though not by chance.
Days after the Deepwater Horizon rig exploded and it became clear that oil was gushing unchecked into the Gulf of Mexico, threatening Alabama's beaches, work began taken to clog the pass by damming it with some 16,000 cubic yards of sand.
Aided by the natural accumulation of sand at the inlet's mouth that occurred when the ebb and flow into the lagoon was choked off, the barrier just north of the Ala. 182 bridge withstood June's onslaught of oil, as well as the surf churned up by Hurricane Alex. But on July 7, the pass was breached -- a development that no one has either been able to explain or take credit for.
Regardless how it happened, the cut came at a convenient time. The brackish lagoon, which is fed freshwater from nearby Lake Shelby and, scientists suspect, seeping groundwater, had risen by some estimates as much as a 18 inches above its normal levels. Yards along the lagoon's east end were beginning to flood and, more importantly, owners of homes with septic tanks were reporting seepage issues.
Since shortly after the breach, city officials -- along with contractors hired by the Alabama Department of Transportation, which maintains the pass --
Ryan Dezember/Press-Register. Though a berm built across Little Lagoon Pass was breached earlier this month, no oil has made it into the ecologically sensitive estuary and Gulf Shores officials have used the opening to drain the freshwater fed water body in recent weeks. A series of absorbent boom barriers and an engineered cut at the Gulf of Mexico that is blocked daily with mounded sand in advance of incoming tides have kept contaminants water out of the lagoon while letting excess water escape.
have taken advantage of a stretch of mild surf and a substantial decrease in incoming oil to drain the lagoon during outgoing tides. To ensure contaminated Gulf water doesn't permeate the lagoon, mounds of sand are piled into a channel that has been carved west through the sandy delta that has formed at the inlet's mouth.
Having the outflow course through the channel sideways into the Gulf keeps the lagoon from gushing through the pass and undermining the north berm and layers of absorbent boom that have been strung between the pass's jetties. It also makes everything easier to close up on short notice, said Noel Hand, the city's assistant public works director.
Though somewhat involved and labor intensive, the process has allowed the lagoon to drop 4 inches since July 12, yet remain free of contaminants.
"We've done such a good job of keeping that area clean, we're not going to do anything to change that," said Gulf Shores Mayor Robert Craft. "We're not going to let oil in there."
Members of the Little Lagoon Preservation Society, an environmental advocacy group, said they were pleased with the protection plan and have pitched in by providing data from weekly tests of the lagoon's salinity, turbidity, dissolved oxygen levels and bacteria surveys.
"So far, we really haven't seen anything terrible," member Dennis Hatfield said Tuesday night, during the organization's quarterly meeting. "We've seen dissolved oxygen drop, but not to alarming levels."
Bill Walton, an Auburn University professor who specializes in fisheries and aquaculture, told the group Tuesday night that although the lagoon's exchange with the Gulf has been maintained for the last few decades, the water body has historically undergone spells where it's closed off from the ocean. So, Walton said, it's safe to assume that the lagoon's inhabitants have adapted to cope with that isolation, and that closing the pass this summer won't do lasting harm.
"I would vote for that over getting oil in the lagoon," he said.