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• Board Meeting Date: 7/11/2007
• Description: IWMD Section - Water Supply Reserve Account July 2007 Grant Allocations
• Board Meetings - Doc Type: Memo

Proposed Scope of Work

Geotechnical Evaluations
Preliminary geotechnical investigations will be performed for Monison Creek Dam. A qualified
Geotechnical Engineer will log all drill holes and test pits. The boring locations will generally follow the
alignment of the centerline of the proposed embankment. Test pit locations will be selected at specific
potential bonow locations within the inundation area as selected in the field by an experienced Geotechnical
Engineer. The District will obtain all required permission for access onto properties before any work is
commenced.

Stream Gaging and Watel' Balance Studies
In order to provide a foundation for the firm yield analysis, the District will model physical yield from the
areas tributary to the proposed Reservoir using a variety of hydrologic analysis techniques. Initially, the
District will characterize the study watersheds using Geographic Infonnation System (GIS) software.
Identify discharge data available for local streams that is collected by the United States Geological Survey
(USGS), the Colorado Division of Water Resources (DWR), and the United States Bureau of Reclamation
(BOR). The available streamflow data will be adjusted for watershed area and watershed elevation in order
to estimate yield from the study basin. The results of this analysis will be refined and validated by
performing a watershed yield analysis with the Subalpine Water Balance Model. The Model identifies
inputs to a watershed (i.e. precipitation), subtracts losses (i.e. evapotranspiration and infiltration), and
assumes the remainder is output (i.e. streamflow). The basin yield model will reflect physical water
availability at the proposed Reservoir site.

Water Quality Sampling and Lab Analysis.
Basic Water Quality analysis including as full suite of State drinking water parameters: general chemistry,
metals, herbicides/pesticides, biological and radiological parameters. Complete a particle size analysis and
flocculation study to detelmine TDS loads and treatment potential of stored water.

Initial Envit'onmental Studies
Wetland Mapping and mitigation concepts, consultation with regulatory agencies, COE, USFWS, USFS,
CDPHE, Routt County, etc.

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