Jax Storm Resiliency Committee Calls For Drainage Improvements, Wetlands Protection

Jun 10, 2019

At its final meeting on Friday, Jacksonville’s Storm Resiliency Committee recommended the city take steps to protect wetlands.

The members of the Storm Resiliency and Infrastructure Development Review Committee voted unanimously to propose an ordinance requiring developments to be an average of 25 feet and a minimum of 15 feet from wetlands, whether or not those developments are determined to have an impact on the wetlands.

Wetlands are areas of land saturated with water found along waterways and in floodplains.

Wetland buffer zone
Credit City of Jacksonville

The city’s current comprehensive plan doesn’t require an average buffer distance, just a minimum of 15 feet. Local buffer requirements are common in Florida to provide water quality and habitat protection.

Wetlands in the St. Johns River watershed absorb more than 2,400 metric tons of phosphorous and nearly 80,000 metric tons of nitrogen each year, according to a 2018 paper in the journal Wetlands Ecology and Management. Removing a similar amount of nitrogen at a wastewater treatment plant could cost as much as $150 billion dollars a year.

Excess nitrogen and phosphorous in Florida’s waterways is considered one of the main drivers of harmful algal blooms.

Related: Algal Blooms Reported Throughout Lower Basin Of St. Johns River

Wetlands and other coastal ecosystems also help reduce inland flooding during storm surge events. Studies suggest wetlands can reduce flood damage by as much as 30%.

Wetlands also absorb and sequester carbon dioxide, the main greenhouse gas contributing to climate change. The drainage and degradation of coastal wetlands causes that carbon dioxide to be released into the atmosphere.

Committee members hope the recommended wetlands buffer change will help address what they see as a disturbing trend in Duval County: Between 2000 and 2018, 6,246 wetland acres were lost — nearly double the amount lost in any other county in the St. Johns River Water Management District. During that same time frame, 4,754 acres were preserved, enhanced or created — fewer than in many counties of similar size.

Cumulative wetland impacts, restoration and preservation in the St. Johns River Water Management District.
Credit St. Johns River Water Management District

Jacksonville resiliency committee Chair Sam Mousa said there need to be consequences if people don’t follow these new regulations, if they’re enacted.

“It needs to have teeth,” he said.

Mousa tasked Planning and Development Director Bill Killingsworth with looking into potential consequences. However, at the close of Friday’s meeting, committee members agreed that the scheduled final meeting on June 21 isn’t necessary and voted unanimously to cancel it.

However, Chair Mousa emphasized that this isn’t the end of the discussion on resiliency in Jacksonville. He pointed to the committee’s call for a contractor to help the city with stormwater management plan modeling, resiliency analysis and design.

Related: Jax Resiliency Committee To Recommend Building Regulations

“We are making provisions in our Capital Improvement Plan to fund the study,” he said. “We’re going to get a better handle on what we need to do to our existing infrastructure to become more resilient when it comes to storms and flooding.”

Meanwhile, previous committee proposals to improve drainage in Jacksonville are making progress.

The Maintenance of Drainage plan and other proposed changes to the city’s Land Development Procedures Manual have been approved and will be implemented as soon as they’re published.

Additionally, a bill (2019-375) establishing maximum impervious surface ratios throughout Jacksonville was introduced at the City Council’s May 28 meeting.

Related: Drainage Improvements Next Target For Jacksonville Storm Resiliency Committee

Impervious surfaces are areas of land that don’t allow rainwater to soak into the ground, including roads, buildings, housing developments and parking lots. Impervious surfaces can affect nearby rivers and streams’ water quality, flow and flooding risk.

In undeveloped, forested watersheds, most rainfall is absorbed into the soil, stored as groundwater and then slowly discharged into rivers and streams. Flooding is less frequent and severe under these conditions because most of the runoff from storms gets absorbed into the ground. In developed watersheds, more water flows into rivers and streams, and at a faster rate, increasing the likelihood and frequency of severe flooding.

Other Florida jurisdictions regulate the amount of impervious surface as a means of controlling the amount of stormwater runoff that must be collected, treated, transported and disposed of by the public stormwater management system.

Jacksonville does regulate maximum coverage by structures on each lot, but it doesn’t regulate add-ons like patios and decks, which increase impervious coverage. The city also doesn’t regulate impervious coverage at the subdivision level, which would take into account roads, parking lots, clubhouses and pool decks.

Public hearings on the bill will be held on June 25 and July 16. Final City Council consideration of the measure is scheduled for July 23.

Members of the committee will also present their report to the City Council during the Tuesday, June 25, meeting.

Brendan Rivers can be reached at brivers@wjct.org, 904-358-6396 or on Twitter at @BrendanRivers.