Tidal Flood Mitigation and Shoreline Protection

Cummins Cederberg is assisting the City with their Tidal Flooding Mitigation and Shoreline Protection project. The project consists of evaluating 22 areas, covering over 10,000 linear feet of shoreline, along the areas known as North and South Lake in the City of Hollywood. Each area will have specific solutions to address seasonal flooding challenges, which may entail the design and implementation of varied shoreline protection infrastructure such as of living shorelines, rock revetments, and bulkheads, to meet the requirements of the new Broward County ordinance. The scope of services includes biological resource surveys, above and below water engineering assessments, coastal and marine engineering, environmental permitting, bidding assistance, and construction administration.

Our team of marine biologists recently completed a benthic resource survey of the submerged lands adjacent to the 22 project areas. The survey was conducted using SCUBA during the seagrass growing season and identified important protected resources. Resources observed included shoal grass, paddle grass, and the threatened Johnson’s seagrass. This survey will inform project design to ensure impacts to these important resources are avoided and minimized to the maximum extent practicable and will support environmental permit applications. Biologists also assess the vegetation to identify protected and invasive vegetation in the 22 areas. This information will inform project design and support permit applications. Eradication of the exotic vegetation delineated during the survey may also provide ecological mitigation to offset unavoidable project impacts.

Upland and in-water engineering site inspections were recently performed at City owned shorelines in North Lake, South Lake, the southern end of West Lake, and along both sides of the ICW to evaluate conditions of existing seawalls and revetments. Tide gauges were deployed in North Lake, South Lake, and the Hollywood Marina to determine tidal prisms, lag time, and water level elevation differences between each lake and the ICW. This information will be utilized for design of tidal flood mitigation structures to protect from king tide and sea level rise flooding. This project will enable the City to mitigate the severe flooding that occurs during king tides in the neighborhoods surrounding North and South Lakes.