The following information was compiled regarding flood risk, flood insurance designations, levee structure and other matters in an analysis and mapping plan released Friday by the Federal Emergency Management Agency.
Comments were also included on freeboard, which measures the distance from the base flood elevation to the top of the levee.
Issues with freeboard can prevent levees from receiving accreditation. Accreditation impacts the risk category property is placed under for flood insurance matters.
All of the following levees are earthen structures.
* Inter-River
Levee System
Flood source: St. Francis River
Location: Right bank of river, made up of two segments. Starts downstream from Mud Creek and extends to south Butler County border with Arkansas. Small break at Highway 53 where there is natural high ground, before continuing south.
Length: 31 miles
Risk reduction: North segment is not shown as providing flood risk reduction. South segment not shown on effective flood insurance rate map.
Insurance designation: Upper West levee is Zone A
*Impacted people: 2,066
*Impacted structures: 1,387
Freeboard notes: Levee overtops and is freeboard deficient along upstream portion; majority of levee meets minimum 3-foot freeboard.
Operation: Army Corps of Engineers constructed and operated.
* Drainage Dist. 7 Levee
Flood source: Black River
Where: Segmented levee, right bank of river, from Poplar Bluff to south Butler County border.
Length: 28 miles
Risk reduction: Not shown as providing flood risk reduction.
Insurance designation: Zone AH
Insurance study: 2010, lacks freeboard, has failed at various locations, does not adequately withstand 1-percent annual chance flood.
*Impacted people: 602
*Impacted structures: 347
Freeboard notes: Levee overtops and is freeboard deficient along multiple locations.
Operation: Locally constructed, operated and maintained.
* Ring Levee/N. Inter-River Drainage District
Flood source: Black River
Where: Left bank Black River, south of Highway 60 to M Ditch.
Length: 27 miles, includes south portion ring levee.
Risk reduction: Not shown as providing flood risk reduction.
Insurance designation: Zone A
Insurance study: 2010, portion of southern ring levee along County Highway 209 is lower than the 1-percent annual chance flood.
*Impacted people: 677
*Impacted structures: 348
Freeboard notes: Levee overtops upstream, multiple locations lack minimum 3-foot freeboard.
Operation: Locally constructed, operated and maintained.
* Central Clay Co. Drainage Dist.
Flood source: Black River
Where: Left bank Black River, from north Country Road 240, extends beyond south Butler County boundary.
Length: 5 miles, within Butler County
Risk reduction: Not shown as providing flood risk reduction.
Insurance designation: Zone A, within Butler County
*Impacted people: 14 (within Butler County)
*Impacted structures: 10 (within Butler County)
Freeboard notes: Meets minimum 3-foot freeboard.
Operation: Army Corps of Engineers constructed, turned over to public sponsor for operation and maintenance.
* W. Clay
Drainage Dist.
Flood source: Black River
Where: Located along right bank of Black River, near Cane Creek. Begins just north of Butler County boundary and continues south to Arkansas.
Length: 0.7 miles, within Butler County
Risk reduction: Not mapped
Insurance designation: Zone AH
*Impacted people: 0 (within Butler County)
*Impacted structures: 0 (within Butler County)
Freeboard notes: Meets minimum 3-foot freeboard
Operation: Army Corps of Engineers constructed, turned over to public sponsor for operation and maintenance.
* Cane Creek Levee
Flood source: Cane Creek
Where: Along Cane Creek, near Harviell, starts at Union Pacific Railroad and ends at Highway 158.
Length: 0.7 miles
Risk reduction: Not shown as providing flood risk reduction.
Insurance designation: Zone A
*Impacted people: 53
*Impacted structures: 31
Freeboard notes: Overtops significantly.
Operation: Not in Army Corps of Engineers levee safety program.
* Agricultural
Ditch Levees
The majority of the agricultural levees in this levee analysis and mapping procedure plan within Butler County are located between the Black River and St. Francis River along ditches. The only exception are on Black River systems, located along the right bank of the Black River, between the river and the Drainage District No. 7 levee system. These levee systems are not mapped on the 2010 flood insurance rate map. These levees are not in Army Corps of Engineers levee safety program.
Levee on Black River; Flood source: Black River; *Impacted people: 0; *Impacted structures: 0; Freeboard notes: Overtops significantly.
M-Ditch Levee; Flood source: Ditch; *Impacted people: 72; *Impacted structures: 46; Freeboard notes: Overtops at multiple locations.
Ditch A Levee; Flood source: Ditch; *Impacted people: 15; *Impacted structures: 10; Freeboard notes: Overtops significantly.
Lake Slough Ditch Levee; Flood source: Ditch; *Impacted people: 40; *Impacted structures: 15; Freeboard notes: Overtops at multiple locations.
* Drainage Dist. 12
Known as the East Poplar Bluff Ring Levee. It has a levee analysis and mapping plan from 2015. It was not included with this project.
Flood source: Black River
Where: ring levee along left bank of Black River, within and adjacent to city limits of Poplar Bluff
Risk reduction: Provides protection under a provisionally accredited levee designation.
*Figures approximate, based on 2000 census block.