Colorado - Grand County Stream Flow Mgmt Plan Phase III_Application II (3)

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- - Scope of Work 3.1 Conduct Stream Assessment: The project team will conduct a stream assessment of selected project reaches, not to exceed 20 miles total, to establish the current condition of the rivers in terms of geomorphic processes. The investigation will include assessment of factors that contribute to stream health such as bank stability, bed stability, excess sediment deposition, health of vegetation in the riparian corridor, and human influences. Sediment transport analyses conducted for determination of flushing flows (Phase 2) will be considered and incorporated in this phase. Should a specific reach appear, based on visual observations, to be experiencing excessive sedimentation or degradation, a system-wide sediment transport component may be proposed. Basic morphologic characteristics such as gradient, sinuosity, bed material composition, geologic controls, influence of large woody debris (L WD), and level of confmement will be investigated. The assessment will provide a description of the current stream condition as well as identification of stressors or natural factors that have resulted in conditions that are considered to be degraded. The approach for the assessment will involve field observations, and review of available information including maps and aerial photographs. Investigations will include walking the stream, taking notes and collecting photographs to document observations. In order to minimize duplication and field data collection, the PHABSIM sites will be utilized for this effort where available. Reaches with no field data from either previous efforts or from the PHABSIM surveys, will require additional surveyed cross sections. Survey information required for this analysis includes cross sections, bed profiles, substrate information, bank conditions and bed material sampling. For the purposes of this proposal and fee estimate it is assumed that 100 cross sections will be required. The information collected at each reference site will generally follow that described in a "Level II" assessment (Rosgen 1996). The results of the stream assessment will be documented including written descriptions, photographs and mapping as required describing this assessment. 3.3 Conduct Aquatic Habitats Assessment. The goal of this task is to identify opportunities and suitability of reaches, on a conceptual basis, for restoration. This work will be conducted in two phases. First, utilizing available information, characterize existing and historic regional aquatic (channel, riparian and wetlands) habitats. Secondly, the project team will perform a cursory field investigation and qualitatively characterize current riparian types (e.g. shaded-riverine, riparian forest, cottonwood canopy seasonal wetland, etc.) at each project reach, identifying dominant vegetation types such as cottonwood trees, willows, grasses and other ground cover. We will identify habitats in or adjacent to the potential restoration sites that may be subject to regulation under Section 404 of the Clean Water Act if flow regime is altered due to the two Firming Projects, and/or if restoration is to occur. There are two concerns: the first being if restoration projects are implemented, what habitat exists today and can it be improved, and what are the potential permitting issues with restoration. Secondly, are there reaches that may loose riparian vegetation if flows are reduced/groundwater lowered etc. regardless of whether or not any restoration is implemented. This effort will be based on visual observations and will be incorporated into the decision making process for reaches that may be considered for restoration as well as reaches that may be or have been impacted by changes in flow regime and warrant further study. The results will be documented including written descriptions, photographs and mapping as required describing the assessment. Stream Management Plan TETRA TECH ~ Grand County, Colorado 2