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CHAPTER IV: WILDLIFE HABITATS FOR MISSISSIPPI’S SGCN,

THREATS AND CONSSERVATION ACTIONS^201

12.3 - 12.7 UPPER COASTAL PLAIN

The Upper Coastal Plain region covers most of the northern half of Mississippi. Portions of the
Tombigbee, Pearl, Big Black, Yazoo and Lower Mississippi North drainages lie in this region. Stream
characteristics such as size, gradient, and the and substrate type vary in this region. Streams in this
region are separated into four categories: small, loess hills, medium and large.

12.3. Tombigbee Drainage

„ Value to SGCN - 184

„ Rank - 1st of 18 Lotic and Lentic Systems

DESCRIPTION AND LOCATION

UEGCP

Streams in this category are tributaries of the Tombigbee River, which

has been highly modified by construction of the Tennessee-

Tombigbee Waterway. Fauna found nowhere else in the state inhabit

streams in this region. The streams of this drainage fall into three size

categories: small, medium and large.

CONDITION AND CONSERVATION STATUS
The Tombigbee drainage has been highly modified by the
construction of the Tennessee-Tombigbee Waterway. The waterway
is a series of impoundments and canals with locks ands dams for navigation. This has effectively
isolated many tributaries by creating a lentic barrier between lotic systems. Many of the lotic tributaries
have been altered by channelization. Headcutting, erosion, and sedimentation are often a problem, even
in unchannelized reaches.

Because of the large number of species of concern in this drainage, and the
disturbed state of the drainage, it is considered imperiled in the state.

12.3a. Small streams. (see 12.2a for definition).

12.3b. Medium streams. (see 12.2b for definition).

12.3c. Large Streams. Large streams have drainage basins greater

than 1,000 square miles, typically have little canopy cover and contain a

wide array of microhabitat types ranging from deep runs and pools to

Small Stream, Tombigbee River Drainage

Tombigbee Drainage