Save the Date!
EcoStream - Stream Ecology and Restoration Conference
Sheraton Charlotte Hotel, Charlotte, NC
November 17-20, 2014
The Stream Institute is an interdisciplinary applied research program in the Department of Civil and Environmental Engineering; it operates under the direction of Dr. Arthur C. Parola, Jr. The team of graduate and undergraduate students, staff, and faculty who make up the institute represent a wide range of research interests, including stream and watershed assessment, natural channel design and stream and wetland restoration, bridge scour and countermeasures, sediment transport, debris transport and accumulation, fluvial geomorphology, stream ecology, and aquatic and riparian habitat.
The work of the Stream Institute is primarily concerned with the mitigation of human effects on streams, wetlands, and watersheds, with an emphasis on sediment transport theory, the use and development of field techniques to calibrate theoretical and laboratory-based equations, restoration construction and monitoring techniques, and the integration of bridges, culverts, and other water crossings with stream restoration design. Using natural materials and processes and taking into account past and expected future changes in watershed hydrology, restorations return stream systems to conditions that more closely resemble their pre-disturbance habitat and physical form. Stream Institute restoration activities restore the hydrologic function of the stream valley by enhancing, rehabilitating, and/or recreating stream systems so that they are physically and biologically sustainable.
Streams function not only as drainage systems for watersheds; they are also actively evolving systems that moderate the flow of floodwaters, filter pollutants, recycle nutrients to soils, recharge groundwater, support wetlands, and provide habitat for wildlife and aquatic organisms. Thus, effective restoration design must incorporate the interaction of channel hydraulics and stream morphology with ecological functions. Recent advances in the fields of hydraulics, geomorphology and ecology have significantly influenced the approach to stream assessment and restoration techniques. The effective use of these techniques requires detailed physical and biological assessment of stream conditions so that considerations for the complexity and dynamics of natural fluvial systems can be incorporated into channel design.
In addition to the application of fundamental principles of ecology, geomorphology and hydrology, the specific regional characteristics of the stream systems must be incorporated into natural channel design to develop stable streams with improved ecological function and sustainability. Watershed assessment is critical both for the selection of stream reaches that can benefit from restoration and for effective restoration design.
In 2006, the Stream Institute will work with the Kentucky Division of Water (KDOW) to assess a sediment impaired watershed. The deposition of fine-grained sediments in streambeds compromises the integrity of gravel-bed stream habitats and, according to KDOW, is one of the leading causes of stream impairment in the Commonwealth. The institute will assess watersheds to identify sources of sediment being deposited in impaired streams and recommend methods for reducing sediment loads. The institute will also sub-contract with Strand Associates, Inc. to assess a sediment impaired watershed in Oldham County.
In 2005, the Stream Institute worked with KDOW on a US EPA-funded project to complete geomorphic assessments of streams in the Mississippi Embayment physiographic region in western Kentucky. Over the next few years, the institute will continue assessing the geomorphic characteristics of streams throughout the state. As part of the institute’s use and development of field techniques to calibrate theoretical and laboratory-based equations, these regional assessments include development of regional curves. Regional curves are relations, as a function of upstream drainage area, of bankfull width, depth, cross-sectional area, and discharge at a cross section of a stream. Given the strong influence of local climate and geology on stream channel form, regional curves are typically developed with respect to physiographic region. The regional curves provide estimates of expected channel dimensions and bankfull flow for streams in a given physiographic region and are among the most useful practical tools for the assessment of channel stability and habitat. These estimates are also critical for the design of channels for stream restoration projects. Because the geology of Kentucky is highly varied, its characteristics may be found in many other states; therefore, the techniques the institute develops for Kentucky streams will be applicable to many other streams across the eastern and midwestern United States.
In 2006, the institute will work in eastern Kentucky on a similar EPA-funded project with KDOW to examine the geomorphic characteristics of small streams which originate high on the slopes of mountains and typically have drainage areas of less than 1 square mile. Little has been documented about the geomorphic characteristics of these headwater streams, which are being significantly affected by mountaintop mining and road-building activities.
