Freshwater Diversions and Louisiana The Davis Pond Project

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Freshwater Diversions and LouisianaThe Davis
Pond Project

• Dr. John W. Day
• April 27, 2005

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STAKEHOLDER PARTICIPATION IN RIVER DIVERSIONS

• The Caernarvon Project
• The Davis Pond Project

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Caernarvon Diversion Structure - Flood 1992
(aerial view)
Ideally, wetland spatial maintenance occurs by
pulsed sediment delivery from rivers, which would
offset effects of RSLR, land subsidence, and
storm-induced erosion.
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Caernarvon Freshwater Diversion

• Construction completed 1991
• Maximum Capacity 220 m3s-1
• 1100 km2 of fresh to brackish wetlands

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Caernarvon Freshwater Diversion
Discharge Canal
Mississippi River
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Caernarvon Management Goals

• Enhancement of emergent marsh vegetation growth
• Reduction of marsh loss
• Increase significant commercial and recreational
  fisheries productivity
• Increase significant commercial and recreational
  wildlife productivity

Caernarvon Interagency Advisory Committee 1993
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Hierarchical Information Flow
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PULSES The importance of pulsed physical
events for watershed sustainability in coastal
Louisiana
Coastal Ecology Institute Louisiana State
University And Center for Ecology and
Environmental Technology University of Louisiana
at Lafayette
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Targeted Approach to Environmental Problems
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Caernarvon 1927
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River Flooding viaCaernarvon Diversion

• Discharge capacity is 227 m3/sec
• (8000 cfs).
• Normal operation is up to 113 m3/sec.
• Our experimental pulses are
• 14 and 184 m3/sec
• (500 and 6500 cfs).

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MODIS image of Diversion Flow
March 5, 2001
March 21, 2001
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Low Flow (lt40 m3s-1)
High Flow (211 m3s-1)
S O N D J F M A M J J A S O N D J F M A M J J A
-- 2000 -- ---------------2001-------------
--------2002--------
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Pulses Experimental Daily Discharge
Discharge (m3/s)
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Marsh Processes
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MODIS image of Diversion Flow
March 5, 2001
March 21, 2001
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Sheet Flow Through Mass Balance
6700 cfs (100)
1800 cfs (27)
3240 cfs (48)
1630 cfs (24)
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Accretion at Reference Area -Algal
Accretion at Site 432 -Mineral
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NitrateNitrite
0
Diversion
Distance from Diversion (km)
(?mol L-1)
Marine
50
200
Discharge (m3s-1)
0
F
W
S
S
F
W
S
S
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AcknowledgementsCaernarvon Interagency Advisory
Committee

• Bruce Baird (USACE)
• George Barisich (Shrimp)
• Gerry Bodin (USFWS)
• Clay Cosse (St. Bernard)
• David Dawson (Land owner)
• Heather Finley (LDWF)
• Kenny Fox (Oysters)
• Bill Good (LDNR)

• Paul Gremillion (LDNR)
• Jim Hasik (Recreational Fishing)
• Bren Haase (NMFS)
• Ken Hemphill (LDHH)
• David Oge (LDEQ)
• Jeanene Peckham (EPA)
• John Scurish (Plaquemines)
• Chuck Villarrubia (LDNR)

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DAVIS POND
MISSISSIPPI RIVER
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Davis Pond Project Purposes

• Reduce saltwater intrusion
• Re-establish favorable salinities
• Reduce the rate of land loss, and
• Improve fish and wildlife habitat

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• Project Impacts
• Provide an extra 15 million annually in
  fishing benefits and 300,000 for recreation
• Save 33,000 acres of wetlands
• Freshen 777,000 acres of marshes and bays

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Davis Pond Freshwater Diversion Project

• Features
• Diversion Structure 10,650 cfs (4,800,000
  gpm) capacity
• Diversion Channel 2.2 miles from river to
  ponding area
• Pump Station 570 cfs (256,000
  gpm) capacity
• Ponding Area 9,311 acres (14.5
  square miles)
• Containment Levees 19 miles (channel
  ponding area)
• Oyster leases Relocate if adversely
  impacted
• Rock Weir 1.8 miles on Lake
  Cataouatches north shore (Ponding Areas
  outlet to Lake Cataouatche)

• Cost and Schedule Cost (Federal
  State) 120,000,000 Annual Benefits
  15,295,000 Diversions to begin Summer
  2002

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New Orleans, LA
Davis Pond Freshwater Diversion
RIVER
LA HWY 18
Union Pacific RR
MISSISSIPPI
BN-SF RR
Luling, LA
U.S. HWY 90
Ponding Area
Willowdale
(9,300 acres)
Subdivision
LAKE CATAOUATCHE
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Davis Pond ProjectConcerns and Issues

• Over Freshening
• Flooding
• Water Quality
• Impacts on Fisheries
• Others?

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Davis Pond Diversion under construction
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