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<br />SUMMARY
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<br />A. Selected Plan
<br />
<br />The Narrows Unit is a multipurpose reservoir development which will provide supplemental irrigation
<br />water, flood control, recreation, fish and wildlife development, and municipal and industrial water
<br />supplies in northeastern Colorado.
<br />
<br />The project would make available on the average 154,100 acre-ft (190 x 106 m3) [30,700 aore-ft
<br />(38 x 106 m3) Weldon Valley right plus 99,500 acre-ft (123 x 106 m3) Narrows Reservoir
<br />yield plus 23,900 acre-ft (29 x 106 m3) divertable return flow] of supplemental irrigation
<br />water annually for 166,370 acres (67,356 ha) in the LSPWCD (Lower South Platte Water Conservancy
<br />District) and for 120,700 acres (48.866 ha) in the CCWCD (Central Colorado Water Conservancy
<br />District). The dam would be an earth embankment structure with a height of 133 ft (40.5 m), crest
<br />length of 18,000 ft (5.486 m). and a crest width of 30 ft (9.1 m). At the top of the conservation
<br />pool, the reservoir would have a length of 13.5 mi (21.7 km) and a shoreline of 36.5 mi (58.7 km).
<br />At the top of the minimum pool, the reservoir length would be 6 m; (9.6 km). Under normal opera-
<br />tions, the Narrows Reservoir would begin filling in November and continue into spring. Water
<br />releases for irrigation would begin in late spring and cause drawdown of the reservoir through
<br />summer into early fall. Reservoir levels would have an average annual fluctuation of approximately
<br />8.6 ft (2.6 m) with a maximum of 44.7 ft (13.6 m). The conservation pool will have a surface area
<br />of 13,189 acres (5.340 halo Ouring drought periods, the reservoir would be drawn down to the top
<br />of the inactive storage pool. A total of 21,035 acres (8,516 ha) of land and water surface will be
<br />made available to the Colorado Division of Wildlife for wildlife management areas. Of that total,
<br />6.758 acres (2,736 ha) will be acquired in fee specifically for wildlife mitigation. Wildlife
<br />management areas, to be managed by Colorado Division of Wildlife, [6,758 acres (2,736 hall are to
<br />be developed according to the general management plan, as provided in sections 3 and 4 of the Fish
<br />and Wildlife Coordination Act (48 Stat. 401) as amended. A warm-water fish hatchery and cold-water
<br />rearing unit would be developed directly below the damsite.
<br />
<br />8. Project Impacts
<br />
<br />A detailed discussion of expected
<br />Proposed Act i on. A synops i s of
<br />follows:
<br />
<br />project impacts is presented in the Environmental Impacts of the
<br />the adverse environmental impacts of the selected plan are as
<br />
<br />i'C
<br />'~,..'
<br />
<br />1. Tran'sportation. The relocatIon of 20.3 mi (32.7 km) of Colorado State Highway No. 144
<br />would take place. About 12 mi (19 km) of county roads will be improved and 3.3 mi (5.3 km) of
<br />new county roa'ds constructed. Additionally, 27 mi (43.4 km) of Union Pacific Railroad track
<br />would be relocated.
<br />
<br />2. Relocations. Project construction would cause the abandonment of 21 mi (33.7 km) of 7.2-kV
<br />lines, 42 m, (67,6 km) of 12.5-kV lines, and 11 mi (17.7 km) of 13.8-kV lines. In addition.
<br />10 mi (16.1 km) of buried p.ipel ine belonging to the Kansas-Nebraska Company, 7 mi (11.3km) of
<br />Rural Electric Administration 12,5-kV powerline, and 38 mi (61.2 km) of rural telephone and
<br />toll lines would have to be relocated. The modification of WAPA1s (Western Area Power
<br />AdminIstration) 115-kV Greeley-Fort Morgan transmission line would have to take place near
<br />Bijou Canal, east of State Highway No. 144 and south of Bijou No.2 Reservoir. Ninety miles
<br />(145 km) of domestic water supply pipel ines would be relocated. One fairway and green would
<br />require relocation at the Fort Morgan golf course.
<br />
<br />3. Energi Requirements. The construction of the reservoir would require a substantial
<br />commltmen of fOSSll fuel to run the <construction equipment, vehicles, and heat for the tempo-
<br />rary construction buildings over an estimated 12-year period. It is estimated that 2 Mgal
<br />(7.6 ML) of fuel would be required during construction. In additIon, it is estimated that
<br />40,000 gal (151,365 L) of lubricants, antifreeze. and other petroleum-based products would be
<br />required.
<br />
<br />4. Prime Farmlands. Reservoir development would inundate 5,500 acres (2,227 ha) of sprinkler
<br />and flood irrlgated farmland located adjacent to the South Platte River. Additionally, another
<br />5,500 acres (2,227 ha) of irrigated farmland would be put in the public domain, but crop pro-
<br />duction could continue as part of a management plan.
<br />
<br />5. Cultural Resources. Approximatel y 60 prehistoric and hi storie cultural resource sites
<br />would be inundated by the reservoir. An undetermined number of. cultural resources would be
<br />partially or totally destroyed by construction. An undetermined number of cultural resources
<br />would be adversely affected as a result of recreation activities. A class III survey will take
<br />place prior to construction.
<br />
<br />6. Air Quality. Oust and exhaust emissions from construction equipment would be in greater
<br />concentrat1ons than under "without project II conditions. In general, the area has a high air
<br />quality, which would only be degraded during construction prior to revegetative stabilization.
<br />
<br />7. Water Quality. With the Narrows Unit inplace. the quality of the water would be more
<br />uniform throughout the year due to the regulated riverflow. During construction, an increase
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<br />5-1
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