The C-23 Canal Estuary Discharge Diversion Project includes a new seven-mile canal and a pump station with three pumps capable of moving approximately 112,000 gallons of water per minute, redirecting excess water from the C-23 Canal toward the C-44 Reservoir and Stormwater Treatment Area instead of the estuary. Gov. Ron DeSantis and the South Florida Water Management District marked the project's completion on September 9, after operational testing confirmed the system was ready for use.
During testing, the district said the system diverted approximately 4.8 billion gallons of water away from the St. Lucie Estuary. Longer-term monitoring will still be needed to determine the project's full effect on water quality.
The Project Targets More Than Water Volume
Large freshwater discharges create multiple problems for estuarine systems. Rapid changes in salinity can stress fish, oysters, seagrasses, and other species, and stormwater moving through developed or agricultural watersheds can carry nitrogen, phosphorus, sediment, and other pollutants downstream.
Reducing the volume of direct freshwater flows while routing water into infrastructure designed to store and treat it addresses both problems at once. Constructed wetlands do much of that treatment work, and the Army Corps of Engineers describes the broader Indian River Lagoon-South restoration program as an effort to reduce high-volume watershed discharges and nutrient loads while improving salinity and water quality, targeting sediment, phosphorus, and nitrogen entering the St. Lucie River Estuary and southern Indian River Lagoon.
One Piece of a Much Larger Restoration Program
This project was built and funded during the current Florida administration, but the underlying restoration effort stretches back decades, part of 25 years of Everglades restoration work already reshaping South Florida's water security. A 2004 project implementation report and environmental impact statement shaped the Indian River Lagoon-South project, which Congress authorized in the Water Resources Development Act of 2007 as part of the Comprehensive Everglades Restoration Plan.
C-23 and C-24 are significant pieces of a program that calls for roughly 130,000 acre-feet of new water storage across its reservoirs and treatment areas, plus another 30,000 acre-feet in natural storage, spanning Martin, St. Lucie, and surrounding counties. Kiewit received a $193 million initial construction contract from the Army Corps for the North Reservoir in 2024, and the water district has advanced construction of the South Reservoir separately. Once complete, the Army Corps estimates those components will add approximately 91,900 acre-feet of storage.
Water Infrastructure Is Becoming a Pollution-Control Strategy
Nutrient-control efforts have traditionally focused heavily on reducing pollution at its source, including agricultural runoff, wastewater discharges, and stormwater. Large restoration projects like this one add another layer, treating water infrastructure as natural capital rather than a sunk cost that changes when, where, and how water moves through a watershed.
Pollution entering the watershed does not disappear because of the C-23 project, and the risk of harmful discharges from the wider St. Lucie system remains real. What the project adds is operational flexibility to redirect C-23 flows toward storage and treatment infrastructure during high-flow periods, instead of letting untreated freshwater reach a sensitive estuarine environment. The watershed still faces multiple sources of nutrient pollution and freshwater stress and continues to draw legal scrutiny whenever development pressure collides with the broader Everglades restoration footprint.
Early Diversion Numbers Offer a First Test
The 4.8 billion gallons diverted during operational testing gives a real-world measure of how much water the system can redirect. Actual operations will depend on rainfall, canal levels, reservoir capacity, and water-management decisions.
A more meaningful measurement will come over time in whether the diversion reduces damaging high-flow events, improves salinity stability, and lowers nutrient loads. Florida now has another piece of infrastructure to manage C-23 flows before they reach the estuary, and the real test is how much difference it makes once the system has run through multiple wet seasons.
