by Carolyn Schott, Lifezone Ecological
Abstract: A collaborative partnership is joining forces for watershed planning in the Upper Arkansas River Basin, and a stream restoration pilot project is underway at Hecla Wash within the Arkansas Headwaters Recreation Area (AHRA). The Hecla Wash project aims to implement ecologically sustainable watershed restoration measures to reduce sediment loading and achieve improved water quality and habitat in an impaired reach of the upper Arkansas River. The project is meant to serve as a pilot project for the larger area of interest which includes numerous tributaries within Brown’s Canyon and adjacent reaches. Hecla Wash was selected as the pilot watershed due to the significant sources of sedimentation and water quality impairment. Sediment sources include a county road and vehicular traffic, extremely high recreational use, irrigation structures and spills, historic mining, and some amount of ranching and grazing. Project success will be measured through robust monitoring and evaluation, and should set the stage for additional watershed planning in the basin.
Background: Resource use in combination with reoccurring heavy rainfall events in Chaffee County has caused several ephemeral tributaries AHRA including a tributary, referred to as Hecla Wash, to experience significant erosion and sedimentation problems. Following each sedimentation event, State Parks personnel work to mitigate the most critically impacted areas of the watershed and remove sediment deposits at the mouth of Hecla Wash. The band-aid solutions are quite temporary and do not fully address the problems, nor do they lead to measurable improvements or long term sustainability.
Excessive bed sediments are impacting the stream systems as they influence both physical and biological processes and patterns, such as channel morphology, riparian regeneration, macroinvertebrate abundance, spawning habitat, and groundwater interaction. Too much fine sediment buries the bed of the channel, smothers Brown Trout and fall spawning fish eggs, as well as fills interstitial spaces essential to macroinvertebrate habitat.
A holistic restoration and sediment reduction project is being planned to reduce future threats, lead to improved water quality, enhance ecological functions, maintain recreational use, and show measurable results.
The goal of the proposed restoration and sediment reduction project is to restore and improve the most impacted and degraded tributary in this section of the AHRA. The partnership intends to showcase the restoration efforts as a demonstration or pilot project for numerous other priority tributaries in the upper Arkansas River Basin, and to continue with a larger watershed planning vision for the future.
According to reports from the CO Department of Public Health and Environment, the reach of the Arkansas River between Browns Canyon and Canyon City not only exceeds basic standards for aquatic life for cadmium, zinc, nickel, lead, and copper, but also has sediment cited as a major concern as well.
Existing Information: So far, approximately $100,000.00 have been spent studying the watershed in detail. A stream restoration concept plan and a watershed plan has been produced by a team of environmental professionals who studied such aspects as hydrology, hydraulics, erosion, sediment transport, channel stability, wetlands, wildlife and fishery habitat, T&E species, and other key items.
One of the main causes of environmental degradation at the site is due to problems in the Upper Basin, where significant gully erosion in silty clay deposits appears to be exacerbated by the operations of an irrigation return dump. The second key cause of environmental degradation and water quality problems involves exposed fill banks of the recreation access road leading from U.S. Highway 285 down to the Hecla Junction site. One notable reach of Hecla Wash is directly encroached on by roadway fill, with little to no stabilization in place to prevent erosion and scouring. The third cause for degradation and excess sediment at the site is a high level of human visitation, vehicular traffic, off-road vehicles, pedestrian hiking, and related activities. Lastly, some amount of grazing and historic mining in the basin can certainly add to the metals and sediment loadings.
Final Design: Final design is being completed by qualified engineering firm. Their evaluation of the site will include: hydrographic and topographic survey, wetland delineation, plant species identification, assessments of bank stability and geomorphic processes, surface pebble counts, subsurface volumetric sediment samples, and identification of the physical characteristics. Hydrographic survey data will be used to calibrate hydraulic models for analysis and design. Surface and subsurface sediment data will be used to estimate soil parameters needed for modeling. This data collected will provide a basis for planting plans and greater understanding of site conditions.
Project Implementation: The project sponsor recently leveraged money from a flood insurance settlement as matching funds and the partnership received conditional approval of an EPA 319 grant application request for $325,000.00. A Project Implementation Plan is currently being developed and on-the-ground work is scheduled to begin in fall 2008.
Public Involvement: A component will be used to nhance public understanding of the project and encourage their early and continued participation in selecting, designing, and implementing the management measures that will be implemented. The AHRA Citizens Task Force has been functioning since 1990 as an advisory group to the BLM River Manager and the State Park Manager.
Watershed Vision: The project aims to improve the health of the watershed and demonstrate a proven ability by the project coalition to accomplish future similar projects. The project success will be evaluated and measured for a minimum of five years following implementation through a collaborative effort utilizing resources from several of the project partners. Measurements and success criteria will include channel stability, cross-sectional data, sediment movement, water quality, post-flow forensic evaluations, and instrumentation in the Arkansas River. Monitoring efforts will also include wildlife and fishery habitat analysis, integrated resource management, and other components.
Partnership: The sponsor for this project Colorado State Parks, Arkansas Headwaters Recreation Area. Partners include: AHRA Citizens Task Force, Bureau of Land Management, Chaffee County, Colorado Division of Wildlife, Colorado Mountain College, Colorado Water Conservation Board, Greater Arkansas River Nature Association, Natural Resource Conservation Service, Sangre De Cristo Resource Conservation & Development Council, and Trout Unlimited.
For more information about this project, please contact Carolyn Schott. Phone (970) 531-2453 Email: email@example.com