Brandywine Creek Dam No. 9 Reservoir Report

Last Updated: December 5, 2025

Brandywine Creek Dam No.


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Summary

9, also known as Rockland Dam, is a historic rockfill dam located in Rockland, Delaware. Built in 1800, this dam serves primarily for recreational purposes, providing a serene backdrop for outdoor enthusiasts to enjoy the surrounding area. With a height of 9.19 feet and a length of 140 feet, the dam offers a storage capacity of 807 acre-feet and covers a surface area of 21.81 acres.

Situated on the Brandywine Creek, this dam has a low hazard potential and is currently not rated in terms of condition assessment. Despite its age, the dam has undergone no major modifications over the years and does not have a spillway. The risk assessment for this structure is considered high, with a risk character summary indicating a level 2 risk. Although the dam is not regulated by the state and does not require frequent inspections, it remains a key feature in the local landscape and provides a peaceful retreat for visitors to enjoy the natural beauty of the area.

Overall, Brandywine Creek Dam No. 9 stands as a testament to early engineering feats in water resource management. While not actively used for flood control or water supply, its historical significance and recreational value make it a noteworthy landmark in the New Castle County area. As climate and water resource enthusiasts explore the region, this dam serves as a reminder of the importance of preserving and appreciating our natural resources for future generations to enjoy.

Year Completed

1800

Dam Length

140

Dam Height

9.19

River Or Stream

BRANDYWINE CREEK

Primary Dam Type

Rockfill

Surface Area

21.81

Drainage Area

304.37

Nid Storage

807

Outlet Gates

None

Hazard Potential

Low

Foundations

Unlisted/Unknown

Nid Height

9
       
Seasonal Comparison

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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.