The process includes the use of a long reach excavator mounted on a barge with a roll off container for initial dewatering of the sediment. KRISTEN LIVENGOOD/Monroe County

On May 13, the U.S. Department of Agriculture’s Natural Resources Conservation Service (NRCS) extended the deadline for a grant to remove sediment lodged in Keys Canals by Hurricane Irma. The county now has through Aug. 18 to complete the sediment removal work.

“We got it in the nick of time,” said Monroe County’s Rhonda Haag, sustainability director, who said otherwise the work would have ended that day. 

The grant covers 10 canals — three in Marathon, five on Big Pine Key, and two in Islamorada. Two of the Marathon canals have already been completed in the area of Tingler Island near Sombrero Beach. Work has begun in Islamorada on canals 148 and 157.

The sediment removal is a little more involved than clearing marine debris from canals. Greg Tolphin of Adventure Environmental in Tavernier is overseeing the work. It begins by installing a boom connected to a curtain that extends to the bottom of the canal to prevent turbidity from entering open waters. 

“We have an excavator on a barge and the sediment goes into a dewatering box on the barge,” Tolpin said. “Then it’s transferred to another dewatering box on land before being trucked away.”

All the sediment is analyzed. Tolpin said the two Marathon canals tested clean and the fill labeled for “reuse.” 

The project is monitored by the Wood Environment to ensure all safety and environmental standards are met.

The sediment removal projects are just the tip of the iceberg when it comes to restoring canal water health in the Florida Keys. For example, the count is going back to the NRCS with a list of 244 more canals that were impacted by Hurricane Irma. Haag said the county has better documentation including sonar and underwater photos to submit. And, later this week, Haag will have the first meeting with state officials to begin work on restoring ALL the canals in the Florida Keys. Gov. Ron DeSantis announced the initiative during his visit to Marathon on April 17. The project is slated to span 10 years and the planning stages are being handled by the state Department of Economic Opportunity.

“This will be the third leg of the stool when it comes to Keys water quality,” Haag said. “The other two are stormwater and wastewater initiatives that are already complete.”

Haag also said the county has $100,000 in state Department of Environmental Protection grants to begin work on “plugged” canals. She said Islamorada and Marathon have been invited to submit proposals.

“There are 14 plugged canals in total,” she said.

 

• 100% initial marine debris clearing project (172 out of 172 canals)
• 20% complete with the approved sediment-removal canals (2 out of 10)
• 47% of budget spent ($21,500,000 of $45,821,212)

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