top of page
IMG_8118 (1).jpeg

St. Augustine Resilience Prepares Community for King Tides

By piloting low-cost, scalable sensors, St. Augustine is building a smarter flood monitoring network that will coordinate across Public Works, Emergency Management, and community residents

This is exactly what we needed and is very helpful as we push out our King Tide notifications. I actually received a King Tide text alert today. It definitely helps us be prepared for the higher tide events and prepare our community accordingly.

​

- Jessica Beach, Chief Resilience Officer

The Story

St. Augustine faces widespread nuisance flooding. For residents, this means closed streets and flooded cars. For the City, it means constant monitoring and reactive decision-making. With no local gauge, staff were manually translating NOAA forecasts to road elevations - a time-consuming process that often left gaps.

​

By deploying a Hohonu sensor on the bayfront, the Resilience Office gained real-time, street-level water data tied directly to local benchmarks. Within weeks, they were receiving live threshold alerts, validating forecasts against actual flood conditions, and using Hohonu's dashboard and analytics to back up King Tide messages with data and statistics the public could trust.

1.63 Feet

Peak water level added because of wind

4.1 Inches

Rainfall recorded during the same King Tide event

First Ever

Localized sensor record during King Tide event

Screenshot 2025-09-16 at 1.45.40 PM.png

Water levels exceeded thresholds during a September 2025 King Tide event. Observed water levels were 1.63 feet higher than predicted.

IMG_8117 (1).jpeg

Thresholds and alerts are now being optimized based on the sensor readings and widespread flooding that occurred throughout St. Augustine

Problem

  • Compound flooding from King Tides, nor’easters, and rainfall regularly causes street closures and vehicle damage.

  • No nearby NOAA tide gauge - distant stations often misrepresented local conditions.

  • Manual conversions from forecasts to NAVD88 and road elevations consumed staff time and risked errors.

  • Fragmented workflows across departments slowed messaging, road closures, and crew coordination.

Stakeholders

  • Resilience Office (Chief Resilience Officer) – Oversees King Tide notifications, resilience planning, and community communication.

  • Public Works & Utilities (Stormwater Operations) – Can use thresholds to manage closures, drainage operations, and field logistics.

  • Fire & Emergency Response – Gains real-time situational awareness during high tide and storm events.

  • Residents & Local Businesses – Benefit from trusted alerts and proactive flood messaging.

Outcomes

  • Faster public messaging – Threshold alerts backed up King Tide notifications with real-time, local data.

  • Operational efficiency – Crews could align work windows and road closures with actual tide and rainfall conditions.

  • Cross-department coordination – Enables coordination across Resilience, Public Works, and Emergency Management.

  • Community preparedness – Residents can sign up for King Tide text alerts and dashboard links, helping them avoid flooded streets.

  • Engineering value – Datum-tied records (NAVD88) support stormwater planning and design work.

Solution

  • Low-cost, easy-install sensors at the Marina gave the City localized, real-time water levels without relying on distant NOAA gauges.

  • Threshold-based alerts allowed staff to distinguish advisory vs. warning stages, improving road closures and public messaging.

  • Datum-tied data (NAVD88/MLLW) enabled direct comparison to road and storm inlet elevations for both operations and design work.

  • Intuitive dashboard provided a single source of truth across Resilience, Public Works, and Emergency Management.

  • Public-facing King Tide alerts and dashboard links gave residents timely, trusted information to prepare for flooding.

bottom of page