Natural Channel and Floodplain Restoration, Applied Fluvial Geomorphology
This web site is about using a combination of fluvial geomorphology, hydraulics, hydrology, and aquatic biologic attributes to accomplish natural channel restoration. The Water Quality and Quantity Technology Development Team (W2Q) approach to natural channel restoration is unique in that the planning processes and the practices described herein are based upon restoration alternatives that have been implemented, monitored, and found to be geomorphically self-sustaining (transporting load in stable manner while maintaining the local deposition and scour with naturally stable banks). The geomorphic restoration sites below have been field-checked for response.
If floodplain restoration, channel formative physics, and aquatic assemblages are included in your objectives you are at the right web site. Variations of geomorphic natural channel restoration planning re-establishing floodplain connectivity can occur on wide a distribution of socio-economic landscapes, providing a robust geomorphological analysis is completed and mutual objectives are accomplished. Resources including papers, studies, and presentations are included relevant to a geomorphic approach to natural channel restoration.
The planning paradigm presented here involves a more copious use and understanding of wood in rivers and floodplains while distinctly working with a hydraulic geometry that fits a combination of: current stable analogs, empirical data, and analytical relationships. Streambank stabilization techniques and floodplain re-connectivity are used to establish a foundation to re-establish riparian plant communities with both root matrix and root cohesion characteristics needed for the long term objectives of achieving a natural self-maintaining stream. It is always advised that some level of O&M based on assessment of both geomorphic practices and plant community establishment be included in the early years of geomorphic natural channel restoration, especially with regards to establishing the riparian plant community. State and transition are key attributes to this design approach. Figures 1-4, (14 year old geomorphic restoration) is the first example of this applied approach in a previously incised system. Stream type (Wildland Hydrology, 1994) conversion was F3 -> B4. The South Fork of Asotin Creek Reach at the J-Bar Ranch was installed in 1997. The Frank Koch Reach is located on Asotin Creek, WA.
Alternatives to Traditional Methods
Geomorphic Restoration of an Incised River System South Fork, Asotin, Washington
(Priority #3 Approach*)
Figures 5-9 are an example of a geomorphic restoration of an aggraded longitudinal profile.
Geomorphic Restoration of an Anthropogenically induced Braided and Aggraded River- Asotin Creek, Washington
The geomorphic meander reconstruction restoration of both the J-Bar Ranch and the Frank Koch sites demonstrate the treatment of two stream segments within the same Blue Mountain, WA catchment but with opposite problems, incision (J Bar Ranch) and aggradation (Koch Ranch). Both of these sites are characterized as naturally self-maintaining due to a stable dimension pattern, and profile with well established riparian streambank root cohesion and matrix with re-connected floodplains (BHR< 1.1ft/ft*).
The Bucholz Honey Ranch near Victor, Montana is located along the left bank of the Bitter-root River. July 1, 2008 the Bitter-root River reached a high flow of 8430cfs, 2.3 times channel formative Q. Previous to the July flood event, the left bank shown in Figure 10 was protected with rip-rap. The rip-rap was flanked and consequently peeled away from the bank leaving a highly exposed eroded vertical bank. A toe wood revetment type of floodplain reconnection and bank stabilization was installed in 2008 (Figures 10 through 13). This Bucholz restoration did not include rock components. The cost of the toe wood installation was approximately 32% of the original bank stabilization proposal.
This site remains resilient after exposure to two floods events, 12,400cfs in 2010 and 13,700 in 2011.
The first alternative, which was the re-design and re-establishment of rock rip-rap was estimated to be $250,000 by a private consultant. The final cost of the floodplain (bankfull bench reconstruction), toe wood based design and implementation was $79,000 (Southerland, 2011 interview with Ernie and Myrna Bucholz).
Figure 12 illustrates the components of the toe wood approach developed by Wildland Hydrology which was implemented on the Bucholz Site. The wood toe provides complexity and cover for salmonids. According to the Bucholzs, fly anglers commonly fish his toe-wood reach where they have caught large rainbow trout. The Bucholz live approximately 70 feet from the previously eroded steep bank shown in Figure 10.
