Life after the storm

How living shorelines can restore communities damaged by severe weather events

Since Superstorm Sandy devastated communities all over the state, storm resilience and shoreline restoration have become top priorities for shore towns and low-lying areas. But this process is difficult, largely because of limited resources and varying landscape challenges. Municipalities have to weigh parallel goals of repairing damage from past storms and strengthening infrastructure for future disasters, almost always with significant budget restrictions. It is not unheard of for a storm resiliency project to employ more short-term solutions due to financial constraints, even if doing so leads to greater damages and costs down the line. Meanwhile, the most efficient solutions may be untenable because of the physical setting limitations of a given town or city.

As a result, shoreline and storm protection projects can benefit greatly from innovative new methods that meet community needs while doing more with fewer resources. To this end, T&M Associates, has found success with a living shoreline model to combat erosion, restore and stabilize beaches, establish and strengthen natural habitats and protect existing infrastructure and homes, all while remaining cost-effective for municipalities. In the coming years we can expect to see living shorelines become more commonplace as an effective strategy for storm protection, flood mitigation and combatting shoreline erosion.

Previously this approach could only do so much within a narrow set of conditions.

Worth

The living shoreline model has existed for some time but has had limited application in certain landscapes. When faced with an exceptionally challenging project, T&M was able to incorporate some new elements that made it significantly more viable for a wider array of New Jersey shore habitats and communities. As the adage goes, necessity is the mother of invention. Little Egg Harbor Township and the Borough of Tuckerton had struggled to recover from Superstorm Sandy and years of shoreline erosion due to some unique landscape challenges in the waterfront areas of Iowa Court and South Green Street, including greater elevation and mean higher high water line and close proximity to residential areas that required additional protection. Using a traditional bulkhead, a popular and relatively inexpensive approach, would not adequately address wave action and could increase the risk of scouring, or shift risk to adjacent property owners.

To meet these challenges while also restoring lost habitats and maintaining the area’s natural beauty, we implemented several all new shore stabilization techniques into a living shoreline model. Typically, a living shoreline would be difficult to incorporate into a residential setting and to maintain at this greater elevation over time, while also allowing water to move into the area at controlled levels for natural habitat support.

To accommodate these limitations, we developed innovative new elements:

• Installation of a marsh sill set to the mean higher high water line (the average of the higher of the two high water heights of each tidal day), with an internal bulkhead for added protection against settlement over time
• Restoration and planting of nearly 1 acre of marsh
• Twice daily inundation of the marsh via notches in the internal sheeting, to support habitat health and growth
• Installation of 50,000 spat-on-shells on the marsh sill to establish an oyster habitat
• Beach replenishment and installation of a stone breakwater—a long, low, narrow structure set in the water near the coast to mitigate intense wave action

_{Some residential areas required additional protection such as Green Street. – T&M ASSOCIATES}

While these techniques seem complex, the results are clear. The project was completed in September 2019 and was a great success for the Little Egg Harbor and Tuckerton communities. Local marshes and wetlands were restored and natural ecosystems were strengthened to benefit fish and wildlife. Beaches were replenished and are protect from erosion by the in-water structures, while protecting homes and other vulnerable areas. And perhaps most importantly, the project was completed under budget.

Since the restoration of Iowa Court and South Green Street, this living shoreline model has received significant attention and praise, including in the American Council of Engineering Companies of New Jersey 2020 Engineering Excellence Awards, and the New Jersey Society of Municipal Engineers 2019 Project of the Year Awards. There is growing interest in this approach from municipalities up and down the Jersey Shore. Storm and flood damage is still a pressing threat to hundreds of towns and boroughs, and it is widely accepted that storms like Sandy will only become more frequent due to the effects of climate change. Thankfully, there is hope in innovation and creativity – with new approaches to living shorelines we can breathe life back into devastated beachfront communities and the natural ecosystems that support them.

Jason Worth is group manager at Middletown-based T&M Associates.

Source: njbiz