Bank Stabilization Information and Standard Permit Conditions

The following conditions are designed to protect the values for which the Missouri National Recreational River (MNRR) was included in the National Wild and Scenic River system. These conditions apply to activities authorized under Section 404 of the Clean Water Act and Section 10 of the Rivers and Harbors Act. All other federal and state regulations and requirements shall apply to the proposed activity.

The National Park Service (NPS) reviews all US Army Corp of Engineers permit applications within the 59- and 39- mile segments of the Missouri National Recreational River. The NPS is required to review water resource projects, such as bank stabilization, for their impact to the Outstandingly Remarkable Values (ORVs) for which Congress designated segments of the Missouri and Niobrara as Wild and Scenic Rivers. Each project is analyzed for its impacts to the following ORVs:

• Free-flow
• Scenic
• Recreational
• Fish and Wildlife
• Cultural and Ethnographic Resources
• Historic Resources
• Scientific

The NPS reviews each proposed project individually because local site conditions within the designated river reaches vary greatly. Adjacent stabilization, channel conditions, and the potential of the project to cause downstream erosion are all considered.

The NPS promotes the use of ‘bioengineering’ techniques utilizing native materials for stream bank protection. The NPS encourages those considering a bank stabilization project to request a site visit from our staff prior to submitting a permit application to the US Army Corps of Engineers to discuss alternatives and expedite the process. The US Army Corps of Engineers website has more information on the permit application process at: http://www.usace.army.mil/CECW/Pages/reg_permit.aspx

STABILIZATION
BIOENGINEERING TECHNIQUES: Permit Required

Refers to the use of biodegradable material on the active streambank to prevent lateral erosion

1. Toe protection may include tree revetments, live cribwalls, root wads, live siltation, trench pack, brush mattress, dead fascine, vegetated geogrid, coconut logs, jute-mat logs, or native fieldstone.
2. Plant materials should be native to this area. Native plants are adapted to the soils and weather of this area and should germinate and thrive.
3. All construction materials (e.g., erosion control material, stakes and anchoring systems) shall be biodegradable.
4. A Soil Bioengineering Guide (this document provides information on bioengineering techniques including materials and practices): http://www.fs.fed.us/eng/php/library_card.php?p_num=FS-683P

RIPRAP REVETMENT: Permit Required

Refers to the placement of riprap material on the active streambank to prevent lateral erosion.

1. Riprap shall consist of or be covered by fieldstone or native rock. Fieldstone is typically found in glacial till or outwash deposits and may be available from local gravel pits. Native rock is defined as any material the river would come into contact with during its natural migration within its floodplain, e.g. rock found along or within the bluffs of the river. The native rock must come from sources within or immediately adjacent to the Missouri National Recreational River. The fieldstone or native rock riprap can be used alone. Quarried pink quartzite shall be covered with fieldstone, native rock or a minimum of 12-14 inches of soil from the top of the structure down to the ordinary high water line and covered with fieldstone or native rock from the ordinary high water line (about 45,000 cfs level) to the low, winter flow line (about 15,000 cfs level). The soil requirement allows for the settling of soil into the rocks while still providing an adequate seed bed. A fieldstone or native rock cover is required in the water fluctuation zone (15,000 - 45,000 cfs) because wave action often washes away the soil exposing the underlying material. These practices will maintain the river’s scenic value during normal river flows. Refer to conceptual design drawing below.
2. All riprap materials used shall be clean and free of concrete, metal, plaster, or other non-native materials.
3. Streambank revetment slope shall be designed to provide stability to the fieldstone; estimated to be one foot in height (rise) over a one-foot length (run) or flatter.
4. The soil shall be seeded with a mixture of native grasses and wildflower species and preferably, incorporate native trees and shrubs. Annual rye grass or other cover crop is recommended to reduce soil erosion and enhance the success of the native plantings. Non-native species such as smooth brome and Kentucky bluegrass shall not be used for this purpose.
5. Soil cover and plantings shall be completed immediately upon completion of revetment.
6. Clearing of on-shore and streambank vegetation shall be limited to that which is absolutely necessary for revetment construction.
7. Recommend that any trees or woody vegetation that is removed during rip-rap installation be replaced with native species and increased in quantity.

 

NPS

BURIED REVETMENT- Permit May Be Required

Refers to the placement of material in a trench excavated near the streambank. The purpose of this structure is to allow the streambank to erode to the buried revetment which then becomes the stabilized bank line.

1. Conditions for the riprap revetment apply to this practice.

2. The bottom of the trench should be located below the elevation of the ordinary high water mark to provide sufficient toe-of-slope protection.

3. Once the buried revetment becomes the newly stabilized bank, the permittee may need to re-seed to ensure that native vegetation cover exists from the top of the structure down to the ordinary high water mark.

HARD POINTS: Permit Required

Refers to a wide range of deflective structures designed to force the river current to a different location. This practice is generally prohibited but may be considered on a case by case basis.

WINDROW REVETMENT: Inappropriate Activity

Refers to the placement of material on the streambank. The purpose of this structure is to allow the streambank to erode and launch the piled materials into the river with the intent of stabilizing the bank. This practice is inappropriate and generally ineffective.

BOAT DOCKS

Boat Dock Required Conditions

1. No permanent, habitable, or other structure will be permitted on boat docks or below the ordinary high water mark that will diminish the scenic or recreational values of the MNRR.

2. Floatation systems for boat docks must be comprised of clean (inside and out) sealed containers in sound condition.

3. Damaged docks must be repaired within 15 days or removed from the river to a location far enough away from the upper bank that they will not likely fall in due to bank erosion.

4. Material used for construction (metal, wood, coatings, etc.) must be free from pollutants in toxic amounts (see Section 307 of the Clean Water Act). Visit the Environmental Protection Agency for ideas or information on using Green Building practices.

5. Unless specific circumstances justify it, a dock shall not project more than 25 feet into the river to ensure that the scenic or recreational values of the MNRR are maintained.

6. The permittee shall take all reasonable and necessary precautions to ensure boater safety and prevent interference with general navigation.

7. All dredge or fill activities below the ordinary high water mark require a Clean Water Act Section 404 permit.

If you have any questions regarding this process contact Milton Haar at 605-665-0209.

For information visit the U.S. Army Corps of Engineers Permit Process page.