Summary
The dam is situated on the Little Wapsipinicon River, near the city of Elma, and serves primarily for recreational purposes, offering a surface area of 52.5 acres for outdoor activities. With a height of 11 feet and a length of 932 feet, the dam has a storage capacity of 358 acre-feet and a drainage area of 21 square miles.
Although the dam has a low hazard potential and is currently rated as "Not Rated" in terms of condition assessment, it is regulated by the Iowa Department of Natural Resources, which oversees permitting, inspections, and enforcement. The structure features an uncontrolled spillway and a soil foundation, making it an earth dam type. Despite not having outlet gates or locks, the dam has a moderate risk assessment of level 3, indicating a need for ongoing risk management measures to ensure its safety and integrity for the surrounding community.
Given its location within the Rock Island District and under the jurisdiction of the Iowa DNR, the Lylah Marsh Dam represents a valuable resource for both water recreation enthusiasts and climate advocates. As efforts continue to maintain and monitor the dam's condition, its role in providing recreational opportunities and water storage for the region remains essential, highlighting the intersection of human infrastructure with natural resources in the context of water resource management and climate resilience.
Year Completed |
1960 |
Dam Length |
932 |
Dam Height |
11 |
River Or Stream |
LITTLE WAPSIPINICON RIVER |
Primary Dam Type |
Earth |
Surface Area |
52.5 |
Drainage Area |
21 |
Nid Storage |
358 |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
11 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Little Cedar River Near Ionia
|
70cfs |
Cedar River At Charles City
|
450cfs |
Turkey River At Spillville
|
28cfs |
Upper Iowa River At Bluffton
|
421cfs |
Wapsipinicon River Near Tripoli
|
106cfs |
Upper Iowa River At Decorah
|
257cfs |
Dam Data Reference
Condition Assessment
SatisfactoryNo 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
HighDams 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.
Area Campgrounds
| Location | Reservations | Toilets |
|---|---|---|
Lake Hendricks Park Campground
|
||
Pioneer County Park
|
||
Haus County Park
|
Lylah Marsh Dam