R. Clark No.2 Reservoir Report
Nearby: R. Clark No.1 R. Clark No.3
Last Updated: December 13, 2025
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Summary
Clark No.2 is a privately owned dam located in Dewey, South Dakota, along the TR-GRAND river. Built in 1947, this Earth-type dam stands at a height of 12 feet and has a length of 370 feet, with a maximum storage capacity of 80 acre-feet. Despite its low hazard potential, the dam is regulated by the South Dakota Department of Environment and Natural Resources (DENR), with regular inspections, permitting, and enforcement in place to ensure its safety and compliance with state regulations.
Managed by private owners, R. Clark No.2 serves as a vital water resource in the region, providing irrigation and flood control benefits to the surrounding area. With a normal storage capacity of 30 acre-feet and a maximum discharge rate of 2100 cubic feet per second, the dam plays a crucial role in managing water flow along the TR-GRAND river. Despite being classified as "Not Rated" in terms of condition assessment, the dam remains a key infrastructure for water management in South Dakota.
As a part of the St. Paul District of the US Army Corps of Engineers, R. Clark No.2 is subject to state jurisdiction and regulatory oversight. While it has not been modified or rated for risk assessment, the dam's emergency action plan status and adherence to guidelines remain unclear. With its strategic location and importance for water resource management, R. Clark No.2 stands as a testament to the ongoing efforts to balance water resource utilization with environmental conservation and safety considerations in the region.
Year Completed |
1947 |
Dam Length |
370 |
Dam Height |
12 |
River Or Stream |
TR-GRAND |
Primary Dam Type |
Earth |
Hydraulic Height |
12 |
Nid Storage |
80 |
Hazard Potential |
Low |
Nid Height |
12 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Moreau R Near Whitehorse Sd
|
35cfs |
Grand R At Little Eagle Sd
|
47cfs |
Moreau R Near Faith Sd
|
14cfs |
Cedar Creek Nr Raleigh
|
20cfs |
Oak Cr Near Wakpala Sd
|
10cfs |
Cannonball River Nr Raleigh
|
40cfs |
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.
R. Clark No.2