2003-01-06_REVISION - M1992016 (2)

Home Browse Search

r~ 2. Soils Map I7nits - A Soils map with descriptions of soils is attached. There are 15 identified soils on the unit. The map unit description shows information on horizon textures, pH range and salinity class range. Rangeland Productivity -Attached is a portion from table C1 for each soil. The ecological site is shown on each map unit description. Example: Riverbottom #73 4. Construction Materials -Table ENG-1 (attached) is from the County wide soil survey. The table indicates probable sources of gravel and sand for each soil. Most of the soils are shown as "poor" sources for sand and gravel. However, the soil survey maps materials to only 60". Often gravels are present at or just below 60". The numerous recently excavated test holes should be reliable for on site information. Most of the soils have sufficient depth (3' +) to provide soil back-fill and topping for later reclamation. 5. Vegetation Inventory - A vegetation inventory was made 4/4/02 on the several ecological range sites on the unit. The following plants were identified in descending order by percentage present: • Map unit 67, Manvel silt loam, Salt flat range site: Alkali sacaton grass, Winterfat shrub, Indian ricegrass, shadscale shrub, Pearly mockheather shrub and numerous native annual weeds. • • Map unit 72, Midway - Cascajo; Gravel Breaks range site; Needleandthread grass, Indian ricegrass, blue grama, 3-awn, sideoats grama, sand dropseed, ring muhly. Lesser amounts of annuals, cacti and yucca. 6. Reclamation Recommendations -Here are suggested operations toward the reclamation and revegetation of sites most likely to be excavated for gravel mining after the close of mining operations. Pre-mining -Strip and stockpile all the original topsoil for later replacement. Post Mining - 1) Smooth down all hummock, waste piles and swales. Compact fills to prevent further settling. Where possible the fmished grades should blend in with the surrounding topography. 2) Re-spread the stockpiled topsoil back over the mined and disturbed areas. At least 12" of soil is needed to support young seedlings. Revegetation success can be further enhanced by construction of small depressions commonly called "dozer basins". These depressions are usually made with a dozer or loader when grading is finished. They are generally about 15' x 20' in size and 12" to 15" in depth with sloping siderolls to permit grass drilling, scattered over the reseeding area. These basins will catch and hold water for a few days and also provide water storage during snow melt. r 1 U CONSERVATION -DEVELOPMENT- SELF-GOVERNMENT