WSP04977

• File Number: 8543.400
• Description: Projects in the Closed Basin Division - Reports
• State: CO
• Basin: Rio Grande
• Water Division: 3
• Date: 3/1/1985
• Title: Draft Environmental Assessment
• Water Supply Pro - Doc Type: EIS

The topography of the property is flat with an elevation of approximately

7,530 feet near the northwest corner. This gradually decreases in elevation

to the south and southeast where the elevation is about 7,525 feet, a'drop of

5 feet. The lowest elevation is adjacent to the Rio Grande (7,520 feet).

Scattered throughout the tract are small, elevated mounds which provide 2- to

3-foot areas of minor topographic relief.

The climate of the area is cool and dry. The Alamosa area has about 7 inches

of total precipitation per year with about 26 inches of snowfall during winter

months. The remaining precipitation occurs during summer afternoon thunder-

storms. Temperatures have been recorded as low as -50. F in winter to a high of

90. F in the summer. Evaporation rates are high and average 36 inches per year.

2. Geology, soils, and minerals. Similar, to the Refuge, the Lillpop

tract lies within the Alamosa-Vastine-Alluvial land association which was formed

during the Pliocene or Pleistocene era. This alluvial formation is composed of

sand, gravel, silt, and clay. Soils on the land are primarily loam soils with

sandy allUVial land immediately adjacent to the Rio Grande.

Hapney loam is the dominant soil of the northern half of section 18. This soil

is somewhat alkaline, has slow permeability, and is generally associated with

rabbitbrush or greasewood stands. Water table depths are generally about

5 feet. The southern half of section 18 and nearly all of section 19 have a

mixture of Alamosa, Arena, Nortonville, and Vastine loam soils. These soils

have moderate to high water-holding capacity, slow permeability, are slightly

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