Abstracts: Aquatics and Marine Ecosystems
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Culvert Test Bed: Fish-Passage Research Facility
Walter Pearson (Phone: 360-681-3661, Email: email@example.com), Associate Director, and
Christopher May (Phone: 360-681-4556, Email: ), Senior Research
Engineer, Marine Sciences Laboratory, 1529 West Sequim Bay Road, Sequim, WA 98382,
The passage of juvenile salmonids and other fish through culverts is a significant Endangered Species Act (ESA) issue throughout the Pacific Northwest and now in other areas of the nation. Much of recent research and engineering has focused on increased passage of returning adult salmon; however, juvenile-salmonid movement both up and downstream throughout the year is now recognized as substantial and is a key area in which future research promises practical returns. Because a large percentage of the culverts beneath roads in the Pacific Northwest are judged as blocking juvenile salmon from thousands of miles of habitat, determining appropriate hydraulic and fish-passage designs for retrofitted culverts before installation has both substantial cost and environmental implications.
To address these issues, the Washington State Department of Transportation (WSDOT) leads a partnership that includes the Washington Department of Fish and Wildlife (WDFW), Alaska Department of Transportation, Alaska Department of Fish and Game, Oregon Department of Transportation, California Department of Transportation, the Federal Highway Administration, and the Pacific Northwest National Laboratory (PNNL). The partnership has undertaken a phased program conducted by an interdisciplinary team of scientists and engineers from PNNL to address the hydraulic and behavioral issues associated with juvenile-salmonid fish passage through culvert systems. This program addresses the testing and assessment of full-scale physical models of culvert systems deployed in an experimental test bed. Experiments in the test bed have begun and will measure the hydraulic conditions (mean velocity, turbulence, and water depth) associated with various culvert designs under various slopes and flow regimes, and then relate these measures to repeatable, quantitative measures of fish-passage success.
The culvert test-bed program is a one-of-a-kind capability designed to provide scientifically sound information that can be used to develop better designs for retrofitted culvert installations. Compared with field studies or temporary installations, the facility promises fast results, scientific and statistically controlled evaluations, an ability to quickly discern optimum engineering principles, and elimination of expensive trial-and-error approaches of field installations.
Engineered Logjams: An Alternative Bank-Protection Method for US 101 Along the Hoh River, Washington
Carl Ward (Phone: 360-570-6706, Email: WardC@wsdot.wa.gov), Regional Biologist/Olympic Region Biology Program Manager, Washington State Department of Transportation, P.O. Box 47417, Olympia, WA 98504-7417, Fax: 360-570-6697
The Washington State Department of Transportation (WSDOT) has repetitively made emergency scour-damage repairs along US 101 at the location on the outside of a meander bend in the channel-migration zone of the Hoh River near Forks, Washington. Four emergency projects that involved armoring the bank with large volumes of rock occurred at this location in the past few years, yet erosion continued and US 101 remained in imminent danger of being washed out.
Engineering analysis conducted by WSDOT indicated that relocation of the highway further from the channel-migration zone was economically infeasible. Therefore, bank-stabilization and river-deflection measures to protect the roadway were the only viable option. Because the "traditional" repairs were not effective, WSDOT developed an alternative solution for the site using engineered logjams (ELJs) in place of armoring bank-stabilization methods. The project has the added benefits of restoring salmon habitat and proving that sustainable engineering is not only possible, but can at times provide the most practical long-term solution.
ELJs emulate historic conditions and natural processes to rehabilitate aquatic and riparian habitat; provide erosion control, flood diffusion, and grade control; and increase sediment retention. Engineered logjams are an emerging technology based upon the premise of applying rigorous scientific and engineering principles to the design and construction of structures to protect infrastructure in a manner that emulates natural systems.
The Hoh River engineered-logjam project is the largest engineered-logjam project in the Pacific Northwest, and possibly the world. A series of 12 mid-channel and bank structures were installed. This action was intended to deflect and diffuse river flows to reduce the erosive forces acting upon the bank adjacent to the highway, as well as provide greater separation of the river from the highway shoulder.
The mid-channel logjam structures each include more than 100 logs (many with rootwads) with key log diameters of 36 to 48 inches. The core of each structure consists of steel H-piles, 65 logs, and 2,200 tons of rock. Each mid-channel structure is approximately 30 feet in height, 75 feet wide, and 70 feet long, with approximately 15 feet of the structure buried below the riverbed level. The structures include several large protruding logs that are used to hold smaller racked logs in place forming irregular faces. Exterior racked logs and naturally accumulating woody debris are key for complex habitat formation.
The design life of the engineered logjam structures is expected to be a minimum of 50 years. These structures will provide stable hard points that deflect river flow and provide a medium for the growth of native vegetation on logjam islands in the channel, while emulating natural logjams in many pristine river reaches in the Pacific Northwest.
