Knowles Deep Irrigation Pond Dam Reservoir Report
Last Updated: December 5, 2025
Knowles Deep Irrigation Pond Dam, also known as Matthews Lake Dam, is a private dam located in Cobbville, Telfair County, Georgia.
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Summary
Built in 1965 by the Natural Resources Conservation Service, this earth dam stands at 28 feet in height with a storage capacity of 85 acre-feet. The primary purpose of the dam is irrigation, serving a drainage area of 125 acres.
With a low hazard potential and a moderate risk assessment, the dam is deemed to be in good condition, although it has not been rated recently. The dam features an uncontrolled spillway and outlet gates, with an inspection frequency of every five years. Despite not being state-regulated, the dam undergoes regular inspections to ensure its safety and functionality for irrigation purposes. Its unique design and historical significance make it a notable structure for water resource and climate enthusiasts.
Year Completed |
1965 |
Dam Length |
360 |
Dam Height |
28 |
River Or Stream |
UNKNOWN |
Primary Dam Type |
Earth |
Surface Area |
6 |
Hydraulic Height |
23 |
Drainage Area |
125 |
Nid Storage |
85 |
Outlet Gates |
Uncontrolled |
Hazard Potential |
Low |
Foundations |
Unlisted/Unknown |
Nid Height |
28 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Turnpike Creek Near Mcrae
|
0cfs |
Ocmulgee River At Lumber City
|
2080cfs |
Oconee River Near Mount Vernon
|
2230cfs |
Ocmulgee River At Hawkinsville
|
2570cfs |
Tucsawhatchee Creek Near Hawkinsville
|
39cfs |
Altamaha River Near Baxley
|
3480cfs |
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.
Knowles Deep Irrigation Pond Dam