Indian River Lagoon Council Board of Directors Meeting

Water Conditions Update

Deborah Drum, Manager Ecosystem Restoration & Management Division Engineering Department Friday, October 13, 2017 Water Management District-Wide Rainfall

September 2017

• September rainfall surpassed September average by 6.30” • District-wide, September rainfall was 13.27” (190% of average rainfall) • More than 8” attributed to Hurricane Irma Water Management District-Wide Rainfall

October 2017

• October rainfall is 2.84” • 220% of average rainfall • 1 month precipitation outlook predicted as “above average” Rainfall Resulted in Serious Flooding State-wide

Flooded Community along Shingle Creek west of Lake Toho (Kissimmee Area) Upper East Coast Operations • SFWMD releasing as much as possible through S-49 (C-24), S-97 (C-23) and S-99 (C-25) • Gordy Road structured overtopped during Irma • SFWMD utilized Ten Mile Creek Reservoir following the event Current Conditions (as of 0000 hours on October 11, 2017) • Lake Okeechobee at 17.20 feet. • Last time Lake O stage was this high was Oct. 2004 • Lake level increased ~3.5 feet from Irma rainfall, runoff and associated inflows, and October rainfall • Army Corps of Engineers commenced maximum practicable releases to St. Lucie Estuary on September 15th and to Caloosahatchee Estuary on September 19th. • S-80 was releasing ~4600 cfs yesterday; varies with tides. • S-80 flows ranging from 1190-4850 cfs • 770 million – 3.1 billion gallons / day • About 10% of flows from Lake Okeechobee

Current Conditions (continued) • Lake inflows peaked ~38,000 cfs and have reduced to ~14,000 cfs coming mostly from Kissimmee • Maximizing flows through East Coast canals. • There is no capacity in canals south of Lake Okeechobee to take lake releases to the Stormwater Treatment Areas (STAs). • STAs have no capacity to treat lake releases. • WCA-2A and WCA-3A are significantly high, and above their regulation schedules. • These conditions could result in a prolonged period of Lake Okeechobee freshwater releases to the estuaries, including St. Lucie.

Lake Okeechobee Water Quality Lake Okeechobee Water Quality S-80 Structure Looking Downstream Roosevelt Bridge St. Lucie Inlet

Water Quality • Estuary completely fresh water • Temperatures in St. Lucie Estuary ranging from 82-84 degrees Fahrenheit. • No signs (yet) of cyanobacteria blooms

Stuart Causeway

Water Conditions Updates posted on Martin County Website on main screen www.martin.fl.us