Posted on November 30, 2017
By Phil Diehl, The San Diego Union-Tribune
A flurry of activity is underway to prepare for the long-awaited restoration of the San Elijo Lagoon, a nearly $120 million project planned for decades that starts in December.
Biologists are surveying birds, fish, water quality and other details of wildlife in the lagoon to collect baseline data before the dredging begins, said Doug Gibson, executive director and principal scientist of the San Elijo Lagoon Conservancy.
“That’s the big push right now, to lock on data that will be used to analyze the success of the project,” Gibson said.
Southern California’s coastal wetlands have largely disappeared. More than 50 percent and by some estimates as much as 90 percent of those estuaries, salt marshes, mudflats and similar tidal-region landscapes have been lost to development over the past 150 years.
San Elijo Lagoon, at the border of Solana Beach and Encinitas, is one of the best examples of that habitat and the challenges it faces. The 1,000-acre reserve is owned and managed by a partnership of the state, the county and the conservancy.
Lined with seven miles of trails used by joggers, dog walkers and school children on field trips, the lagoon has become an oasis where nearby residents can get a quick dose of nature and escape the noise, traffic and pavement that pervade so much of San Diego County. It’s also a safe haven for the native species of plants, birds, fish, and other wildlife that need the special habitat to breed and survive.
Gibson and his fellow biologists have been studying the lagoon’s biology for decades, in part to determine what needs to be done to save it.
The mouth of the lagoon is periodically bulldozed open to release stagnant water to the ocean and stave off environmental disaster, but that has never been enough to prevent the low-lying areas from slowly filling with silt and sediment. Water flow has long been restricted by the bridges that cross the channel for coastal Highway 101, the railroad, and Interstate 5.
The entire wetlands is overdue for extensive dredging and grading to restore and maintain tidal flows. And until now there was no money for that.
The solution turned out to be the $6 billion North Coast Corridor Program, an ambitious collection of transportation, environmental, and coastal access projects that will take shape over the next 30 years across the 27 miles from La Jolla to Oceanside. Overseen by the California Department of Transportation, the San Diego Association of Governments, and other federal, state and regional agencies, the program provides funding for a number of environmental projects, including the restoration of the San Elijo Lagoon.
The wetlands restoration, expected to take up to four years, is considered mitigation for the new bridges being built in the first phase of the corridor improvement program. Revenue from the TransNet sales tax paid by San Diego County residents will cover all the costs of the restoration, including the construction and long-term monitoring of the results.
Construction of the freeway and rail bridges are separate contracts that will cost a total $220 million, to be funded with a combination of federal, state and local money.
All the work is being done at the same time to minimize the negative effects on commuters, residents and wildlife, and to speed up the individual projects.
“It’s a great example of how work should be done,” said Arturo Jacobo, project manager for the California Department of Transportation, or Caltrans. “The end result is improved quality of life for the traveler, the community and the natural environment.”
Work on railroad and Interstate 5 bridges began a year ago. Completion of the freeway bridge — which will be wider with more carpool lanes — is expected in four years, while the railroad bridge — wider for a second set of tracks — should be finished in about 18 months. About 70 percent of the coastal railway has already been double-tracked between Union Station in San Diego and the Orange County line as part of the corridor improvement program. Eventually, the carpool lanes and double-tracking will extend the length of the county.
Also, the new bridges will be twice as long as the existing ones. Experts say that will go a long way to improve the health of the lagoon by placing less of a footprint in the channel and allowing more water to flow in and out.
The San Elijo Lagoon is more like an estuary than a lagoon, with a long, meandering channel where the river mixes with the ocean tides. Unlike other North County lagoons — Batiquitos, Agua Hedionda, and Buena Vista — which have been deeply dredged in the past, San Elijo has never been extensively excavated.
The main stream into the lagoon, Escondido Creek, is a seasonal waterway. Nearly dry most of the year, it swells with storm runoff during winter storms and carries sand, silt and sediment into the lagoon. Without the restoration, the lagoon would continue to shrink, eventually becoming a grassy field with a creek running through it.
“The muck is accumulating,” said Keith Greer, a principal regional planner for the San Diego Association of Governments, or SANDAG.
The goal of the restoration is to remove the built-up material and to leave the lagoon in a more manageable state, Greer said
“Those channels will be deeper and wider, and there will be more water,” he said.
Beach quality sand taken from the lagoon will be placed on the shore at Fletcher Cove and Cardiff, and some will be stockpiled offshore to be pumped back onto beaches in the future. The rest of the dredged material will be placed in a pit in the lagoon and capped with clean sand.
Visitors to the lagoon and people who drive over the site on the freeway will see a lot of bare ground for the next few years..
“It’s going to look kind of brutal for a while, until it’s all completed and the vegetation starts growing back,” Greer said. However, the payoff is the long-term health of the lagoon.
The restoration was first proposed in the 1990s, but the funding dried up before any work was done. That delay may turn out to be a good thing because it gave the conservancy more time to prepare a plan that’s best for the lagoon, said Gibson, the conservancy’s director.
“We’ve been developing this project for a long time, before any of us had heard anything about what was happening with I-5,” Gibson said. “Our goal all along was … a plan that the lagoon needed, not what somebody else needed for mitigation.”
The word “restoration” may not be the best way to describe the work planned for the lagoon, Gibson said, explaining that it’s more of an “enhancement.” The lagoon and the watershed around it have been so greatly altered by development that the area could never be restored to what it was 100 years ago, he said.
The goal is more of a “fairly natural” balance of wetlands habitats that allow native species to thrive, visitors to enjoy the lagoon, and the lagoon to adapt to the changes ahead.
“We’re enhancing now and for a future condition … like sea-level rise,” Gibson said. “It’s not a number that’s going to sit still; we are aiming for ranges.”
If done right, he said, the enhanced lagoon, or estuary, will be able to adapt to whatever’s ahead.
Source: The San Diego Union-Tribune
