Diversions Build Hope for Wetlands
The expense of constructing and operating diversions is a fraction of the estimated cost should the nation fail to protect and restore the Louisiana wetlands. Over the next 20 years, these diversion projects are expected to stabilize or create over a million acres of wetlands.
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Diversion Projects in Louisiana's Coastal Wetlands |
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| Diversion Project | Project # | Description of Project Work | Lead Agency | Location | Project Status | Acres Benefited |
|---|---|---|---|---|---|---|
| Avoca Island Diversion & Land Building | TE-49 | Sediment diversion | COE | Terrebonne Basin | Planning phase | 143 |
| Benney's Bay Sediment Diversion | MR-13 | Construction of conveyance channel, sediment retention devices, dikes, weirs; 50,000 cfs | COE | Mississippi River Delta Basin | Construction scheduled March 2004 | 5,828 |
| Caernarvon Freshwater Diversion* | N/A | Construction of five culverts and inflow and outflow channels | COE; State of Louisiana | Breton Sound Basin | Construction completed 1991 | 77,000 |
| Caernarvon Diversion Outfall Management | BS-03a | Construction of flow-through culverts with water controls at eight sites, three plug closures with armor; restoration of 13,000 feet of spoil bank | NRCS | Breton Sound Basin | Construction completed 2002 | 1,132 |
| Channel Armor Gap Crevasse | MR-06 | Enlargement of existing crevasse to allow additional flow and sediment deposition | COE | Mississippi River Delta Basin | Construction completed 1997 | 936 |
| Davis Pond Freshwater Diversion | N/A | Construction of four gated culverts, inflow and outflow channels, guide levees and rock weir | COE; State of Louisiana | Barataria Basin | Construction completed 2002 | 777,000 |
| Delta-Building Diversion at Myrtle Grove | BA-33 | Installation of five gated box culverts and a conveyance channel; construction of a pump station | COE | Barataria Basin | Engineering and design phase | 8,891 |
| Delta-Building Diversion North of Fort St. Philip | BS-10 | Construction of new conveyance channel with cuts allowing fresh water to divert into adjacent open waters | COE | Breton Sound Basin | Construction scheduled March 2004 | 2,473 |
| Delta-wide Crevasses | MR-09 | Construction of five new crevasses; dredging of existing crevasses; installation of plug in Raphael Pass crevasse to force more water through splays | NMFS | Mississippi River Delta Basin | In construction (1st dredging cycle completed; three more dredging cycles scheduled) | 2,386 |
| Freshwater Introduction South of Highway 82 | ME-16 | Installation of water control structures; plug removal, structure modification; canal enlargement | FWS | Mermentau Basin | Construction scheduled spring 2004 | 296 |
| Grand Bayou/GIWW Freshwater Diversion | TE-10 | Deepening existing channel and installation of weir to reduce saltwater intrusion and retain fresh water | FWS | Terrebonne Basin | Construction scheduled April 2005 | 1,808 |
| Lake Boudreaux Basin Freshwater Intro& Hydrologic Mgmt | TE-32 | Dredging and installation of sluice gates and outfall management structures for fresh water introduction | FWS | Terrebonne Basin | Construction scheduled May 2004 | 619 |
| Mississippi River Water Reintroduction into Bayou Lafourche | BA-25b | Installation of receiving intake structure/siphon system; 1,000 cfs | EPA | Barataria Basin | Engineering and design phase | 104,399 |
| Central and East Terrebonne Basin Freshwater Delivery Enhancement* | TE-42 | Improve distribution of fresh water from the GIWW | FWS | Terrebonne Basin | Proposed complex project | To be determined |
| Myrtle Grove Siphon | BA-24 | Installation of six siphon pipes; construction of leveed outfall channel to facilitate distribution of fresh water and sediments; 2,100 cfs | NMFS | Barataria Basin | Not scheduled | 1,119 |
| Naomi Siphon* | BA-03 | Installation of eight siphons | State of Louisiana/ Plaquemines Parish | Barataria Basin | Construction completed 1993 | Not measured |
| Naomi Outfall Management | BA-03c | Installation of two weirs to maximize sediment retention and nutrient uptake | NRCS | Barataria Basin | Construction completed 2002 | 633 |
| Opportunistic Use of the Bonnet Carre Spillway | PO-26 | Raising spillway pins to allow flow and reduce salinities | COE | Pontchartrain Basin | Not scheduled | 117 |
| River Reintroduction into Maurepas Swamp | PO-29 | Installation of two culverts; construction of receiving pond; 1,500 cfs | EPA | Pontchartrain Basin | Construction scheduled January 2005 | 36,121** |
| Small Freshwater Diversion to the Northwestern Barataria Basin | BA-34 | Installation of siphons; gapping of spoil banks and culverts | EPA | Barataria Basin | Construction scheduled May 2005 | 5,134** |
| Small Sediment Diversions | MR-01b | Construction of conveyance channels | State of Louisiana | Mississippi River Delta Basin | Construction completed 1993 | 6,719 |
| South Lake DeCade Freshwater Introduction | TE-39 | Installation of water control structures on south shore and enlargement of canal | NRCS | Terrebonne Basin | Construction scheduled September 2004 | 201 |
| West Bay Sediment Diversion | MR-03 | Construction of a conveyance channel; 20,000 to 50,000 cfs | COE | Mississippi River Delta Basin | Construction scheduled September 2003 | 9,831 |
| West Point-a-la-Hache Siphon* | BA-04 | Installation of eight 27-inch tubes to siphon water | State of Louisiana | Barataria Basin | Construction completed 1991 | Not measured |
| West Point-a-la-Hache Outfall Management | BA-04c | Installation of three earthen plugs and three weirs; restoration of channel banks to enhance distribution and reduce saltwater intrusion | NRCS | Barataria Basin | Hydrologic modeling phase | 1,087 |
*Non-CWPPRA project
**Acres of swamp