Stream Restoration Protocols were created by an expert panel and are used by Chesapeake and Atlantic Coastal Trust Fund. There are five protocols within stream restoration. These practice types require additional inputs in order to calculate the estimated reductions.
This article provides all of the qualifying conditions and input information that you will find in the FieldDoc system when entering your information for Protocol 3. It is provided in order to help you prepare your information during the project set up process.
Find information on each protocol visit their respective articles
Protocol 1 - Prevented Sediment
Protocol 2 - Denitrification in the hyporheic zone
Protocol 3 - Floodplain reconnection
Protocol 4 - Stormwater performance standard
Protocol 5 - Outfall and gully stabilization
And read this article for steps and videos ons how to add your stream restoration practice to your project.
Qualifying Conditions for Denitrification in the hyporheic zone
Project must meet applicable floodplain management requirements in the stream corridor. Any individual stream restoration project should be assessed with hydrologic and hydraulic models to demonstrate whether it increases water surface elevations or has adverse downstream flooding impacts. In general, these analyses are based on design storm events and flood risk conditions established by the appropriate local or state floodplain management agency (e. g., the 100-year storm event).
Project must evaluate the duration of floodplain ponding in the context of the restoration goals. Micro pools and long-duration ponding of water on the floodplain is essential for amphibian habitat, but large open water features may adversely impact the desired riparian vegetative community. In evaluating a potential restoration site and design, consider the potential adverse effects of extended open water ponding based on the soil characteristics, plant community, amphibian and other aquatic habitat goals.
Project must demonstrate consideration of potential unintended consequences of the restoration. The project should document that a site impairment exists and that the interventions or restoration work proposed are appropriate to address the impairment. The proposed design should demonstrate that a positive ecological functional uplift (or change) for the stream and associated riparian system will result.
Project must demonstrate that it either provides, or is tied into existing upstream and downstream grade controls to ensure the project reach can maintain the intended stream access to the floodplain.
Project must clearly define the boundary of the effective hyporheic zone. For Floodplain Restoration and Raising the Streambed projects the effective hyporheic zone is a maximum of 18 inches deep in the floodplain soil profile, and extends only to those areas that are regularly inundated after the streambed is raised. The actual dimensions must be confirmed by site investigations that define stream flow conditions, root zones, aquifer conditions and the pre-project water table conditions.
Project must demonstrate that baseflow conditions are not reduced as a result of the restoration (ex. change from perennial to seasonal intermittent flow).
Presence of legacy sediment deposits or other floodplain impairment. Legacy sediments must be present in the project reach to a depth that has impaired aquatic ecosystem function. Legacy sediment includes any deposits that have occurred since European settlement, including very recent sediment deposits, often created by features such as mill dams, road embankments, floodplain fill and other kinds of stream corridor impairment.
Floodplain connection to valley bottom aquifer. The design objective is to restore a plant/groundwater connection within the floodplain, so that most of the root mass of the floodplain vegetation is in direct contact with the underlying hyporheic aquifer. In cases where the historic hyporheic aquifer cannot be accessed due to modern controls (i.e., culverts or utility crossings), the objective is to plug the flow of the underlying aquifer so as to create a new hyporheic zone using cobbles, gravel and/or sandy materials.
Defined boundaries for the channel(s), floodplain and valley bottom. The restored channel and floodplain dimensions are based on field testing that define the key vertical and lateral sediment boundaries of the existing floodplain and the hyporheic aquifer beneath it.
Removal of legacy sediments is the primary means to restore floodplain reconnection at most sites.
Meet applicable floodplain management requirements in the stream corridor. Any individual stream restoration project should be assessed with hydrologic and hydraulic models to demonstrate whether it increases water surface elevations or adverse downstream flooding impacts. In general, these analyses are based on design storm events and flood risk conditions established by the appropriate local or state floodplain management agency (e.g., the 100-year storm event).