Freshwater Discharges to Lake Worth Lagoon Julie O. Bishop - PowerPoint PPT Presentation

Freshwater Discharges to Lake Worth Lagoon Julie O. Bishop Environmental Resources Management December 13, 2013

LAKE WORTH LAGOON • Orig. FW • 20 mi long • ½ mi wide • North Palm Beach to Ocean Ridge • 13 Municipalities • 480 sq. mile watershed • Urbanized

Seagrass Mapping  Aerial Mapping ~5 yrs C-17 C-51  2001 & 2007 seagrass coverage 22% or >1600 acres  2012 & 2013 unable to capture aerial photo due to discharges and reduced water clarity  Grant funded by State Legislative Appropriation C-16

Seagrass Mapping  2012 aerial failed due to poor water clarity  2013 methodology sampling 1,000 points 2013 Adjacent to Rybovich Marina

SEAGRASS MAPPING 2013 C-17 C-51 C-16 Central Lagoon South Lagoon North Lagoon  70% with seagrass  7% with seagrass  50% with seagrass

Overall frequency of seagrass occurrence in the Lake Worth Lagoon, 2000-2013 1200 1000 Total # of Cells with Seagrass 800 600 400 200 0

Oyster Station March 2012 August 2013

C-51 Sediment Management Project Area • WPB Golf Course S-155 Control Structure

Take Away Points:  SFWMD is doing what it can to reduce discharges.  ‘System’ lacks water storage.  CERP, CEPP, A-1, Rock Pits, Mecca, C-51 Reservoir.  Too much freshwater kills seagrasses and oysters.  Seagrasses and oysters can recover.  Muck sediments are left behind.  Muck smothers most living organisms.  C-51 Sediment Trap helps.  Reducing discharges will also reduce sediments.

C-51 Canal John’s Island Oysters  Freshwater Discharges contain C-51 Ibis Isle Restoration suspended sediments & high nutrients  Results  Muck Deposits  Increased Turbidity  Blankets Sand Substrate Grassy Flats  Reduces Biodiversity (Proposed ) Snook Island Natural Area

Capping w ith Sand Shooter

Grassy Flats Restoration Project • Caps 12 acres of muck Proposed seagrass (10.52 ac) Enhanced seagrass (9.31 acres) Proposed cordgrass (1.14 ac) Proposed mangrove (0.33 ac) Proposed open area (0.27 ac) Proposed oyster/artificial reef (0.57 ac) Existing boat access to remain (30' wide) Existing mangrove planter (0.8 ac) Existing mangrove planter (0 8 ac) # "Danger: Submerged Rock" sign • Partners sharing cost of $2.7M: • USFWS ($777,000) • FDEP/NOAA ($110,000) ( ) • USACE ($842,000?) • Legislative appropriation ($110,000?) • PBC ($920,000, including in-kind) PBC ($920,000, including in kind) • FWC (in-kind) • WPBFC (in-kind) • MIA (in-kind) C Construction to begin Spring 2013 t ti t b i S i •

Julie O. Bishop Environmental Resources Management w w w.LWLI.org