MRC Statement Low Water Hearing August 2019

Major General R. Mark Toy, President

 Mississippi River Commission 

General Toy, Members of the Commission, and Distinguished Guests: 

My name is W. Dustin Boatwright. I am the Chief Engineer of The Little River Drainage District (LRDD) headquartered in Cape Girardeau, Missouri and serve as Missouri’s Regional Engineer for the Mississippi Valley Flood Control Association. LRDD is a major contributor to the St. Francis Basin watershed, draining nearly 2 million acres. The U.S. Army Corps of Engineers (USACE) is authorized to perform major maintenance and improvements within the watershed of the St. Francis Basin, which is an integral part of the Mississippi River and Tributaries Project (MR&T). 

The Little River Drainage District has identified several maintenance, operation, inspection, and communication issues we would like to bring to the attention of the Mississippi River Commission (MRC). We are fortunate many of the issues below are actively being addressed by our Memphis District USACE Partners. 

1.      Scouring and erosion of the West Basin Levee caused by the historic winter flooding of 2015/2016 and further exacerbated by the Spring Floods of 2017 & 2019. The solution is to repair and armor scours with riprap armor. Execution time on this particular project is paramount due to the scour damage increasing with each passing storm event. LRDD is excited to report Memphis District USACE has completed Phase 1 & Phase 2. Phase 3 and 4 designs are complete and awaiting funding for construction. Phase 5 is awaiting funding for design.

2.      Excavation maintenance/repair on the following channels damaged by the historic winter flooding of 2015/2016 along with the spring flooding of 2017 & 2019: Ditch No. 1 Upper (North of Highway EE), Ditch No. 251 Upper and Lower, Ditch No. 66, and Ditch No. 39. All four channels are main outlets for LRDD channels draining nearly 1.2 million acres in the LRDD watershed (See the attached Exhibit “A”). Approximately 1500 miles of upstream channels (blue and purple channels) must be conveyed through the channels under the USACE Memphis District’s major maintenance responsibility (red channels).

3.      A large levee slope failure on the Headwater Diversion Channel Levee, which first occurred following the January 2016 flood and April/May 2017 flood, and was further exacerbated by the spring flooding of 2019. This active slide is 3,500 ft. in length on the landside of the levee. Slope flattening at this location with the readily available material found on site is the best long term solution to correct the issue.

4.      Critical active erosion on Ditch No. 1, along the left descending bank, approximately one-half (1/2) mile and another location approximately two and one-half (2.5) miles upstream from Highway “62” in New Madrid County, Missouri. The Ditch No. 1 channel continues to undercut the levee on the east bank at these two locations. This levee has provided protection from flooding for nearly a century. There are a dozen homes and farming operations that would be devastated if the levee were to breach. LRDD respectfully requests USACE’s immediate attention to armor the two locations with riprap armor. 

5.   Ditch No. 1 channel is meandering badly from the Junction of LRDD Ditch No. 39 with LRDD Ditch No. 1 downstream to the intersection of Highway 60 in Stoddard County, Missouri (approximately 1 mile), threatening the levee on both sides of the channel. The solution is to straighten and place riprap armor along both sides of the channel along this entire 1 mile stretch.

6.   Repair numerous active scours along the north bank of Headwater Diversion Channel near Allenville, Missouri. The major concern is during high-water events the channel is trying to create a cut across an old meandering of the Whitewater River. If a cutoff is created the outfall would be nearly perpendicular to the Headwater Diversion Channel Levee (Mainline Mississippi River Levee). The potential for this uncontrolled perpendicular flow undoubtedly threatens the integrity of the Headwater Diversion Channel Levee.

7.   Scouring and erosion on the Headwater Diversion Channel Levee east of Interstate-55. This location is in need of riprap armoring to protect this portion of levee.

8.  Relief well remediation along the Headwater Diversion Channel Levee in several locations. Recent pump tests along the Headwater Diversion Channel indicated many of the relief wells, installed in the 1980’s, require remediation maintenance. Also, during the future remediation work, the access road along the relief wells is in need of gravel surfacing to allow for unimpeded access during flood events.

9. Sals Creek Levee active scour at the junction of the Ramsey Creek Diversion. This section of levee has active scouring along the levee TOE. This location is in need of riprap armoring to protect the integrity of the Headwater Diversion Channel Levee System.

10. LRDD proposes to improve the Big Lake Gate Structures System Operation Plan to utilize the latest technology to improve the conveyance of runoff through the LRDD and St. Francis Basin system. The current system is utilizing gages mounted directly on the gate structures which trigger automatic operation once the channels reach a set elevation at the structure. This is an old system and has worked well during its time. However, with today’s technology this system can be improved to benefit both the upstream and downstream landowners along with wildlife management in the Big Lake and the Missouri Department of Conservation Hornersville Swamp.The current trend of high intensity, short duration rainfall events are causing rapid rises & falls accompanied by heavy sediment loads entering Big Lake Wildlife Refuge. This is not a good situation for the upstream and downstream landowners, or the fish and wildlife in Big Lake. LRDD is proposing to work with USACE Memphis District, Big Lake National Wildlife Refuge (U.S. Fish and Wildlife Service) and the landowners involved to improve the operation plan to help convey runoff through the system more efficiently with the utilization of upstream gages in conjunction with forward weather forecasting to adjust the gate operation days before runoff reaches the structures. Making early adjustments to this system will drastically improve conveyance of runoff through the St. Francis Basin system. The proposed operation improvements will provide additional runoff storage, less extreme rise and falls in channel/lake elevation, and decreased downstream flood elevations by allowing conveyance of runoff to occur over a longer period of time. The result is undoubtedly a win-win for all involved.  

11. LRDD hereby requests the Operation of the Lake Wappapello Gate Structures be returned to the USACE Memphis District Hydraulics Branch. Currently, Lake Wappapello is being controlled by the USACE St. Louis District, which lies outside of the MR&T footprint. Lake Wappapello is a flood control lake authorized in the Flood Control Act of 1936 (Overton Act) as an integral part of the St. Francis Basin portion of the Mississippi River and Tributaries (MR&T) Project. Currently, USACE Memphis District controls the operation and maintenance of the entire St. Francis Basin portion of the MR&T except for the operation of Lake Wappapello. LRDD respectfully requests the operation of Lake Wappapello be returned to the MR&T footprint with USACE Memphis District controlling the operation for its primary function of Flood Control. 

This concludes the request of The Little River Drainage District. Please give these items careful consideration. Thank you for your time, attention, and continued partnership.  

W. Dustin Boatwright, P.E., M ASCE 

                                                                                    Chief Engineer/Executive Vice President