Figures 12 through 13 represent one type of toe wood treatment commensurate with streambank stratigraphy and available soil and alluvial material. Based on local conditions, materials available, and objectives other kinds of toe wood based establishment using woody transplants instead of sod mats is shown in Figures 14 and 15.
In coarser low-cohesive soil, such as banks with high sand fraction, the “burrito” shaped soil lift option, as shown in Figure 15, with integrated willow plantings are recommended to establish initial soil matrix stability. Iterations of the amounts and types of soil lift integrated with alluvium and planting placement should be considered, as per sight specific conditions.
As in all practice designs and methods, considerations of dimension, pattern (plan-view) and longitudinal profile is essential. Figure 16 illustrates the placement of sill logs for the lateral stability. On tight radius of curvature turns there is a higher propensity for structural flanking. Toe wood is typically installed at elevations 60 to 70 percent of the bankfull height. The interface between wood and alluvium fill at lower elevations serve a critical need for saturation to counteract wood buoyancy, which varies by species. Wood buoyancy and tightness of curvature (Rc/Wbkf) on the meander bend were found to be principle concerns in Engineered Log Jams. (Southerland, W. B., Reckendorf F. R., and Renner, D., 2011)
The log vane structural choice results in substantial increase in salmonid habitat while providing excellent opportunities for seed recruitment and streambank protection. What is not seen in Figures 17 and 18 are the wood components located below the geo-textile fabric that provides structural support and substantial fish habitat. Wood component could typically include root balls, short root wads, and various sized wood members. Redds are commonly found at the tailout (glide) portion of the pool, Figure 17.
Another highly effective structure, sometimes built with irrigation diversions, is the boulder cross vane or the boulder cross step vane, Figure 19. Figure 20 is a two extra step boulder cross vane with an irrigation diversion on left bank of the Little Snake River in Colorado. Cross vanes or cross vanes with steps on steeper bed profiles are viable design alternatives for vertical control (stabilizing beds from tendency to incise). Step vanes have been used successfully to aid in fish passage for some species.
Combinations of “W” shaped weir structures can be used to accommodate cellular flow into bridges with multiple support buttresses or on wider rivers where invert control (bed elevation control) is needed (Figures 21 & 22). “W” weirs can also be built to accommodate diversions. A more in-depth explanation of vane designs is available in “Cross Vanes, “W” weirs, and J-Hook Vane Structures Updated 2006 (Rosgen, 2006)
Channel incision occurs both naturally and anthropogenically. Throughout vast locations in the U.S. and other countries, anthropogenically induced incision results in floodplain loss or less connectivity. The depth-to-shear component of hydraulic forces increases substantially at higher stage discharges resulting in rapid channel incision. The results of incision can have insidious consequence impacting the physical, biological and sometimes the chemical function of a natural channel. The Schumm Channel Evolution Model provides an invaluable tool that characterizes the incision (aka degradation) process. Another tool, consistent with channel evolution process is the WARSSS Channel Succession Scenarios as described in Watershed Assessment of River Stability and Sediment Supply (WARSSS) 2nd Edition, Rosgen, D.L. (2009). The WARSSS Channel Succession Scenario provides additional information regarding stage and transition. Not all channel succession scenarios are incision.
In geomorphic based meander reconstruction, the choice and utilization of bank and bed stability structures are considered only after system design (natural channel design process) is complete. The choice and locations will depend on a variety of common factors including (not all-inclusive):
placement on the meander geometry,
fish habitat, native plant re-establishment,
width of reconstructed floodplain,
stream channel confinement,
geomorphic valley type,
cost and feasibility analysis,
appropriate elevation relative to the bankfull stage,
socioeconomic position on the landscape, and others depending on resource problem and objectives.
