Coral Gables Tidal and Mangrove Sediment Elevation Study

 

Blue Road Tidal Gauge

Background

Coastal wetlands provide essential direct livelihood services to millions of people, as well as critical regulating services such as maintenance of water quality, protection from storms and erosion, and carbon sequestration. Measuring the vertical movement of the coastal wetland surface and its constituent processes, and relative local sea-level rise (SLR) is necessary to determine whether a wetland can keep pace with SLR.

Tidal data can assist in understanding localized flooding associated with king tide flooding and sea-level rise. These data are an important resource for hurricane preparations and for recreational use about boat clearance through rivers and canals.

 

Study Area

Four monitoring stations are being established: 2 tidal stations at Blue Road and Isla Dorada Boulevard bridges and 2 tidal and soil elevation monitoring sites in Matheson Hammock and a mangrove site near Coral Gables Marina.

Data Access

If you would like to access tidal station data for the Blue Road and Isla Dorada Boulevard bridges to find out what the clearance is under these bridges, please see real-time data link below.

<<CLICK HERE TO LINK TO DATA>>

How to Interpret These Data

The difference between the tidal depth and the bridge height is the boat clearance. Below are the heights for some of the City of Coral Gables bridges:

Prado Blvd Bridge 7.0 ft NAVD
Pisano Avenue Bridge 7.0 ft NAVD
Bird Road Bridge 7.5 ft NAVD
Blue Road West Bridge 7.5 ft NAVD
Blue Road East Bridge 7.5 ft NAVD = 9.85 ft relative height
Ponce DeLeon Blvd Bridge 7.5 ft NAVD
Red Road Bridge 7.5 ft NAVD
Red Road Ped Bridge 1 7.5 ft NAVD
Red Road Ped Bridge 2 7.5 ft NAVD
Biltmore Cart Path Bridges (5-9, 14, 17) 8.0 ft NAVD
Alhambra Bridge 9.5 ft NAVD
Lugo Avenue Bridge 9.5 ft NAVD

For Blue Road East Bridge, clearance = 9.85ft – tidal depth shown on data page. To check the tidal water level, go to the link above, select "Blue Road" under "Locations" on right panel and Select "depth" in options on the top panel.

For example, tidal depth on October 29, 2017 at 1112AM was 1.92ft. To calculate distance between the bottom of the bridge (relative height) and the tidal water surface below the bridge relative height, compute: 9.85ft – 1.92ft = 7.93ft. In this example, 7.93ft is the distance between the bottom of the bridge and the tidal water surface.

 

Soil elevation and tidal gauge set-up in a coastal mangrove (Figure courtesy of J.C. Lynch, U.S. N.P.S.)