The federal standard for levee system integrity assessment and rehabilitation eligibility under Public Law 84-99.

The USACE Levee Safety Program uses a rigid four-value rating scale that applies uniformly to every inspection item across all six checklist sections. Unlike numerical scoring systems that produce a continuous range, the A/M/U system is categorical: each item either meets the standard, falls short but remains functional, fails to meet the standard, or does not apply to the segment under inspection. This simplicity is deliberate. The rating is not an engineering judgment call with room for interpolation — it is a compliance determination. An item rated Acceptable (A) means the inspector has confirmed that the component is in satisfactory condition with no deficiencies and will function as intended during the next flood event. A Minimally Acceptable (M) rating signals one or more minor deficiencies that require corrective maintenance but will not seriously impair performance during the next flood event. An Unacceptable (U) rating indicates serious deficiencies that would compromise the system during a flood. The fourth option, Not Applicable (N/A), is used when a feature does not exist in the segment — for example, a segment with no pump station marks all pump station items as N/A. The critical behavioral rule is that certain general preparedness items — specifically Emergency Supplies and Equipment and Flood Preparedness and Training — do not permit the Unacceptable option at all. For these items, the only valid ratings are Acceptable, Minimally Acceptable, or Not Applicable, reflecting that these are programmatic readiness checks rather than physical deficiency assessments.

The USACE inspection checklist is organized into six sections, each addressing a different component category of a levee system. Not all sections apply to every segment: Sections 3 through 6 are toggled on or off depending on which physical assets exist within the segment boundary. This modular structure means a simple earthen levee with no structures might only require Sections 1 and 2, while a complex urban flood protection system could require all six. Section 1 (General Items) is mandatory for every inspection and evaluates the levee sponsor's organizational readiness: whether current Operations and Maintenance manuals exist, whether emergency supplies and equipment are staged, and whether personnel have completed flood preparedness training. Section 2 (Levee Embankments) is the primary structural section, covering 15 inspection items from vegetation and sod cover through slope stability, erosion, settlement, cracking, animal burrow damage, seepage, and revetment condition. Section 3 (Floodwalls) applies where concrete floodwall structures are present and covers surface condition, structural settlement, monolith joints, and seepage. Section 4 (Interior Drainage System) addresses the culverts, gate wells, and discharge areas that manage water on the protected side of the levee. Section 5 (Pump Stations) is the most extensive, with 21 checklist items spanning mechanical equipment, electrical systems, fuel systems, and structural condition. Section 6 (Flood Damage Reduction Channels) covers paved or unpaved channels that form part of the flood control system.

The inspection program is administered by the U.S. Army Corps of Engineers Levee Safety Program.

The USACE Levee Safety Program uses a segment-based aggregation model. A levee system may consist of multiple segments, each potentially operated by a different local sponsor. The system rating is determined by the lowest-rated segment — a single failing segment brings down the entire system. Within each segment, the aggregation follows three rules. First, if every item is rated Acceptable (or N/A), the segment rating is Acceptable. Second, if one or more items are rated Minimally Acceptable and no Unacceptable items exist (or if Unacceptable items are present but an engineering determination concludes they will not prevent performance), the segment rating is Minimally Acceptable. Third, if one or more items are rated Unacceptable and would prevent the system from performing as intended, or if any Minimally Acceptable item has persisted uncorrected for more than two years, the segment rating is Unacceptable.

This two-year escalation rule is one of the most consequential features of the USACE inspection framework. It means that a Minimally Acceptable finding is not simply a lower-priority version of Acceptable — it is a ticking clock. If the levee sponsor does not correct the deficiency within two inspection cycles (typically two years for annual routine inspections), the finding automatically escalates to Unacceptable regardless of whether the physical condition has worsened. The practical effect is that an M rating on a single item — even something as seemingly minor as vegetation management — can eventually cause the entire system to lose federal rehabilitation eligibility under Public Law 84-99. This mechanism incentivizes proactive maintenance and ensures that minor deficiencies are not indefinitely deferred.

The inspection framework defines two types of assessments that feed into this system. A Routine Inspection (RI) is a visual inspection conducted annually to verify proper operation and maintenance. A Periodic Inspection (PI) is a more comprehensive evaluation conducted every five years by a multidisciplinary team that includes a professional engineer to assess operational adequacy and structural stability. Both inspection types use the same A/M/U checklist, but the Periodic Inspection involves deeper analysis and often produces more detailed findings. In the digital form, every item rated M or U requires an accompanying observation remark documenting the specific deficiency — this conditional validation ensures that no sub-standard rating exists without a justification record.

For infrastructure standards that use numerical condition scoring instead of categorical ratings, see the NEN 2767 condition assessment standard. Browse all inspection standards in the standards library.

Section 2 of the USACE inspection checklist addresses the earthen embankment — the physical structure that constitutes the primary flood barrier. With 15 rated items, it is the second largest section after pump stations and the most universally applicable, since every levee segment includes an embankment. The items are ordered to follow a logical walk-through from surface conditions to structural integrity to subsurface behavior. Vegetation and Sod Cover evaluates whether the embankment surface has adequate grass coverage to resist erosion during overtopping or wave action; bare soil patches, deep-rooted woody growth, or excessive weed cover all warrant an M or U rating. Encroachments addresses unauthorized structures, vehicles, equipment, or materials placed on or against the levee that could interfere with flood fighting, inspection, or structural performance. Slope Stability covers evidence of slide failures, bulging, or movement on the levee slopes. Erosion and Bank Caving evaluates evidence of surface wash, rill formation, or bank undercutting on the riverside. Settlement, Depressions, and Rutting each target distinct forms of embankment deformation — vertical subsidence, localized surface lows, and traffic-induced ruts that could concentrate flow during overtopping.

Animal Control is a uniquely important item in levee inspection: burrowing animals such as muskrats, nutria, groundhogs, and beavers can create through-going seepage pathways in the embankment that dramatically increase the risk of internal erosion and piping during high water. An active animal burrow on a levee is not a nuisance pest problem — it is a structural integrity threat. The Culverts and Discharge Pipes item evaluates pipes that penetrate the embankment, checking for joint separation, corrosion, and backfill settlement around the pipe exterior. Riprap Revetments and other bank protection systems are assessed for displacement, loss of toe material, and vegetation growth that may indicate insufficient stone coverage. The final two items — Underseepage Relief Wells and Seepage — address subsurface water behavior. Relief wells are active dewatering systems that reduce hydraulic pressure beneath the levee foundation; they must be regularly tested and maintained. Seepage observations document any evidence of water movement through or under the embankment, from damp spots and sand boils to active flow. Seepage is the single most dangerous condition for an earthen levee because it can initiate piping failure within hours during a flood event.