EXPLANATION OF SUBSEGMENT REVISIONS IN LOWER MISSISSIPPI RIVER ALLUVIAL PLAINS, SOUTHERN PLAINS TERRACE AND FLATWOODS, AND COASTAL DELTAIC MARSHES ECOREGIONS

Explanation of Subsegment Revisions November 17, 2014

Revised Current Subsegment Subsegment Name Revised Description Subsegment Revision(s) Number Number

Bayou Manchac—From headwaters to Split along Baton Rouge Fault to exclude SPTF drainage. DO 040201 LA040201_00 Bayou Manchac Amite River criteria revised. Ward Creek—From headwaters to 040202 LA040201_00 Ward Creek confluence with Dawson Creek Split along Baton Rouge Fault to exclude LMRAP drainage. Amite River—From La. Highway 37 to 040302 LA040302_00 Amite River LMRAP Ecoregion boundary Split near Clay Cut Bayou to exclude LMRAP drainage.

040303 LA040303_00 Amite River No change DO criteria revised. Colyell Bay; includes Colyell Creek and Middle Colyell Creek—From Hood Road to Split near Hood Road to exclude SPTF drainage. DO criteria 040305 LA040305_00 Colyell Bay Colyell Bay revised. Amite River—From LMRAP Ecoregion Split near Clay Cut Bayou to exclude SPTF drainage. DO 040306 LA040302_00 Amite River boundary to Amite River Diversion Canal criteria revised. West Colyell Creek—From headwaters to Split off from 040305 near Hood Road to exclude SPTF 040307 LA040305_00 West Colyell Creek Hood Road drainage. Middle Coyell Middle Colyell Creek—From headwaters to Split off from 040305 near Hood Road to exclude SPTF 040308 LA040305_00 Creek Hood Road drainage. Colyell Creek—From headwaters to confluence with, and including, Little Colyell Split off from 040305 near Hood Road to exclude SPTF 040309 LA040305_00 Colyell Creek Creek drainage.

040401 LA040401_00 Blind River No change DO criteria revised. Amite River 040402 LA040402_00 Diversion Canal No change DO criteria revised.

040403 LA040403_00 Blind River No change DO criteria revised.

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Explanation of Subsegment Revisions November 17, 2014

Revised Current Subsegment Subsegment Name Revised Description Subsegment Revision(s) Number Number

040404 LA040404_00 New River No change DO criteria revised. Blood River—From headwaters to George Isolated Blood River drainage from Tickfaw River 040502 LA040502_00 Blood River White Road subsegment, placed in SPTF. Natalbany River—From headwaters to La. 040503 LA040503_00 Natalbany River Highway 22 Split at La. Highway 22 to exclude drainage in LMRAP. Ponchatoula Creek—From headwaters to 040505 LA040505_00 Ponchatoula Creek La. Highway 22 Split at La. Highway 22 to exclude drainage in LMRAP. Tickfaw River—From La. Highway 42 to Lake Removed Blood River drainage from subsegment. DO 040506 LA040502_00 Tickfaw River Maurepas criteria revised. Natalbany River—From La. Highway 22 to Split at La. Highway 22 to exclude drainage in SPTF. DO 040507 LA040503_00 Natalbany River Tickfaw River criteria revised. Ponchatoula Creek— From La. Highway 22 Split at La. Highway 22 to exclude drainage in SPTF. DO 040508 LA040505_00 Ponchatoula Creek to Natalbany River criteria revised. Pass Manchac—From Lake Maurepas to Lake Pontchartrain; includes interlacustrine waters from North Pass to Mississippi River Littoral edge edited to reflect 2010 NAIP Lake 040601 LA040601_00 Pass Manchac levee Pontchartrain shoreline. DO criteria revised. Split to isolate Mississippi Bayou and associated canals 040602 LA040602_00 Lake Maurepas Lake Maurepas from Lake Maurepas. Selsers Creek—From headwaters to Sisters 040603 LA040603_00 Selsers Creek Road Split to exclude drainage in LMRAP. South Slough; includes Anderson Canal to 040604 LA040604_00 South Slough Interstate Highway 55 borrow pit canal DO criteria revised. South Slough Littoral edge edited to reflect 2010 NAIP Lake 040604-001 LA040604_001 Wetland No change Pontchartrain shoreline.

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Explanation of Subsegment Revisions November 17, 2014

Revised Current Subsegment Subsegment Name Revised Description Subsegment Revision(s) Number Number

Mississippi Bayou and associated canals; includes Dutch Bayou, Reserve Relief Canal 040605 LA040602_00 Mississippi Bayou and Hope Canal Split to isolate Lake Maurepas. DO criteria revised. Selsers Creek—From Sisters Road to South 040606 LA040603_00 Selsers Creek Slough Split to exclude drainage in SPTF. DO criteria revised. Boundary with 040702 adjusted to Interstate Highway 12 040701 LA040701_00 Tangipahoa River No change alignment. Boundary with 040701 adjusted to Interstate Highway 12 alignment; littoral edge edited to reflect 2010 NAIP Lake Pontchartrain shoreline, split to exclude Bedico Creek 040702 LA040702_00 Tangipahoa River No change drainage. DO criteria revised. Bedico Creek—From headwaters to Split to exclude Tangipahoa River drainage. DO criteria 040705 LA040702_00 Bedico Creek Tangipahoa River revised. Tchefuncte River—From headwaters to US 040801 LA040801_00 Tchefuncte River Highway 190; includes tributaries (Scenic) Split to exclude LMRAP drainage. Ponchitolawa Ponchitolawa Creek—From headwaters to 040802 LA040802_00 Creek US Highway 190 (Scenic) Split to exclude LMRAP drainage. Northern boundary adjusted to exclude the high relief near 040803 LA040803_00 Tchefuncte River No change La. Highway 22. Edited to include drainage previously attributed to 040801, 040804 LA040804_00 Bogue Falaya River No change Tchefuncte River. Chinchuba Swamp Littoral edge edited to reflect 2010 NAIP Lake 040805 LA040805_00 Wetland No change Pontchartrain shoreline. East Tchefuncte Littoral edge edited to reflect 2010 NAIP Lake 040806 LA040806_00 Marsh Wetland No change Pontchartrain shoreline.