Stream Design and Restoration
Two EPA-funded projects overseen by KDOW and completed in 2004 were the restoration of over 6000 feet of Obion Creek in western Kentucky and the restoration of over 3000 feet of Wilson Creek in Bernheim Arboretum and Research Forest, near Louisville. The Stream Institute designed the restorations for both streams, and the projects garnered significant attention, including coverage by the Associated Press.
The Obion Creek project, a cooperative effort between the Stream Institute and the Obion Creek Watershed Conservancy District, addressed multiple problems arising from the 1930s channelization of a portion of the stream: a 1.5-mile-long debris jam at a bridge, a frequently flooded roadway, massive deposition of fine sediment, dead and dying bottomland hardwood timber, and flooded farmland.
The Wilson Creek project, completed in collaboration with Bernheim, transformed the stream channel from its human-imposed low sinuosity, confined, and relocated bedrock regime to a sinuous alluvial stream position near the valley center. In addition to sediment transport, many other important aspects of stream design were considered to restore riverine habitat. An important restoration design component was the proximity of valley groundwater levels and aquifer thickness to support high-stress period (low flow) pool habitat. The design reconnected the stream, floodplain, and groundwater, created gravel riffles and substrate over the bedrock channel bed, increased pool depth and complexity, and established native riparian zones and wetlands that provide improved sustainable and diverse habitat.
Another anticipated project to be completed with the Kentucky Transportation Cabinet, the Federal Highway Administration, and the US Fish and Wildlife Service (USFWS) in Lincoln County, Kentucky, would remedy the historic straightening and relocation of tributary channels of the Dix River and the drainage of adjacent wetlands. Restoration of the degraded tributaries and their accompanying forested wetlands would improve (1) stream and wetland habitat diversity and availability, (2) habitat connectivity, (3) stream and wetland functions, and (4) connectivity of streams to their floodplains. This project would allow for application of the lessons and techniques of the Wilson Creek restoration to large river floodplains.
Waterway Crossings and Stream Restoration Design
In Knox County, USFWS and the National Resources Conservation Service are investigating the possibility of restoring a degraded stream in which blackside dace, a threatened species, have been found. The targeted stream reach has been channelized and affected by mining, logging, and livestock grazing on adjacent land, all of which have contributed to channel degradation, erosion, and siltation. Not only is the dace habitat severely impaired by the thick layers of silt deposits which coat the stream bed, but the channel is incised so deeply that the culvert crossing the channel does not allow the fish to travel upstream beyond the crossing. Restoration of the channel would allow the Stream Institute to build on the lessons and techniques acquired from earlier projects by incorporating culverts and passage for fish and aquatic organisms into the restoration design.
Urban and Suburban Streams
Stream Institute assessment and restoration projects have been conducted in primarily rural watersheds. Future research projects, however, will include urban and suburban watersheds and the specific challenges they present. Urban and suburban streams are affected not only by current development but also by the land uses associated with their rural pasts. Some preliminary research and investigations conducted by the institute suggest that the effects of agricultural and other land-use practices may be as important as the influences of climate and geology.
In 2005, institute engineers traveled to New Zealand to assist the University of Auckland with the assessment of Auckland streams. In spite of the vast differences in geology between the eastern United States and the Auckland region, engineers found the conditions of streams to be surprisingly similar: like streams in Kentucky and other parts of the eastern US, Auckland streams exhibited signs of having been affected by logging practices, mills, and channel straightening for agricultural and flood control purposes.
The institute was founded in 2004 with a US EPA grant secured with the assistance of U.S. Senator Mitch McConnell. Major cooperative and funding partners for institute projects, in addition to those mentioned above, have included Kentucky Department of Fish and Wildlife Resources and the US Forest Service. Through continued cooperative research projects with international university collaboration and federal and state government agency collaboration, the Stream Institute will continue to expand and improve the techniques and methods used in stream and wetland design and restoration.