Wellington Nap D-21b Reservoir Report

Last Updated: December 9, 2025

Wellington Nap D-21b, located in Lafayette, Missouri, is a crucial water resource structure designed by the USDA NRCS in 1973.


°F

°F

mph

Wind

%

Humidity

Summary

This earth dam serves primarily for flood risk reduction along the TR-Missouri River, with a height of 43 feet and a length of 400 feet. The dam has a storage capacity of 105 acre-feet, providing essential debris control and flood protection for the surrounding area.

Despite its significant role in managing water resources, Wellington Nap D-21b has been classified as having a low hazard potential but an unsatisfactory condition assessment as of March 2021. The dam's last inspection in December 2016 revealed the need for improvement, highlighting the importance of regular maintenance and monitoring to ensure its effectiveness in mitigating flood risks. With a moderate risk assessment rating, it is crucial for authorities to address any deficiencies promptly to enhance the dam's resilience against potential climate-related challenges.

As part of the Dam and Reservoir Safety Program, Wellington Nap D-21b is regulated, permitted, inspected, and enforced by the state of Missouri. With its critical role in flood protection and water management, ongoing risk assessment and maintenance measures are essential to safeguard the surrounding community and ensure the dam's continued effectiveness in the face of changing climatic conditions.

Year Completed

1973

Dam Length

400

Dam Height

43

River Or Stream

TR-MISSOURI RIVER

Primary Dam Type

Earth

Surface Area

7

Drainage Area

659

Nid Storage

105

Structural Height

43

Outlet Gates

None

Hazard Potential

Low

Foundations

Soil

Nid Height

43
       
Seasonal Comparison

Weather Forecast

Dam Data Reference

Condition Assessment

Satisfactory
No existing or potential dam safety deficiencies are recognized. Acceptable performance is expected under all loading conditions (static, hydrologic, seismic) in accordance with the minimum applicable state or federal regulatory criteria or tolerable risk guidelines.
Fair
No existing dam safety deficiencies are recognized for normal operating conditions. Rare or extreme hydrologic and/or seismic events may result in a dam safety deficiency. Risk may be in the range to take further action. Note: Rare or extreme event is defined by the regulatory agency based on their minimum
Poor A dam safety deficiency is recognized for normal operating conditions which may realistically occur. Remedial action is necessary. POOR may also be used when uncertainties exist as to critical analysis parameters which identify a potential dam safety deficiency. Investigations and studies are necessary.
Unsatisfactory
A dam safety deficiency is recognized that requires immediate or emergency remedial action for problem resolution.
Not Rated
The dam has not been inspected, is not under state or federal jurisdiction, or has been inspected but, for whatever reason, has not been rated.
Not Available
Dams for which the condition assessment is restricted to approved government users.

Hazard Potential Classification

High
Dams assigned the high hazard potential classification are those where failure or mis-operation will probably cause loss of human life.
Significant
Dams assigned the significant hazard potential classification are those dams where failure or mis-operation results in no probable loss of human life but can cause economic loss, environment damage, disruption of lifeline facilities, or impact other concerns. Significant hazard potential classification dams are often located in predominantly rural or agricultural areas but could be in areas with population and significant infrastructure.
Low
Dams assigned the low hazard potential classification are those where failure or mis-operation results in no probable loss of human life and low economic and/or environmental losses. Losses are principally limited to the owner's property.
Undetermined
Dams for which a downstream hazard potential has not been designated or is not provided.
Not Available
Dams for which the downstream hazard potential is restricted to approved government users.