The project was designed in the spring of 2004 and constructed from early July through mid-October 2004. Significant difficulties with the temporary river diversion, water-quality maintenance, and fish handling occurred during construction. Although winter flows have been lower than normal in this first year, indications are that the structures are performing as desired.
Environmental Retrofit for Highways: Making Wildlife a Priority
Paul Wagner (Phone: 360-705-7406, Email: firstname.lastname@example.org), Biology Branch Manager, Washington State Department of Transportation, Environmental Services, P.O. Box 47331, Olympia, WA 98504, Fax: 360-705-6833
The environmental aspects of transportation projects have typically focused on the avoidance and minimization of impacts and compensatory mitigation for unavoidable impacts. Recently, progressive transportation agencies have been expanding beyond the primary focus of project effects and evolving toward a more thorough integration of environmental stewardship in their actions. Agencies are beginning to integrate environmental factors into transportation planning and are also providing environmental enhancements as part of projects when opportunities arise.
Transportation agencies have traditionally prioritized their work to meet the typical infrastructure needs for addressing deficiencies and making improvements for safety, capacity, and system efficiency, as well as upgrading aging facilities. Significant environmental improvements can be reached using good stewardship practices in planned transportation projects. However, sometimes areas with ecological needs do not coincide with areas needing transportation infrastructure improvement.
How can transportation programs move beyond the project and permit perspective and work to address ongoing ecological issues and thus provide larger environmental gains?
One approach is the Environmental Retrofit Program developed by the Washington State Department of Transportation (WSDOT). This program is designed to identify environmental deficiencies within the highway system and address them both as parts of planned transportation projects and also as stand-alone environmental-retrofit projects. These standalone retrofit projects may be conducted not only where the transportation needs are currently satisfied, but where significant ecological impacts exist. The focus areas for this program are based on the ecological priorities, including fish-passage correction, stream-habitat restoration, and water-quality improvements.
An example of the benefits of this program can be seen in fish passage retrofit activities. Culverts at road crossings that block fish movement are recognized as a significant conservation issue, particularly for anadromous salmonids, many of which are listed under the federal Endangered Species Act (ESA).
Since 1991, the Fish Passage Retrofit Program has been managed cooperatively between WSDOT and the Washington State Department of Fish and Wildlife (WDFW). Over 5,000 stream crossings have been inspected on the state highway system. As a result, over 800 culverts have been identified that block significant habitat upstream and are targeted for correction. Over $26 million has been invested in inventory, design, and construction for stand-alone retrofit projects that restore fish passage at 59 high-priority sites.
As a result, access to over 400 linear miles of salmonid habitat, once blocked, has been improved. This presentation will discuss how the program operates, as well as specific examples of the projects that have been implemented.
The main components for operating this program include: Definition of the problem and parameters; Field Inventory and survey; Statewide prioritization, based on ecological gain; Scoping of project corrections; Design development; Permitting; Construction; Monitoring; Research; and Coordination and partnerships.
The concepts of this program are now being expanded to address other types of aquatic-habitat issues though identification of what is termed chronic environmental deficiencies (CED) and stormwater treatment needs. Future applications of this program are being developed to address priorities for terrestrial habitat-connectivity improvement. This is a successful program with tangible benefits on the ground that demonstrates how transportation agencies can play a meaningful role in ecological-restoration efforts.
Restoration of Aquatic Habitat and Fish Passage Degraded by Widening of Indian Highway 58 in Garhwal Himalaya
Ramesh C. Sharma (Phone: 91-1370-267740, Email: email@example.com), Professor and Head, Department of Environmental Sciences, H.N.B. Garhwal University, Post Box 67, Srinagar-Garhwal 246174, Uttaranchal, India
Sustainable approaches to the construction and widening of roads and highways are essential to offset negative influences on aquatic habitat and fish passage in the fragile ecosystem of the Himalayan Mountains in northern India. Evidence is growing that the expanding, poorly designed network of roads and trails in mountain areas, without giving due considerations to natural processes such as geological processes and climatic severity, such as heavy monsoon precipitation, is a major cause of habitat fragmentation and degradation of both terrestrial and aquatic habitats.
These effects have been quantified for aquatic primary producers (periphyton), aquatic benthic insects, and Snow Trout, a Himalayan teleost (Schizothorax richardsonii, Gray; Schizothoraichthys progastus, McClelland) that dwells in the upper Ganges River, following Indian National Highway 58 (NH-58) in the mountain region of Garhwal Himalaya, India (latitude 29 degree 61 minutes -30 degree 28 minutes N; longitude 77 degree 49 minutes -80 degree 6 minutes E). Indian Highway 58 is one of the most important highways, is 300-km long, and passes along the Alaknanda River (230 km), which is one of the parent streams of the Ganges (70 km) in the fragile mountain ecosystem of Garhwal Himalaya of northern India. Keeping in mind the heavy traffic on the highway, a RS 450 million (US $100 million) widening project was launched in 2001.
