EIS Arapahoe & Roosevelt National Forest, Pawnee National Grassland

• File Number: 8461.250
• Description: Water Issues
• State: CO
• Basin: South Platte
• Water Division: 1
• Author: USDA, Forest Service, Rocky Mountain Region
• Title: EIS Arapahoe & Roosevelt National Forest, Pawnee National Grassland
• Water Supply Pro - Doc Type: EIS

?- Chapter 3- Affected Environmeni and Consequences
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Effects from Range Management - Livestock grazing can, depending on management system
3 and number of livestock, affect water qualiry. The ioss af streambank protection can increase
? temperatures, reducing habitat for aquatic species. Also, efffuent in the form of fecat coliform
? above State Water Quality Standards can result due to long-term overgrazing of riparian and
? streamside zones.
Healthy riparian zones and streambank vegetation are also important to maintaining the integrity
? of fluvial systems, water quality and aquatic habitat. Channel instability can be an adverse effect
1 of Iong-term livestock overgrazing of the r+parian zone. Effects of this can also include, with
' varying degrees, reduced vigor and density of riparian vegetation, and decreasing the ability of
vegetation to stabilize the banks. Also, long-term grazing can result in streambank trampling,
? which can affect channel stability. With the loss of stable streambanks, habitat for aquatic
? species is diminished.
? Direct effects of any of the alternatives will include utilization of plants by domestic livestock,
? pr+marily cattle and sheep. The effects on vegetation differ by type of domestic livestock, but for
this analysis these differences are not considered. The effects will vary by alternative due to
? differences in numbers of livestock. Implementation of Alternative A will have the highest risk of
? adversely affecting the water resource. This altemative a(lows iivestack grazing to continue at
current levels and existing risks to water quality, stream and watershed health will continue.
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? Alternatives B, C, D, and F project slight(y lower levefs of grazing to occur than Aiternative E, A,
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lar to
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and G. In each of these alternatives, potential adverse effects to the water resources is s
? those under Altematives E, A, and G, but slightly reduced numbers may allow for some changes
? in management of the individual alloiments which would reduce risks of adverse effects to the
stream and watershed potential, and water quality.

? Implementatian of Altemative F would have the fewest impacts associated with livestock
grazing.
? Effects from Recreation Management - The effects of recreation on the watershed and
? surface water resources can be simi(ar to some effects of livestock grazing. Many camping sites,
? both dispersed and developed, are near lakes, reservoirs and streams. Although these are
? desirable locations, repeated use can reduce the health and vigor of riparian vegetation,
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n stream
s ability to mainta
compact soils, both of which can reduce the riparian vegetation
? stability and increase sedimentation.
? Soil compaction is caused by the weight of vehicles and animals on the ground. Soil compaction
? impairs infiltration and plant growth. It is generally more severe on moist or clayey soils and with
? more traffic.
? Erosion and sediment are caused by disturbing soil and concentrating runoff. Excess sediment
impairs aquatic habitat. It is usually more severe when disturbances occur near streams or on
? unstable or highly erodible soils.
S Stream bank damage is caused by foot and wheeled traffic. Overhanging banks can be crushed
? and large amounts of sediment added directly to streams, with resulting damage to aquatic
? habitat. Bank damage is more severe where animals and people concentrate along streams.
? Wetland-riparian damage occurs mostly as ruts and puddles caused by foot and wheeled traffic.
? Surface and subsurface drainage is changed and plant growth may be impaired.
In general, these effects are minimal except at points of concentrated use. Specific problems are
identified and managed at project level analysis.
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Routi Natlonal Forest - E!S (WateNRlpar?an/Wetlands) 3-49