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Explanation of Subsegment Revisions November 17, 2014

Revised Current Subsegment Subsegment Name Revised Description Subsegment Revision(s) Number Number

Tchefuncte River—From US Highway 190 to Split to exclude SPTF drainage; adjusted eastern boundary Bogue Falaya River; includes tributaries to exclude Bogue Falaya River drainage. DO criteria revised. 040807 LA040801_00 Tchefuncte River (Scenic) Tchefuncte River–From Bogue Falaya River Split to exclude Black River drainage, Ponchitolawa Creek 040808 LA040802_00 Tchefuncte River to La. Highway 22 (Scenic) SPTF. DO criteria revised. Black River does not drain into Tchefuncte River in this Black River—From headwaters to La. subsegment; isolated to its own drainage. DO criteria 040809 LA040802_00 Black River Highway 22 revised. Bayou LaCombe—From headwaters to 040901 LA040901_00 Bayou LaCombe Interstate Highway 12 (Scenic) Split to exclude LMRAP drainage.

Bayou LaCombe—From CDM Ecoregion boundary to Lake Pontchartrain (Scenic) 040902 LA040902_00 Bayou LaCombe (Estuarine) Split to exclude LMRAP drainage. Bayou Cane— From headwaters to US 040903 LA040903_00 Bayou Cane Highway 190 (Scenic) DO criteria revised. Bayou Cane—From CDM Ecoregion boundary to Lake Pontchartrain (Scenic) 040904 LA040904_00 Bayou Cane (Estuarine) Split to exclude LMRAP drainage. Bayou Liberty—From headwaters to LMRAP 040905 LA040905_00 Bayou Liberty Ecoregion boundary Split to exclude LMRAP drainage. Bayou Liberty—From La. Highway 433 to Bayou Bonfouca; includes Bayou de Chien 040906 LA040906_00 Bayou Liberty (Estuarine) Split to exclude LMRAP drainage.

040907 LA040907_00 Bayou Bonfouca No change DO criteria revised. Bayou Bonfouca—From CDM Ecoregion 040908 LA040908_00 Bayou Bonfouca boundary to Lake Pontchartrain (Estuarine) Split to exclude LMRAP drainage.

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Explanation of Subsegment Revisions November 17, 2014

Revised Current Subsegment Subsegment Name Revised Description Subsegment Revision(s) Number Number

Bayou LaCombe—From Interstate Highway 040912 LA040901_00 Bayou LaCombe 12 to US Highway 190 (Scenic) Split to exclude SPTF drainage. DO criteria revised. Bayou LaCombe—From US Highway 190 to CDM Ecoregion boundary (Scenic) 040913 LA040902_00 Bayou LaCombe (Estuarine) Split to exclude CDM drainage. DO criteria revised.

Bayou Cane—From US Highway 190 to CDM 040914 LA040904_00 Bayou Cane Ecoregion boundary (Scenic) (Estuarine) Split to exclude CDM drainage. DO criteria revised. Bayou Liberty—From LMRAP Ecoregion 040915 LA040905_00 Bayou Liberty boundary to La. Highway 433 Split to exclude SPTF drainage. DO criteria revised. Split to isolate Bayou Paquet LMRAP drainage from Bayou Bayou Paquet—From headwaters to Bayou Liberty LMRAP drainage (confluence in CDM). DO criteria 040916 LA040906_00 Bayou Paquet Liberty (Estuarine) revised. Bayou Bonfouca—From La. Highway 433 to 040917 LA040908_00 Bayou Bonfouca CDM Ecoregion boundary (Estuarine) Split to exclude CDM drainage. DO criteria revised. Littoral edge edited to reflect 2010 NAIP Lake Pontchartrain shoreline, Edited to correct topological error 041001 LA041001_00 Lake Pontchartrain No change - loop with adjacent 041302. Bonnet Carre Littoral edge edited to reflect 2010 NAIP Lake 041101 LA041101_00 Spillway No change Pontchartrain shoreline. DO criteria revised. Bayou Labranche—From headwaters to 041201 LA041201_00 Bayou Labranche Lake Pontchartrain (Scenic) (Estuarine) Split to exclude CDM drainage. DO criteria revised.

041202 LA041202_00 Bayou Trepagnier No change DO criteria revised. Edited to correct topological error - loop at NW 041203 LA041203_00 Duncan Canal No change corner/Lake Pontchartrain. Bayou Traverse—From headwaters to 041204 LA041201_00 Bayou Traverse LMRAP Ecoregion boundary (Estuarine) Split to exclude LMRAP drainage.

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Explanation of Subsegment Revisions November 17, 2014

Revised Current Subsegment Subsegment Name Revised Description Subsegment Revision(s) Number Number

Lake Pontchartrain Drainage Canals in Jefferson and Orleans Parishes Edited to correct topological error - loop with adjacent 041302 LA041302_00 (Estuarine) No change 041001.

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