A Comparison of the Benefits of Northern and Southern Everglades Storage
Rajendra Paudel, Ph.D. Thomas Van Lent, Ph.D. The Everglades Foundation The Comprehensive Everglades Restoration Plan (CERP)
• U.S. Army Corps and South Florida Water Management District developed CERP
• Authorized in 2000 by Florida Legislature and by Congress (WRDA 2000)
• 68 individual projects each requires authorization and appropriations
• Key components: water storage, remove barriers to flow, maintain flood protection and water supply, increase water delivery Prioritization
The Legacy Florida Act States:
“The Department of Environmental Protection and the South Florida Water Management District shall give preference to those Everglades restoration projects that reduce harmful discharges of water from Lake Okeechobee to the St. Lucie or Caloosahatchee estuaries in a timely manner.”
Goal: to get some objective information that should help determine the proper prioritization of projects based on the new Legacy Florida mandate. Northern Everglades and EAA Storage
• North Storage Reservoir - 200,000 acre-ft storage - CERP Component A
• Everglades Agricultural Area North Storage Storage Reservoir Reservoir - 360,000 acre-ft EAA - CERP Component G Reservoir
• Storage capacity is based on the official CERP project description Hydrologic Modeling
• The South Florida Water Management Model (SFWMM) is a physically-based, integrated surface water-groundwater model • 2 mile x 2 mile grid size (known as “2x2 Model”) • Climatic data from 1965 to 2000 • Simulates major components of hydrologic cycles in South Florida as well as operational criteria • 2x2 Model was used to develop CERP Scenarios Description
1. Existing Condition Base (ECB): current C&SF infrastructure and operating rules
2. Northern Reservoir (NSR): exactly the same as the Existing Condition Base, but with the addition of the North of Lake Okeechobee Storage Reservoir
3. EAA Reservoir Shallow (SSR_Shallow): exactly the same as the Existing Condition Base, but with the addition of the EAA Reservoir (CERP Component G)
4. EAA Reservoir Deep (SSR_Deep): same as the “SSR_Shallow” but with deep EAA Reservoir (30,000-acre footprint and 12 ft maximum depth) Lake Okeechobee Operational Triggers
Above this line, water is diverted to NSR
Below this line, water is released from NSR Results: Lake Okeechobee Performance
Stage Duration Curves for Lake Okeechobee
17 ECB 16 NSR SSR_Shallow 15
) SSR_Deep
D
V 14
G
N
,
t 13
e
e
f
( 12
e
g
a t 11
S
10
9
8 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 Percent Time Equaled or Exceeded Results: Lake Okeechobee Outflows
Mean Annual Flood Control Releases from Lake Okeechobee for the 36 ys (1965 - 2000) Simulation 1100 Releases to North Storage 1000 EAA Storage Water Conservation Areas 900 Reg. Releases to Caloosahatchee Estuary Reg. Releases to St. Lucie Estuary 49
) 48 r 800 L8 to Tide a 77
e 79
y
/
t
f 700
-
e 69 r 67 213 c 600 217
a
0 140
0 150
0 500
1
( 207 e 400 199
m
u
l
o 300
V 366 390 200 310 325 100 54 53 51 0 ECB NSR SSR_Shallow SSR_Deep Regional Simulation Model for Basins (RSM-BN)
• Link-node application of Regional Simulation Model
• Model covers northern basins, Caloosahatchee and St. Lucie river watersheds, EAA and STAs
• Climatic data from 1965 - 2005
• Used in the Central Everglades Project
RSM-BN schematic of EAA http://www.saj.usace.army.mil/Missions/Environmental/ Ecosystem-Restoration/Central-Everglades-Planning- Project/ Comparisons with RSM-BN Simulations
Stage Duration Curves for Lake Okeechobee
17 ECB 16 NSR Model output
15 SSR for RSM =
)
D 1965-2005
V 14
G
N
,
t 13
e
e
f
( 12
e
g
a t 11
S
10
9
8 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 Percent Time Equaled or Exceeded Comparisons with RSM-BN Simulations
Mean Annual Regulatory Releases from Lake Okeechobee for the 41 ys (1965 - 2005) Simulation 1000 Regulatory Releases to St. Lucie Estuary 900 Regulatory Releases to Caloosahatchee Estuary Regulatory Releases to South 800 87
)
r
a 700
e
y
/
t
f - 600 234
e
r
c 164 156
a
0 500
0
0
1
(
400
e
m
u l 300 o 414 401 V 481 200
100
59 64 0 ECB NSR SSR Why EAA Reservoir Outperforms Northern Reservoir? Southward Flow across Tamiami Trail
Average Annual Overland Flow across Transects 17 & 18 (1965 - 2000) 1400 Dry Season (Nov-May) Wet Season (Jun-Oct) 1200
)
t
f
- 669
c 1000
a
0
0
0
1 800
( 489
w 476
o
l
F 600 442 442
d
n
a
l
r
e 400 v 704
O 467 480 200 357 357
0 NSM462 ECB NSR SSR_Shallow SSR_Deep Southwestward flow in Central Shark River Slough
Average Annual Overland Flow across Transects 27 (1965 - 2000) 1600 Dry Season (Nov-May) 1400 Wet Season (Jun-Oct)
)
t f 1200
-
c 739
a
0
0 1000
0
1
(
w 800
o
l
F
d 600 449 461
n
a
l
r 414 414
e v 400 777
O
200 381 391 290 291
0 NSM462 ECB NSR SSR_Shallow SSR_Deep Depth Duration Curves Depth Duration Curves (Contd …) Summary
• EAA reservoir reduced the harmful discharges from lake Okeechobee to the estuaries nearly by 50% while the Northern Reservoir reduced the volume of harmful discharges by 6%.
• Northern Reservoir provided more water supply benefits to the lake.
• EAA reservoir increased dry season flows in Central Shark River Slough by 35% compared to no changes in flows with Northern Reservoir.
• Deep reservoir in EAA provided additional dry season flows (13,000 ac-ft/year) across Tamiami Trail compared to the shallow reservoir with the same storage capacity. Thank You!
Contact: Rajendra Paudel Hydrologist, Everglades Foundation Email: [email protected]