[Federal Register: November 17, 2005 (Volume 70, Number 221)]
[Notices]
[Page 69732-69733]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr17no05-27]
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DEPARTMENT OF AGRICULTURE
Natural Resource Conservation Service
Finding of No Significant Impact for Silt Salinity Control
Project, Garfield County, CO
Introduction
The plan/environmental assessment was developed under the authority
of the Soil Conservation and Domestic Allotment Act of 1936. Funding
for implementation is expected to be provided under the Federal
Improvement and Reform Act of 1996, Public Law 104-127, as amended;
Food Security Act of 1985, Subtitle D, Title XII, 16 U.S.C. 3830 et
seq. An environmental evaluation was undertaken in conjunction with the
development of the watershed plan. This evaluation was conducted in
consultation with local, State and Federal agencies as well as with
interested organizations and individuals. Copies of the Plan/
Environmental may be obtained by contacting Allen Green, Colorado State
Conservationist at the following address. Data developed during the
environmental evaluation is available for public review at the
following location as well: U.S. Department of Agriculture, Natural
Resource Conservation Service, 655 Parfet St., Lakewood, Colorado
80215-5517.
Background
The Silt unit was not identified by name in Title II of the
Colorado River Basin Salinity Control Act, but was identified by USDA
as an area which should be studied for possible salinity control.
The combined environmental assessment has three major components:
(1) To determine the contribution of salt loading from the irrigated
farmland; (2) to determine the opportunity for USDA to reduce salt
loading through improvements in irrigation delivery and application
systems; (3) to determine environmental effects of the proposed action.
Approximately 7,430 acres can be irrigated in the Silt Unit by five
irrigation ditches. One of the aspects of the environmental evaluation
involved inventorying and analyzing current irrigation systems and
management practices. Data was analyzed on the five irrigation ditch
systems. Each of the systems was analyzed to determine what types of
improvements are needed. The remaining ditches were not studied because
they are small or no longer in use.
The Wasatch Formation, a claystone shale marine formation with a
very high salt content, underlies much of the valley and is the
principal source of salt contributed to the Colorado River. Lenses of
crystaline salt often are exposed during excavation into shale. Because
of the arid climate, salts have not been leached naturally and applying
excess irrigation water to the soil greatly accelerates the leaching
process.
The Silt Unit contributes approximately 24,700 tons of salt
annually to the Colorado River based on the 17-year USGS record of
volume and concentration of outflow, minus volume and concentration of
inflow. The 17-year record spans a good representation of dry and wet
years. Approximately 14,030 tons come from irrigation practices, and is
in the middle of the range of values used for the seven salinity
project areas e.g. Grand Valley, Colorado; Lower Gunnison, Colorado;
Mancos Valley, Colorado; McElmo Creek, Colorado; Uinta Basin, Utah;
Price-San Rafael, Utah; and Big Sandy River, Wyoming. The remaining
10,670 tons represents salt produced from natural sources. Salt loading
estimates include approximately 4,160 tons from ditch seepage and
approximately 9,870 tons from on-farm deep percolation of irrigation
water.
The proposed alternative plan contains structural and management
improvements to irrigation systems which will in turn reduce salt
loading to the Colorado River by 3,990 tons.
Consultation-Public Participation
The Bookcliff Conservation District led the public participation
process, which included several Public meetings. Public involvement
primarily consisted of meetings; however, local newspapers were used to
publicize the project. Several State and Federal agencies were
consulted during project plan development.
[[Page 69733]]
Proposed Action
The proposed action will result in reducing seepage from the
lateral ditches and increasing the irrigation efficiency to reduce deep
percolation on 2,800 acres.
This action will consist of piping or concrete lining 45,000 linear
feet of earthen irrigation ditches. On-farm irrigation improvements
would consist of improved surface application systems and sprinkler
irrigation.
The estimated total construction cost for the pipeline and
sprinkler systems is $3,546,000. The total estimated project cost is
$4,964,400. It is recommended that the federal cost-share used to
implement the plan not be greater than 75 percent. A cost effectiveness
analysis was used to determine the annual cost per ton of salt
reduction.
Basic Conclusions
The conservation treatment associated with the proposed action will
not change the air quality or potable water quality of the area. The
project will not create any new hazards to the transportation network
within the effected project area. For these reasons it is felt that the
public health and safety conditions of the effected area will not be
significantly impacted.
There are no known unique geographic features in the project area
that could be impacted by the proposed action.
During the inter-agency review process of the project plan no
highly controversial effects were identified.
Past experience with similar projects in the area provide a high
degree of confidence in the predicted impacts of the proposed actions.
This project is not unusual in nature and is quite similar to a
project currently being implemented in Mesa County. For this reason we
feel confident that no precedents are being set with this project.
No significant individual or cumulative effects to the human
environment are expected when considering the context and intensity of
the proposed action.
Our project investigations did not identify any cultural resource
sites currently listed on the National List of Historic Places. In
light of this, the proposed action will not impact any such sites.
Threatened and endangered species habitats do exist within the
project boundaries. The proposed treatment will not change the extent
or composition of this habitat therefore no impact is anticipated.
Communications with State and Federal natural resource management
agencies did not reveal any violations of any laws, including the
National Environmental Policy Act.
Many of the wetlands in the project area are ``irrigation
induced.'' A minimal number of these acres would be impacted. Wetland
functions for the majority of these are already impacted by the land
use associated with them. The distribution and size of these wetlands
is not likely to change.
The water quality of the Colorado River will be enhanced due to a
reduction in salt loading from agriculture.
The agricultural producers participating in the project will
benefit from the labor savings associated with implementation of
improved on-farm irrigation application systems.
Ultimate Conclusion
I find that the proposed action is not a major Federal action
significantly affecting the quality of the human environment.
Dennis Alexander,
Assistant State Conservationist-Programs.
[FR Doc. 05-22809 Filed 11-16-05; 8:45 am]
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