FAQs – Proposed Water Management Solution for the Yazoo Backwater Area
- How does the draft preferred approach from the agencies protect homes in the 5-year floodplain?
- A preliminary analysis was conducted to identify and categorize structures that could potentially be inundated during a 5-year frequency event. Although further assessment will be necessary, the current evaluation indicates 24 homes are within close proximity to the extent of the 5-year inundation model. Of these 24 homes, 17 have some form of existing floodproofing mitigation measures (i.e. elevated above ground, ring levee, or berms). Solutions including elevating homes, ring levees, and buy-outs will be offered for any primary residence found to be inundated within the 5-year floodplain. For those additional homes that may not be inundated but are still affected by flooding, such as those with limited road access and septic system inundation, we are working with local and federal partners to determine options for potentially raising road elevations and developing septic system improvements or alternatives. USACE is collecting additional structure information and welcomes any help or input from the public. If you are concerned that your home was not accounted for, please use the following link to add the location for future analyses. URL to structure input survey: https://survey123.arcgis.com/share/2950754bc55c48b99fcfd099bc08614
- How will farmland stay in production in the 5-year floodplain with the recommended approach?
- The new approach would allow backwater flooding up to the 5-year floodplain in the non-crop season and up to the 2-year floodplain in the proposed crop season. Existing farming operations above the 2-year floodplain will be protected from backwater flooding during a defined crop season. This will allow farmers access to conduct field preparation, seed the land, and conduct post-harvest activities.
- How will the recommended approach affect downstream communities?
- USACE will thoroughly evaluate the extent to which floodwater discharged from the pumps may affect water levels in communities downstream of the pumping station. If there is any potential for the project to increase flooding levels for these communities, flood risk reduction solutions for affected residences will also be included as part of the overall project. Potential solutions could include the solutions being considered to address residual inundation inside the Yazoo Backwater Area including elevating homes, ring levees, and buy-outs.
- How is this approach designed to be more environmentally friendly than previously considered plans?
- Periodic flooding is important to wetlands across the 5-year floodplain of the Yazoo Backwater Area and to the fish and wildlife these wetlands support. The recommended approach would be designed to allow more wetlands across the 5-year floodplain to receive periodic flooding than the previously proposed plans. This means the recommended approach would have fewer adverse impacts on wetlands, fish, and wildlife than the previously proposed plans.
- What specific changes are being considered to make this approach less environmentally damaging than previously considered plans?
- The recommended approach includes several changes designed to make it less environmentally damaging than previous proposals. First, previous proposals were designed to limit backwater flooding above 87 feet above sea level year-round. The new approach would allow backwater flooding up to the 5-year floodplain in the non-crop season and up to the 2-year floodplain in the crop season. Second, previous proposals included a 14,000 cfs pumping station. The new approach would include a 25,000 cfs pumping station. The larger series of pumps would allow more resource-sustaining periodic flooding before the pumps have to be turned on to manage water. With a smaller pump capacity such as 14,000 cfs, the pumps would need to be turned on earlier in the year and at lower flood elevations to ensure that water could be managed to the same target elevations. Turning the pumps on at lower elevations means more impacts to wetlands, fish, and wildlife. Third, as part of the new approach, the water control structure at Steele Bayou would remain open until water levels reach 78 feet above sea level in the Yazoo Backwater Area—8 feet higher than current operation of the structure allows. Keeping the structure open longer would increase aquatic connectivity between the Yazoo River and the Yazoo Backwater Area benefiting fishery resources and water quality. The ability to make this change is aided by the higher capacity pumping station. These three changes would allow more wetlands across the 5-year floodplain to receive periodic flooding of ecologically important areas than the previously proposed plans.
- Will the project still have adverse impacts on wetlands, fish, wildlife, and other ecological resources?
While the new project is designed to reduce impacts to wetlands, fish, wildlife, and other ecological resources as compared to previously proposed plans, the new project is likely to have adverse impacts to ecological resources. These impacts will be thoroughly evaluated, and we expect to have preliminary estimates of project impacts in the coming months. The agencies will also be exploring and identifying options for compensatory mitigation once the impacts have been estimated. The agencies expect that the project will have sufficient compensatory mitigation consistent with Clean Water Act requirements.
- What kind of approaches are being considered to mitigate adverse impacts on ecological resources?
- The potential mitigation strategy may include components within and outside the Yazoo River Basin. A key component of the mitigation strategy being contemplated within the Yazoo River Basin is construction of a series of wells northeast of the Yazoo Backwater Area that would be used to augment stream-flow in certain Yazoo Backwater Area streams during low flow times of the year. Another key component of the mitigation strategy would be implementation of ecosystem restoration and enhancement projects, both within and outside the Yazoo River Basin. These projects would be implemented in areas that would benefit fish and wildlife communities similar to those being impacted.
- What are the next steps for implementing the recommended approach?
- The agencies are taking the feedback from the May 4-5 engagement sessions, as well as comments received via this website, and USACE will deliver a preferred approach to CEQ in June. After that, an important next step would be to review the proposal for consistency with the Clean Water Act, National Environmental Policy Act, and other applicable laws and regulations. The recommended approach will need funding from Congress to be implemented.
- Other pump capacities, including a 25,000 cfs pumping station, were evaluated and rejected in the 2007 Supplemental Environmental Impact Statement and USACE determined in the 2007 SEIS that a 14,000 cfs pumping station was the Least Environmentally Damaging Practicable Alternative. What has changed to now support a 25,000 cfs pumping station?
- Capacity is only one aspect of a flood risk reduction solution that includes a pump. Other important aspects are the elevations the pumps would be turned on and the elevations floodwaters would be allowed to reach. The purpose of a larger pump would be to allow more resource-sustaining periodic flooding before the pumps have to be turned on to manage water elevations. With a smaller pump capacity, such as 14,000 cfs, the pumps would need to be turned on earlier in the year at lower flood elevations to ensure that water could be managed to the same non-crop and crop season target elevations. Turning the pumps on at lower elevations means more impacts to wetlands, fish, and wildlife.
- If operating plans can change over time, how are the agencies able to ensure that these reductions in adverse impacts are not simply fleeting?
- We acknowledge that operating plans associated with USACE civil works projects can change over time and such changes may be necessary to address changed circumstances. Regarding this project, the agencies are proposing to put specific processes in place to ensure maximum transparency and input should any changes be considered in the operating plan, specifically: 1) USACE will seek public comment on any future changes to the operating plan; and 2) USACE, USEPA, and USFWS will enter into a Memorandum of Agreement that will ensure that all three agencies will be part of the approval process for any future changes to the operating plan for the new project.