This website is not a personal endorsement of any specific entity or individual. Project sites were identified and chosen on the basis of;
consistent performance defined as meeting objectives,
subject to post flood,
access to on-site technology investigation and development activities
geomorphic restoration with a restored or re-activated floodplain component.
Materials and illustrations from Wildland Hydrology are only used with expressed consent.
The USDA-NRCS-Water Quality and Quantity Technology Development Team offer a series of five courses to train personnel in Geomorphic Stream Restoration and Floodplain Connectivity. They are:
(These are ongoing activities of the W2Q Team.)
Net Training power point on Principles in Fluvial Geomorphology
Stream Geomorphology an its basis for Ecological Site Description
Introduction to Fluvial Geomorphology: Course I
Applications in Fluvial Geomorphology: Course II
Tools in natural channel geomorphic-based restoration planning, design, and wood applications: Course III
Integrating Design Principles, Bedload Transport, and Riparian Planting Re-establishment into Natural Channel Design: Course IV.
Implementation of Geomorphic Structures: Course V
Courses taught when they are open:
Fluvial Geomorphology Courses Recently Completed and Scheduled:
For additional information regarding this site please contact:
W. Barry Southerland, Ph.D.
Fluvial Geomorphologist, CPESC#514
WQQT-West National Technology Support Center
USDA-Natural Resources Conservation Service
1201 NE Lloyd Blvd, Suite 1000
Portland, OR 97232
Baldigo, P. B., D. R. Warren, A. G. Ernst, C.I. Mulvihill (2008) . “Response of Fish Populations to Natural Design Restoration in Streams of the Catskill Mountains, New York” North American Journal of Fisheries Management 28:954-969.
Rosgen, D.L. (2006). Cross Vanes, “W” weirs, and J-Hook Vane Structures Updated 2006, Wildland Hydrology Inc., Fort Collins, CO.
Southerland, W. B. (2011). Personal conversation and on-site review in Victor, MT with Ernie Bucholz, 10-28-2011.
Southerland, W. B., F.R. Reckendorf, D. Renner (2011) Post Project Appraisal of Engineered Log Jams in Washington State, International Symposium on Erosion and Landscape Evolution,American Society of Agricultural and Biological Engineers Held in conjunction with the Annual Meeting of the Association of Environmental & Engineering Geologists, Anchorage, Alaska, September 18-21, 2011.
Southerland, W. B., and F.R. Reckendorf (2009) Post Project Appraisal of Engineered Log Jams in Washington. 2nd Joint Federal Interagency Conference: 9th Federal Interagency Sedimentation Conference & 4th Federal Interagency Hydraulic Modeling Conference,Proceedings of the Ninth Federal Interagency Sedimentation Conference, Las Vegas, NV, June 27th-July1st, 2011.
Leopold, L. B. (1997). Let the River Teach Us. Stream Notes. Fort Collins, CO Stream Systems Technology Center:3.
Leopold, L.B. (1994). A view of the river. Cambridge, MA, Harvard University Press.
NEH 654 (National Engineering Handbook) Chapter 11, Stream Restoration Design National Engineering Handbook (210-VI-NEH). Washington, D.C.: USDA Natural Resources Conservation Service.
Rivermorph, L. L. C., Stantec 2012. Rivermorph Stream Restoration Software. Louisville, KY
Rosgen, D.L. (1996). Applied River Morphology. Pagosa Springs, CO, Wildland Hydrology.
Rosgen, D.L. (2009). Watershed Assessment of River Stability and Sediment Supply (WARSSS) 2nd Edition, Wildland Hydrology Inc., Fort Collins, CO.
Schumm, S.A. (1973). River Morphology: Benchmark Papers in Geology. Dowden, Hutchinson and Ross Inc. Stroudsberg, Pennsylvania.
Schumm, S.A. (1984). INCISED CHANNELS Morphology, Dynamics and Control. Water Resources Publications. Chelsea, MI.
ELJ Pdf power point
Toe wood short report
Hoags 5 riparian zones with hyporeic