The DEC project investigates many different types of technology.  The paragraphs below show examples site and describe the techniques in more detail.

• Grade Control Structures
• Bank Stabilization
• Channel Modification
• Flood Water Retarding Structures
• Debris Basins
• Levees
• Land Treatment

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Grade Control Structures: Return to Top

Four types of grade control structures will be used for DEC projects to provide control of headcutting erosion. Both high drop and low drop grade control structures will be used to control headcutting and channel bed degradation in streams. The magnitude and severity of the headcutting will dictate the type of structure to be used. For minor grade control of small tributaries and newly formed gullies, riser pipes or pipe drops will be installed. Riser pipes also serve as a sediment trap and often times provide temporary or permanent ponds. Box culvert grade control structures are used for minor grade controls at road crossings, particularly when bridge and/or culvert replacements are necessary.

Bank Stabilization: Return to Top

Bank stabilization structures include stone paving and transverse and longitudinal toe dikes. These structures are used to retard or prevent bank caving or failure. Several types of materials can be used in bank stabilization projects, with stone rip-rap being the most commonly used type.

Channel Modifications: Return to Top

Channel modifications include deepening, widening, straightening, and construction of new channels. Such modifications are used only when necessary to reestablish the stream channel, provide proper sediment transport, and/or to provide sufficient flood control.

Floodwater Retarding Structures: Return to Top

The floodwater retarding structure is a relatively small impoundment usually constructed in or near the headwaters of a tributary. The impoundment controls the amount and velocity of floodwater and serves as a sediment trap. The control of floodwater peaks indirectly helps in the control of headcutting on the larger streams.

Debris Basins: Return to Top

Debris basins are similar to the floodwater retarding structures, except debris basins have a much smaller drainage area (less than 300 acres) and generally do not have control structures that allow manual release of floodwater. Debris basins are designed to trap sediment and woody debris, thereby assisting in the maintenance of downstream channel capacities. Two sizes of debris basins are usually constructed based upon the amount of the drainage area that they will control; drainage areas less than 100 acres will require a debris basin of one to three acres. If the drainage area is 100 to 300 acres, a debris basin, called an intermediate dam, will be constructed, and will encompass three to five acres.

Levees: Return to Top

Levee construction is used as an integral part of the overall system plan for sediment, erosion, and flood control. The size and type of levee to be constructed will depend upon the other structures planned for a given watershed and the amount of protection/control desired. Pumping plants will be incorporated to some of the levee systems to provide for release of interior floodwater.

Land Treatment: Return to Top

Land treatment involves a variety of measures including strip cropping, conservation tillage, greenbelts, terracing and grassed waterways. These measures are used to preclude or reduce erosion on farmlands, particularly raw croplands, and to reduce sediment loadings to the stream channels.