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<br />4, Please provide a brief narrative description of the proposed project or study including purpose, need,
<br />facilities, and service area,
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<br />Background: Tamarix spp, (tamarisk), is a deciduous shrub/small tree that was introduced to the
<br />western U,S, in the early nineteenth century from Central Asia and the Mediterranean for use as an
<br />ornamental, in windbreaks, and for erosion control. Tamarisk, also known as saltcedar, is well suited to
<br />arid parts of Colorado and has replaced much of the native vegetation along river and stream banks
<br />below 6,500 feet elevation,
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<br />Tamarisk is a tenacious plant that has a deep root system (up to 100 feet) and leaves a salt residue on
<br />the soil surface, These characteristics enable it to quickly replace native riparian vegetation; e,g"
<br />cottonwoods and willows, The resulting tamarisk thickets:
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<br />>- Increase soil salinity, rendering the soil unsuitable for other plants,
<br />>- Have less value as wildlife habitat than native vegetation,
<br />>- Widen floodplains by clogging stream channels,
<br />>- Impact endangered fish by changing stream morphology,
<br />>- Increase fire hazard and intensity,
<br />>- Diminish human enjoyment of and interaction with the river environment.
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<br />While each of these points is important to one or more constituencies, the single most critical problem is
<br />that TAMARISK STEALS WATER by using more water than native vegetation that it replaces, This non-
<br />beneficial user of Colorado's limited water resources dries up springs, wetlands, and riparian areas by
<br />lowering water tables, As tamarisk moves into adjacent upland habitats, it consumes even more water as
<br />it replaces the native grass/sage/rabbit brush plant communities, Based on average water use values for
<br />tamarisk and the native plant species it has replaced, a rough estimate of the non-beneficial consumption
<br />of water by tamarisk throughout Colorado is approximately 170,000 acre-feet of water per year, These
<br />values are above and beyond what the native vegetation would have consumed and represent enough
<br />water to supply upwards of one million people or the irrigation of nearly 75,000 acres of land, And every
<br />year, the problem only continues to get worse,
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<br />The U,S, Department of Agriculture (USDA) has stated that, , , tamarisk infestation has reached
<br />epidemic proportions and is one of the greatest disasters to ever befall native riparian areas in western
<br />United States, The National Invasive Species Council has identified tamarisk as one of its primary
<br />targets, the Colorado Department of Agriculture has listed it on its noxious weed list, and Colorado
<br />Governor Bill Owens has issued an Executive Order to control tamarisk on public lands within ten years,
<br />Although tamarisk is the primary invasive woody plant (the "poster child" of non-native plants) impacting
<br />Colorado's rivers, other plants, notably Russian-olive co-habit with tamarisk and must also be considered
<br />as a part of any riparian restoration action,
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<br />Inventory Need: In Colorado, the area of tamarisk and Russian-olive infestation is estimated to be
<br />approximately 50,000 acres of land, but this is only a rough estimate, A more accurate inventory of
<br />tamarisk and Russian-olive infestation is a crucial element in the development of control plans at the
<br />watershed scale and a determination of its actual impacts, The inventory becomes the basis for project
<br />planning (e,g" cost estimates, resource allocation, priority setting) and tracking the long-term success of
<br />control efforts, For Colorado, a quality inventory will also place the state in a favorable position to acquire
<br />Federal funding for major demonstrations that are likely to be available in 2004-2008,
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<br />Purpose: The purpose of this study is to establish and implement an inventory protocol that provides a
<br />clear understanding of the extent of the problem but is also economical to perform, The Colorado River
<br />and Arkansas River watersheds are identified because they are heavily infested and represent two
<br />distinct topographic conditions - a western slope canyon setting that is predominantly Federal lands and
<br />a front range prairie setting that is predominantly private agricultural lands, The protocols developed
<br />under this study can then be used to generate accurate inventories for the other major watersheds in the
<br />state; i,e" San Juan, Rio Grande, South Platte, North Platte, and Republican rivers,
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<br />Inventory Approach: A more accurate means of inventorying is required to identify location, density,
<br />and maturity of tamarisk and Russian-olive in comparison to native species, This information is essential
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<br />Flood Protection. Water Project Planning and Financing. Stream and Lake Protection
<br />Water Supply Protection. Conservation Planning
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