Report: Sea levels in region could surge over 70 years

Sea levels around Long Island and New York City could rise by between 1 and 4 1/2 feet over the next 70 years, according to a report advising state and local governments to minimize damage to coastal property and natural resources by planning ahead.

The report predicted that rising oceans linked to climate change will worsen beach erosion, drown vulnerable marshes, imperil coastal infrastructure and increase flooding in low-lying areas such as the South Shore of Long Island.

"We're going to see septic systems in coastal zones flooding and being inundated on a regular basis, and that impacts water quality," said Nathan Woiwode for the Nature Conservancy, an environmental organization that contributed to the draft report released last week by the New York State Sea Level Rise Task Force.

The findings are intended as a blueprint to help lawmakers, government agencies and municipalities adapt to sea level change.

A final report will be submitted to the state legislature by the end of the year. Many of the findings were previewed last year as the task force toured the state, although meetings on Long Island were thinly attended.

"It's hard for the government and planners and the public to get their hands around this. But it really needs to be addressed," said Michael White of the Long Island Regional Planning Council.

Oceans are likely to rise at a faster rate over this century as they warm and expand, and ice caps and glaciers melt. The slow sinking of coastal land from geologic processes and human development along shorelines also contribute to sea level changes.

The report based predictions on scientific models incorporating a range of future greenhouse gas emissions. While precise forecasts are difficult given the complex interplay of climatic and geologic factors, "the outlook for our region is dramatic and will change the coast in fundamental ways," according to the report.

Some areas closest to sea level could end up permanently underwater while others will likely flood more frequently during storms, the report said. Rising seas may elevate the water table, swamping basements and cesspools, or lead to saltwater contamination of coastal drinking water supplies. Flooding would increase vulnerability of sewage treatment plants as well as roads and bridges along the coast, according to the report.

Led by the state Department of Environmental Conservation, the task force formed in 2007 to assess the state's vulnerability to sea level changes and explore ways to adapt.