Thursday, April 07, 2016
SEA LEVEL RISE ON 4/11 CITY COMMISSION AGENDA
Report focuses on sea level rise impacts in St. Augustine
Posted: April 6, 2016 - 11:39pm | Updated: April 7, 2016 - 9:35am
Florida Resilient Communities Initiative report
By SHELDON GARDNER
As early as the year 2030, about 25 percent of St. Augustine’s land area — mostly salt marsh — could be flooded by 1 foot of sea level rise.
With 5 feet of sea level rise, close to 70 percent of the city’s land area would be flooded, according to a report by the University of Florida through the Florida Resilient Communities Initiative. A 5-foot sea level rise scenario is not projected to develop before 2085.
The report, for which the city budgeted $15,000, gathered information from existing studies and data to focus on how St. Augustine could be affected by sea level rise, what can be done and some available tools that can be used.
The report will be presented at Monday’s City Commission meeting, but it’s not the only thing the city is doing related to sea level rise.
“This is the first of many steps for us,” said Martha Graham, public works director. “We’ve already moved on to the next step.”
The next step includes working with the Florida Department of Economic Opportunity on a sea level rise vulnerability assessment, Graham said. The assessment will focus on the city’s infrastructure vulnerabilities to sea level rise and should be finished in December. Public meetings will be part of that process, she said.
The UF report, which is being finalized, gathered information already available from various sources into one document focused on St. Augustine, and it’s a way to start a conversation, said Reuben Franklin Jr., the city’s project engineer.
According to the report, “Accepted projections for tidal and storm surge levels for the Northeast Florida coast over the next 15 to 85 years suggest [sea level rise] from 0.25 – 6.67 feet (0.08 – 2.03 meters). At these levels the infrastructure, neighborhoods, and historic properties in the City of St. Augustine’s lower lying areas will be adversely affected. Upgrading the form and function of public infrastructure may improve the community’s resilience to the economic, environmental, and social disruptions that will likely accompany Northeast Florida [sea level rise].”
The sea level rise projections were mapped over the “mean higher high water,” which is an average of high tide numbers, according to the study.
The report looked at the effect of a sea level rise of 1, 3 and 5 feet on the city.
At 1 foot of “relative sea level rise,” the Castillo de San Marcos and other sites could be affected, including the Lincolnville Historic District, according to the report. The Castillo could be protected by the seawall, though.
At 3 feet, “Residential areas on the western and northern parts of Anastasia Island are significantly impacted. Impacts to the City’s stormwater facilities can also be seen under a three foot relative SLR scenario, including 18 lift stations and 437 manholes potentially submerged and continued inundation on the property of the Wastewater Treatment Facility,” according to the report.
Under a 5-foot rise, projected to happen “no earlier than 2085,” impacts are expected to the Cathedral Basilica in downtown St. Augustine as well as the St. Augustine Amphitheatre and other structures.
“While these impacts can appear troubling, given the earliest estimated time frame for those relative SLR amounts, the City has several decades to design and develop adaptive strategies,” the report said.
Steve Case 04/07/16 - 09:41 am 00Sea Level Rise
6.6 feet of Sea Level rise by 2100 comes to 24 mm/yr for the next 84 years. The current rate is about 3 mm/yr.
The obvious question to ask is, when will the rate of sea level rise begin to dramatically increase?
Steve Case - Milwaukee, WI