March 1971 ft'm L Environmental Statement West Tennessee Tributaries Feature Mississippi River and Tributaries Project (Obion and Forked Deer Rivers) Prepared By U. S. Army Engineer District, Memphis, Tennessee WEST TENNESSEE TRIBUTARIES (Obion and Forked Deer Rivera) Environmental Statement 1. Project Description. The West Tennessee Tributaries project is designed to provide flood control and drainage benefits to the agricul­ tural lands and the small urban centers adjacent to the Obion and Forked Deer Rivers and their major tributaries in We3t Tennessee. The project was authorized by the Flood Control Act of 1948, based on studies con­ tained in House Document 627, 80th Congress, 2d Session, and was last reviewed in House Document 308, 88th Congress, 2d Session. As of the last review, the authorized project consisted of enlargement and realign­ ment of 110 miles of main stem and major tributary channels in the Obion River system and similar work on 106 miles of the Forked Deer system. Approximately 59 miles .of construction have been completed on the main stem and North, South and Rutherford Forks of the Obion River and approxi­ mately 10 miles along the main stem and South Fork of the Forked Deer River. The authorized work in the combined watersheds is about 32 per­ cent complete. A field report now under review proposes to modify the project to provide fish and wildlife mitigation measures which will achieve a better balance in man's use of his environment in the Obion and Forked Deer Rivers basin than'provided for by the original project. The modifications recom­ mended for inclusion in the project consist of acquisition of about 14,400 acres of floodplain lands; development of these lands for.management for fish and wildlife purposes; development of the Tennessee Game and Fish Com­ mission's Tigrett Wildlife Management Area and the undeveloped portion of Gooch Wildlife Management Area; and ninor modification of the project, such as provision of smaller channels in certain reaches, and beautification measures at highway crossings consisting of dressing, fertilizing and seeding of the spoil banks and berms. The location of the areas to be acquired and the extent of the development for fish and wildlife purposes would be based on mutually agreeable plans developed jointly by the Corps of Engineers, the Department of Interior, and the Tennessee Game and Fish Commission prior to the time the work is accomplished. Modification of the authorized project to include channel changes, beautification measures, and development of approximately 7,800 acres of publicly-owned lands for fish and wildlife use can be accomplished under existing authorities without awaiting further Congressional action. Development might typically include low weirs in channels adjacent to these areas to form permanent pools for water supply, and pumping sta- tions, low levee3, and culverts with controlled outlets to manipulate water levels for management purposes. Based on information provided by the Department of Interior, the bottomlands of the Obion and Forked Deer Rivers are considered an important link in the Mississippi waterfowl flyway, since they comprise a significant habitat necessary to sustain the waterfpwl population. Preservation of a portion of this habitat, developed to sustain the present wildfowl population, is in the national interest; therefore, acquisition and development at Federal expense to mitigate project- induced losses appears appropriate. In accordance with Section 3 of the Fish and Wildlife Coordination Act of 1958, acquisition of the 14,400 acres of floodplain lands at Federal expense will require specific author! zation by the Congress. Plans for development of these areas would be similar to those for existing publicly-owned lands. The location of the project, the extent cf presently authorized work and its status of completion, and the proposed modifications are shown on the attached nap. In formulation of the project, only tangible benefits have been evaluated for comparisons with tangible costs. The resulting benefit-cost ratio of the project, modified to include proposed mitigation measures, is 1.3. The Corp3 recognizes that the project will result in intangible benefits and damages which are impossible to quantify in monetary terms. However, consideration has geen given to these values in the formulation of recommendations. 2. Environmental Setting Without the Project. The Obion and Forked Deer Rivers basin (also referred to as the West Tennessee Tributaries) is a tributary to the Mississippi River, encompassing all or part of fourteen counties in northwestern Tennessee and a small part of two counties in western Kentucky. The drainage area of about 4,500 square miles is almost equally divided between the Obion ar.d the Forked Deer watersheds, as shown on the attached rap. The two river3 and their major tributaries flow through narrow, relatively flat valleys which gradually broaden toward the west. The linear flatness of the valleys gives a bayou effect to the streams. The adjacent uplands are gently rolling. Both streams emerge from the hills into the alluvial valley of the Mississippi through 2 which the Obion River flows for about 31 miles (improved mileage) and the Forked Deer River about 13 miles (improved mileage).