The City of Santa Cruz allocated $130,000 to continue researching long-term solutions to prevent flooding and damage to nearby properties at the San Lorenzo River Mouth Lagoon.
Shallowing of water at Main Beach has led to water levels rising at the river mouth, threatening nearby public and private property and restricting beach access for emergency services.
“In three to five years, we hope to relieve the pressure of the river without harm to local habitats and create a long-term plan,” said assistant to the City Manager Scott Collins. “The long-term plan we end up going with could be the same as the short term.”
The summer shoaling, or the increase in sand on the ocean floor, paired with changing ocean conditions causes high waters and floods the boardwalk basement and other adjacent buildings. Emergency service vehicles located on the west side have also lost access to the east side of the beach.
“We’re putting our heads together to maintain surface water elevation levels in the lagoon to prevent flooding,” said National Marine Fisheries Service biologist Jon Ambrose. “Something that doesn’t require breaching often results in bad water quality.”
Ambrose said the river mouth area is an “exceptional habitat for rearing” coho and steelhead salmon. Salmon that rear in the lagoon have a much higher chance of surviving the transition to the ocean due to greater access to food.
“As the sea level rises, this issue will become more acute,” Collins said. “We realize each dollar counts, but we want to get it right.”
Collins, who requested the funds from City Council on Oct. 14, continued the proposal from $45,000 which was allocated mid-year 2014. The allocated funds come from the city’s discretionary fund sources and “cover the studies and permitting costs to achieve an approved interim management plan.”
The groups working on the river mouth research include the California Coastal Commission, the National Oceanic and Atmospheric Association, the Army Corp of Engineers, the United States Fish and Wildlife Service, California Fish and Wildlife and the Water Quality Control Board.
The city funds attached to the project may be eligible for reimbursement of a projected 70 percent through the State Flood Control Subventions, a program providing financial assistance to local agencies cooperating in federally authorized flood control projects.
The interagency group is currently researching options to avoid physically breaching the levee at the mouth of the river, as it is unknown how the physical change will affect wildlife habitats in the area. The levee, also known as the San Lorenzo River Flood Control Project, was constructed by the Army Corps of Engineers in 1959 and has been repaired several times since then.
Although there is no definite solution to alleviate pressure at the San Lorenzo River Mouth, the interagency group plans to end its short-term solution in five years, giving the city time to develop and research alternatives for a long-term solution. City officials are working toward a fix to prevent further flooding and damage to nearby properties.