Client: U.S. Army Corps of Engineers - Little Rock District
Completion Date: 12/25/2002
The planning process balances economic development and environmental considerations when considering if there is a Federal interest in providing flood damage prevention, providing eco-system restoration, enhancing recreation opportunities, and addressing other water resources problems in areas like the Jordan Creek Watershed. This planning process consists of a reconnaissance phase and, if benefits exceed costs, a feasibility phase. The products of these two phases are the 905 (b) Reconnaissance Report and the Feasibility Report. These reports enable reviewers to reach independent conclusions regarding the reasonableness of the recommendations, document compliance with applicable statutes and policies, and provide a sound basis for decision makers to make recommendations to Congress. This Section 905 (b) Reconnaissance Report was completed to determine if project benefits exceed costs and if there is a Federal interest in proceeding to the feasibility phase. The purpose of this report is to document the basis for this finding and to establish the scope of the feasibility phase.
Six planning steps are set forth for focusing the planning effort and eventually selecting and recommending a plan for authorization. The six planning steps are: (1) specify problems and opportunities; (2) inventory and forecast conditions; (3) formulate alternative plans; (4) evaluate effects of alternative plans; (5) compare alternative plans; and (6) select a recommended plan. The phases of the planning process typically differ in the emphasis that is placed on each of the steps. In the iterations conducted during the reconnaissance phase, the specification of problems and opportunities is emphasized. However, because the initial screening of preliminary plans that results from the other steps is critical to the scoping of the feasibility phase studies, the other steps are not ignored.
Springfield is located in southwestern Missouri. The study area encompasses approximately six miles along Jordan Creek, generally centered on the Chestnut Expressway between U.S. Highway 65 to the east and State Highway 13 to the west in the northern half of the city of Springfield, Missouri. The study area is urban, with commercial, industrial, and residential development and some open spaces. Springfield is developing a civic park, Jordan Valley Park, in the central portion of the area. The principal flood problem is insufficient channel size, whether vertical wall culvert (covered or uncovered), open channel, or narrow bridge. The increase in flood heights resulting from development and the absence of a storm system is also significant. Flood runoff from the newly developed areas in the headwaters of the north and south branches of Jordan Creek affect flood heights along all of Jordan Creek, as well as its outfall, Wilson Creek. During large floods, a small percentage of runoff enters sinkholes. Although some sinkholes have been filled in, most are open. Some of the unfilled sinkholes provide significant flood storage capacity.
In summary, the range of costs for flood damage reduction and/or eco-system restoration in a particular area is approximately $9,000 to $30,000 per acre. Estimated land with a potential for wetland or detention basin development is approximately 250 acres. The excavated volume (10-foot depth) for channel construction is approximately 18 million cubic feet of soil. A structural cost can reflect a particular percent reduction of flooding in a targeted area, with the remainder of the floodplain remedied by non-structural measures (relocation).
