Resilience in a coastal context

Tactics and interventions were discussed at a joint meeting of the five committees of the New York Rising Community Reconstruction Program that encompasses Nassau County’s south shore including Freeport.

At the December 10 meeting held at Norman Levy Lakeside School in Merrick, Arup Consultants asked the five committees representing Baldwin, Freeport, Merrick-Bellmore, Wantagh-Seaford and the Massapequas to consider a regional approach to addressing coastal flooding and water-related issues. “We are looking for cross collaboration because many of your issues and ways to address these issues are similar,” said Arup consultant Susan Ambrosini. Arup was hired by New York state to oversee the process by which each community may submit plans to help it build resiliency to future storms.

“You have great ideas and now we need to dive deeper into planning and into strategies for implementation,” said Betsy Mallow, Deputy Director for New York Rising.

Arup Consultants said the communities could consider a variety and combination of approaches to water issues including making hard infrastructure improvements, green infrastructure improvements and building up natural systems.

“But let’s look at the natural history [of the south shore of Long Island] and how that is related to vulnerability and resiliency,” said consultant Bill Dey. “There has been a dramatic development to the population in Nassau County since the 1930s when there were 400,000 people. Today there are 1.35 million people. The U.S. Geological Survey shows there is rapid development [since the 1930s] that filled in the wetlands which provide natural protection against storms.”

Additionally, “there has been severe erosion because of increased boat usage, an increase of nitrogen and phragmites [a type of sea grass] that have shallow roots and wash away,” he said.

Finally, sea level is rising. In the last 100 years, it rose one foot and will continue to do so. However Mr. Dey could not say if that was related to climate change. “We do know that there has been long term changes in the land sinking as a rebound from the glacier’s movement.”

Consultant Janine Witko said existing infrastructure, consisting of a separate sewer system and waste water system, did not have enough capacity to adequately accommodate all the types of flooding which occur along the south shore of Nassau County. “There are four types of flooding events – tidal fluctuations, sea level rise, surface runoff from rain and storms, and storm surge when there are extreme flooding events.”

During Sandy “we had the convergence of four events. The storm surge was ten feet; it was high tide. There is the issue of sea level rise and surface flooding with a lack of drainage,” she said.

Although there is no one solution, Ms.Witko said the region could consider storm sewer upgrades including tidal gates and check valves, as well as building new bulkheads, sea walls, and flood barriers. “But you need to consider the costs and ecology. The water has to go some place.”

Instead, green infrastructure and working with natural resources might provide a more eco-friendly approach to mitigation although these are considered more long term solutions that must be implemented on a regional level. “You must look at the entire watershed,” said the Arup consultant. Furthermore, these approaches have “their own set of challenges including interagency coordination to implement them and a shift in how municipalities operate. You also need to educate municipalities and people and get homeowners to participate.”

For example, in order to improve water quality and address storm water run off, more permeable paving systems could be put in place. Green infrastructure solutions also include creating stormwater ponds to capture rainwater in our parks. Bioswales – landscaped elements including plants and trees designed to remove silt and pollution – along our streets and highways and in public spaces can also improve water quality and deter flooding.

“Many green infrastructure projects can be latched on to capital improvement projects,” said the Arup consultant.

Natural resources – working with what is already in the Bay – might also improve resiliency, deter flooding and improve water quality which would in turn help increase eco-tourism and be a boon for the local fishing industry.

Bill Dey said the communities could consider tidal marsh restoration to help reduce storm surges and sea grass restoration projects to reduce storm surges and erosion.

Additionally, “there has been some exploration of an oyster reef restoration program which protects the marsh area and is under study by the Town of Hempstead Department of Conservation and Waterways,” said Mr. Dye. “However it would have impacts on waterway navigability.”