* The Forked Deer enters the Obion 3 miles above its mouth. Water in the streams is turbid, flows are sluggish, and overbank flooding is frequent. The associated woodland, occupying the lower zone of the floodplain, is composed of such bottomland types as cypress, tupelo gum, overcup oak, bitter pecan, hackberry, elm, ash, sweetgum,' water oak, and others. This wetland ecosystem is especially favorable for waterfowl and the basin draws hunters from generally throughout the state, particularly from the large urban centers of Memphis and Nashville. The Department of Interior considers the area to be of significant value in maintaining Mississippi flyway waterfowl populations by providing rest­ ing and wintering habitat. It is also a wood duck production area. No known rare or endangered species of botanical and zoological origin are kno\ra to exist in the project area. A natural heron rookery is known to exist on the north side of the South Fork of Obion River just west of the Weakley County line. The state’s largest cypress tree is located on the right bank of Middle Fork of Obion River immediately upstream from its confluence with South Fork. The channel improvement is being designed to preserve the tree. Mineral resources in the basin consist of sand, clay and gravel. There are no known historical or archeological sites in the area that would be endangered by the proposed project. Prior to the start of construction of the project, the maximum flood- plain consisted of 180,600 acres of bottomland forest and 155,400 acres of agricultural land. The channels of all the major tributaries and many of the minor tributaries have been replaced by straightened artificial ditches constructed by the local people for drainage purposes in the 1920*s and 1930*s. With the decline of agricultural land values and crop prices during the "Great Depression" of the 1930's, the local people were unable to properly maintain these ditches and as a result they have largely reverted to a clogged condition. The open lands occupy the higher edge of the_alluvial plains and typically are used as family farming operations. Flooding has iri_the past deterred use of low lands for crop pro- ___ duction. However, since”the advent of soybeans in the early 1960’s as a high return cash crop which cen mature during the short growing season remaining after the high water in the river bottoms subsides, the influ­ ence of flooding on land clearing is not as controlling as it once was. The landowners, as a result, are clearing bottomland timber in large blocks for soybean production, evon above the limits of any authorized work. 3 Income of basin inhabitants is derived primarily from agriculture. There are also nurse reus small manufacturing and processing plants. .Market­ ing of forest products is dono primarily for supplementing the agricultural income of individual landownera. Other minor income is attributable to the bottomlands in the fora of selling or leasing hunting rights on private lands. Disruption of normal living conditions by flooding of homes, busi­ nesses, roads, and farmlands affects about 17-,000 farm families and. a segment of the urban population of Dyarsburg, Tennessee,•and other rural communities at the edga of the floodplain. 3 * Identify The Environmental Impacts of the Proposed Action. The construc­ tion of the project will contribute to the improvement of the day to day economic and social well-being of the people of this economically deprived region. A comparison of the median incomes of families in the Tennessee counties which are wholly or partially in.the basin with the median family income for the nation shows that tho overage income of basin families is 45 percent of that of the typical American family. Therefore, providing the basic essentials of life, including a desirable standard of living for their families ar.d an adequate educational opportunity for their children, is a primary desire of basin inhabitants. The project will enhance the ■ human environment through increased crop yields, increased agricultural production, enhancement of land values and, as currently recommended for modification, assure the preservation of quality fishing and hunting oppor­ tunities. Greater yields and production will result In additional net income for tho individual farmer and for the businessmen in the rural communities who are dependent on expenditures by farm families and the pro­ cessing of farm products for their livelihood. Enhancement of land values will provide county governments with a higher tax base from which to draw the income needed to provide an improved level of service to the people of tho basin. Mitigation measures proposed for inclusion in the project emphasize the preservation and development of wetland habitat, since this type of environment is the most adversely affected by the flood control and drainage improvements.