SUPER alternatives offered

A consultant hired by the city supported the U.S. Army Corps of Engineers and county assessments of the degradation of Aliso Creek, but was at odds with the recommendations for restoring and cleaning it up.

The council voted unanimously after hearing the consultant’s report June 2 to spend another $1,000 to incorporate public comments, questions, recommendations and objectives expressed at the meeting into the report and send it, along with a copy of the minutes of the agenda item and a cover letter from mayor summarizing friendly suggestions, to the county and the corps.

“We agree with the county and the corps — the creek is eroding,” said consultant Nick Garrity from the firm of Philip Williams & Associates LTD. “However, we think there are alternatives to proposals that would better meet the city’s goals.”

PWA was hired to evaluate the county proposal and corps study in relationship to community goals and policies and to provide comments for the corps’ draft environmental report.

The county’s proposal is dubbed the SUPER Project, shorthand for Stabilization, Utility Protection and Environmental Restoration of the creek. It calls for the construction of 24 concrete grade control structures to stabilize the creek.

The project also includes proposals to fill the channel and consequent new flood plain, by up to almost 30 feet, to counter previous erosion; reconnect the former flood plain and allow fish to pass over the structures and a bridge; and regrading the banks in some areas.

However, Garrity opined that the structures would severely impact the habitat and the report questions the need for 24 structures. Half the number would do the job, he said, maybe even less and none under some scenarios.

“We commend them [PWA] for challenging conclusions and coming up with alternatives,” said Scott Sebastian, a member of the city’s Environmental Committee, who urged support for the PWA report.

“We need to figure out and synthesize a cohesive community program or say this is what issues we are interested in.”

Among the possible alternatives offered by PWA:

 Preserve the existing channel and flood plain with the use of a minimum number of 2-foot drop structures that would minimize impacts and reduce construction costs;

 Consider using non-grouted boulders for 2-foot drop structures that are likely to improve habitat and natural aesthetics;

 Allow flood plain sidewalls to erode, expanding the existing flood plain or regrading and planting them for stability;

 Moving infrastructure from the flood plain, reducing the need to protect it;

 Installation of boulder structures below a proposed structure and bridge to provide fish passage over the structures;

 Upstream measures to reduce urban stormwater runoff and pollutants, including best management practices and low impact development in the watershed;

 Lagoon restoration at the mouth of Aliso Creek, where a historic map suggests a lagoon may have once consisted of non-vegetated open water and sand shoals.

The city also asked the consultant to consider the potential of controlling storm water at the source to minimize the need for the structures.

Based on field reconnaissance, the report was not optimistic about that approach, although it is listed as an alternative.

“We would advise the city to have fairly modest expectations about using upstream stormwater control to reduce erosion downstream,” Garrity said.

The highly built-out nature of the Aliso Creek Watershed, dense development and relative lack of open space for infiltration and detention of water — ponds, so to speak — present substantial challenges for a storm water retrofit program that would significantly reduce erosion potential, according to the report.

Environmental Committee member Lisa Marks was disappointed about the advice to lower upstream development expectations.

“It’s discouraging,” she said.

However, Laguna Greenbelt Inc. President Elisabeth Brown had a suggestion.

“The parking lot at the Ziggurat (in Laguna Niguel) is never more than 40% full,” Brown said. “It could be a detention basin.

“Too much water is coming into that poor creek and natural detention reduces storm water.”

Mayor Pro Tem Elizabeth Pearson recommended soft pedaling aggressive demands on upstream communities.

“We need them to help pay for the project,” Pearson said. “Our city can’t pay for it by ourselves. We do want to make suggestions, but we don’t want to alienate them.”

The consultant’s original report ran to 33 pages, not including a description of the scope of work, the Aliso Creek Watershed Project List, planned water quality enhancements, and written and illustrated examples of the consultants’ stream and wetlands restoration projects.

A report revised after the meeting has been posted on www.lagunabeachcity.net/government/departments/waterquality/.