Hearns Pond Dam
The comment submission period has ended. Thank you!
Welcome to the Delaware Department of Transportation's virtual workshop. The goals of the virtual workshop format are to make it easier for more people to view the project information, and to reduce the costs involved in traditional public workshops. This is a workshop regarding the improvements to Hearn's Pond Dam.
[Location Map] Hearns Pond Dam is located on Clear Brook, North of Seaford in Sussex County Delaware. The dam is owned by the State of Delaware, Department of Natural Resources and Environmental Control (DNREC). The dam is operated and maintained by the Division of Fish and Wildlife. The pond formed by the dam is used for fishing and other recreational activities. An historic mill structure is situated at the south end of the dam. Water from the pond was used to supply power to the mill. There is a boat ramp on the north end of the dam allowing access to the lake.
[Flood and Existing Conditions Photos] Hearns Pond Dam was overtopped during storms of August 11, 2001 and June 25, 2006. The dam was damaged by both storms. Because of these failures, DNREC funded a study to evaluate the condition and potential hazards of the dam and develop alternatives to bring the dam into conformance with Delaware Dam Safety Regulations. The study indicated that the existing spillway and bridge at Hearns Pond Dam do not have capacity to convey discharge from the required Design Storm event. Therefore, rehabilitation of the dam is necessary to bring it into conformance with Dam Safety Regulations. In addition to hydraulic deficiencies the existing spillway structure, consisting of twin concrete box culverts, is in poor overall condition. The concrete has numerous spalls, cracks, and areas of exposed reinforcing steel. The water level in the pond is controlled by two pairs of double sliding gates about 4-feet high and 5-feet wide. One of the gates is inoperable.
[Proposed Plan and Elevation] [Construction Plan] The proposed rehabilitation consists of replacing the spillway and the twin box culverts at the dam with a larger spillway and a larger bridge/culvert to pass the flow during the 100 year storm event, and provide embankment overtopping protection that will allow safe passage of the design storm event. A new low level outlet gate with manual operator will be provided to allow manipulation and drawdown of the lake level.
The new larger spillway will be constructed of concrete and semi-circular in plan, slightly greater than 100 feet long measured along the curve. The new twin box culverts will each be 20 feet wide and nearly 10 feet high. The earth embankments will be armored using precast articulated concrete blocks. The concrete blocks will be covered with topsoil and seeded along the downstream slope. The boat ramp will be re-oriented to facilitate access. The top of the earth dam will be raised on both ends by about 1.25 feet. This work will also require raising the height of the bulkhead on the south end of the dam, and removal of the garage and small barn at that location.
A steel sheet pile cofferdam will be driven in the lake to isolate the work area from the lake, so that the lake level will be maintained during construction. The lake will not be lowered for construction. The cofferdam will allow construction to continue during fish spawning season. Once the new spillway and culverts are completed, the cofferdam will be removed.
No repair work is planned for the Mill Building under this contract other than monitoring to ensure it is not damaged during construction.
Construction is anticipated to begin from the spring of 2015 to the spring of 2016.
The boat ramp and parking area on the north end of the dam will be closed during construction.
If you would like to make comments, you may submit them online by clicking on the link above, "Send us your comments", or you may call toll free to 800-652-5600, or call locally in the Dover area 760-2120. Comments may also be mailed to DelDOT Community Relations P.O. Box 778, Dover, Delaware, 19903. Comments are due within 30 days of the posting of this virtual workshop on the internet.
Thank you for participating in the Delaware Department of Transportation's Virtual Workshop.