The widening of Highway 58 through massive cutting of mountain slopes, the disposal of tons of the cut material downhill into the waterways in an uncontrolled manner, and the improper water management of the slopes has resulted in intensive accumulation of soil and woody debris into the aquatic ecosystem from accelerated erosion, gulling, and landslides, resulting in drastic changes in the physico-chemical and biological profile of the aquatic habitat. Detrimental effects on transparency, current velocity, conductivity, bottom-substrate composition, dissolved oxygen, periphytonic production, and the production of benthic insect communities have been documented. Feeding, spawning, and the passage of the Snow Trout cold-water fish have been degraded or destroyed.
Subsequent to the widening of Highway 58, the annual gross primary production (Pg) of periphyton declined from 8771 g C m-3yr-1(96.48 k. cal m-3yr-1) to a value of 5952 g C m-3yr-1 (65.47 k cal m-3yr-1), a 32-percent decrease in aquatic habitat. The maximum biomass (standing crop) of aquatic insects declined from a mean monthly biomass of 4.926 g m-2 (February) to 1.848 g m-2, a 62-percent decrease, and a minimum monthly mean biomass of 0.408 g m-2 (August) to 0.126 g m-2, a 69-percent decrease. Subsequent to widening of the highway, the standing crop estimate of Snow Trout declined from a maximum mean monthly biomass of 2.955 g m-2 (February) to 1.201 g m-2, a 59-percent decrease, and a minimum monthly mean biomass (August) of 0.244 g m-2 to 0.082 g m-2, a 66-percent decrease. Annual productivity of Snow Trout declined from 1.309 g m-2 to 0.448 g m-2, a 66-percent decrease.
This decline is believed to have been caused by increased turbidity accompanied by a decline in depth and dissolved oxygen, accumulation of fine silt and suspended solids, a decrease in primary productivity, a decrease in general benthic-aquatic insects productivity, depletion of the food supply, and loss of cover.
The Role of Geomorphic River Reach Assessments in Developing Environmentally Beneficial Highway-Protection Measures
Jennifer Black Goldsmith (Phone: 206-441-9080, Email: firstname.lastname@example.org), Senior Scientist, and Tim Abbe (Phone: 206-441-9080, Email: email@example.com), Director of River Science and Geomorphology, Herrera Environmental Consultants, Seattle, Washington 98121, Fax: 206-441-9108; and Jim Park (Phone: 360-705-7415, Email: firstname.lastname@example.org), Floodplain Management Specialist, Washington State Department of Transportation, P.O. Box 47331, Olympia, WA 98504-7331
Historic highway placement within river valleys has commonly occurred within flood and erosion hazard areas. Traditional maintenance of highways and other infrastructure in these environments can be costly, result in significant environmental impacts, and exaggerate risk elsewhere. Many rivers are subject to frequent changes in position as they migrate within their valleys. This channel migration is not limited to low-lying land subject to frequent flooding, but can consume new areas where the river has not historically been.
Changes in channel geometry alter flow conditions that can lead to either degradation (down-cutting) or aggradation of the river. Degradation can undermine road grades and bridge abutments and piers. Aggradation can increase flood frequency. Chronic maintenance and emergency repair are expensive and often do not address the source of the problem, but rather address the effect the flooding and erosion is having on the highway and related infrastructure. Furthermore, these measures rarely address impacts to habitat or how habitat can be improved from a proposed project.
Conducting a "geomorphic reach assessment" of a river's processes and dynamics can be a valuable management tool for highway maintenance and operations managers to better understand why maintenance measures are chronically failing and to minimize emergency response by assessing potential near-term river hazards that may pose a threat to a highway and infrastructure. Geomorphic assessments evaluate historic channel dynamics, current river conditions, and hydrologic characteristics of the river system.
These assessments can also include conceptual designs and recommendations describing how to protect the highway from flooding and erosion, as well as improve existing habitat that may have been historically compromised because of highway placement and maintenance.
The results of a geomorphic assessment provide useful scientific information that is used in developing effective design solutions that address the flooding and erosion problems associated with a highway in a manner that does not compromise habitat, but instead actually improves current habitat conditions.
One such emerging technology that was developed in the Pacific Northwest is the use of "engineered logjams" for highway and infrastructure protection with the secondary benefit of improving aquatic habitat. Logjams can increase pool frequency, channel length, and riparian cover, as well as provide necessary bank protection for highways located along actively eroding banks. However, these technologies reintroduce natural complexity and variability to the river system. An analysis of how these structures could potentially alter flooding and erosion within a reach needs to be assessed for individual site scenarios.
We present several examples of reach assessments conducted for the Washington Department of Transportation to provide a better understanding of highway segments with chronic problems and outline better long-term maintenance strategies that enhance habitat recovery. This approach was utilized in the implementation of a complex engineered logjam (ELJ) project that has successfully protected U.S. Highway 101 and created valuable new aquatic habitat in the Hoh River of western Washington.