Challenge


Ogden Dunes (1-mile along the shoreline) is located at the southern tip of Lake Michigan and subject to a significant 300-mile north fetch. The occurrence of extreme water levels and storms that exceeded a typical 100-Year set of conditions over Fall and Spring months in 2019 and 2020 resulted in critical shoreline erosion and damages to steel sheet piling vertical walls. The shoreline was also subject to severe wave overtopping damaging residential property lawns and producing flooding.

Solution


: A shoreline assessment study quantified the severity of damages and prioritized the repairs to be performed in three phases with construction cost estimates; in the process, it was recommended to select a resilient design condition to rebuild the shoreline. Some of the SSP walls failed and careful construction after stone filling and wall reinforcements was planned. Before joining GZA, Dan Veriotti was the Engineer of Record, Project Manager and lead Coastal Engineer for the implemented Phase I (approximately half a mile). GZA is now under contract for the planning of Phase II and II, with anticipated regulatory permitting, final design and construction in 2022/2023. The services provided included data collection (topographic and bathymetric survey, soil borings), Coastal analysis (water levels, offshore waves, wave transformation-computer modeling and desktop, overtopping rates), Design Development, regulatory permitting, preparation of construction plans, bid assistance, and periodic construction observations. The project also involved coordination (material preparations, presentations and field meetings) with National Park Service representatives in support of regulatory permitting. The project Phase I was constructed in spring 2021, with the remaining project areas to be constructed in the spring and summer 2022.

Benefit


The team led by Dan Veriotti, PE carefully planned and designed the proposed improvements providing shoreline protection and protection for residential properties.