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County resilience official outlines modeling that supports higher seawalls, pumps and $20–$30 billion regional price tag
Summary
Broward County deputy director Jennifer Dorado told Lighthouse Point planners the countyused integrated modeling that combines sea-level rise, storm surge and rainfall intensification to recommend a tiered approach (5-foot seawalls plus green infrastructure to a possible 7-foot standard with pumps). She said countywide Tier 1/2 costs are roughly $20to$30 billion and urged municipal coordination on sequencing and funding.
Jennifer Dorado, deputy director and chief resilience officer for Broward County, told the Lighthouse Point Planning and Zoning Board on Sept. 3 that the countyis using an integrated model that combines sea-level rise, storm surge and rainfall intensification to guide infrastructure and land-use planning.
"We're using a 40-inch sea-level rise projection by 2070 — the NOAA intermediate-high scenario — as a planning basis," Dorado said, noting the county applies that projection in long-range capital planning and vulnerability mapping. She said the countytranslated modeling results into economic outcomes and infrastructure packages intended to reduce average annual losses.
Dorado described a two-tier approach the county modeled. Tier 1 assumes upgrading seawalls to a 5-foot NAVD finished-floor/seawall standard and broad green-infrastructure and storage improvements; Tier 2 (and the more extreme scenarios) contemplates higher seawall elevations — the county modeled 7 feet NAVD — coupled with additional pumps and active water management on the landward side of seawalls.
"Once you have 7-foot seawalls in place, almost without debate you need an additional set of investments, which is more pumps on the backsides of those seawalls," Dorado said, explaining the need to manage rainfall that would otherwise accumulate behind taller barriers.
Board members asked whether the modeling explicitly balanced seawall costs against pumping and storage. Dorado said the project ran sensitivity analyses across dozens of scenarios and optimized green-infrastructure siting and storage volume geographically, but it did not model the fine-grained engineering details (for example, exact pump sizing) at the parcel level.
She said the county is producing city-level deliverables: "When the project is in its final production with the deliverables, you'll have that breakdown by city," Dorado said. She also confirmed the countyhas begun converting modeled risk reductions into economic metrics and that the most recent memo places regionwide Tier 1 and Tier 2 implementation on the order of $20to$30 billion, a figure the county is revising to better reflect contingencies.
Dorado described the county's authority and role: her office is part of Broward County's Resilient Environment Department, which provides countywide land-use guidance, water-resource planning and technical support, and can establish comprehensive-plan and land-use plan tools that set obligations for municipal participation.
On funding and sequencing, Dorado said the county will pursue a mix of tools — grants, surtax measures, publicprivate partnerships and targeted programs — and will coordinate with municipal leadership through resilience roundtables and other forums.
Board members pressed on policy implications for Lighthouse Point, including whether a local ordinance requiring 5-foot seawalls by 2035 and 7-foot seawalls by 2050 would materially reduce risk through midcentury. Dorado said a 5-foot standard addresses higher-frequency surge and roughly two feet of sea-level rise for planning to 2070, while a 7-foot wall modeled with accompanying pumps offers substantially higher protection for the 20502070 timeframe, though extreme events still pose evacuation-level risk.
Dorado cautioned that retaining walls behind seawalls were not modeled as a substitute for consistent coastal barriers and that rising groundwater reduces subsurface storage capacity. "We've accounted for the change in the groundwater table that occurs with sea-level rise," she said, adding that drainage wells and aquifer injection strategies have limitations in South Florida.
The county presentation will be reviewed at upcoming municipal resilience roundtables and provided as public-facing modeling outputs. Dorado said the county will continue to refine city-level deliverables and cost estimates and expects more detailed engineering guidance to come as cities define project-level sites and priorities.
What happens next: the county will continue municipal-level briefings and provide the deliverables and supporting memos that will allow Lighthouse Point staff and the City Commission to refine local code and financing strategies.
