2008-01-04_HYDROLOGY - M1984108 - Laserfiche WebLink

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mining as well as well. data from. surrounding areas. Below the gravel layer silt type tines exist (5-25'). The underlying bech-ock is 1Vlancos Shale. 2.4 Vegetation Soil and vegeta ion scientist Jeff Hagn performed a vegetation survey on the site in the Summer of 2003. The results can be seen below. In the undisturbed areas, the perennial vegetation consists of the following species and their approximate corresponding percent of canopy cover: Species %~ Perennial Cover Sticky-flowered Rabbitbrush 5% Field Pennycress 2% Sumac 2% Reed Canary Grass 4% Tamarisk. 2% Cottonwoods S% Field Horsetail 1% Russia Wildrye 4% Russian Olive 4% Russian Knapweed 15% Four-wing Saltbush 3% Siberian Elm 1 Bull Thistle 2% Blue iVlustard 1 Nebraska Sedge 1% Yellow Sweet Clover 1% Intermediate Wheatgrass 5% Cattails 2% Streambank Willow 1% Inland Salt~r-ass 6% ~rotal 7o°io Currently, the site has an infestation of knapweed. Primarily this is due to the field being left fallow. However, the disturbance due to mining has also contributed to this issue. The knapweed was treated. in the Fall of 2004. The effect of the treatment will be reviewed in the Spring of 2005. If additional treatment is necessary it will occw- prior to earthwork on the site. 2.5 Surface and llnderg-round Vt/ater The site lies directly adjacent to the Uncompahgre River. This a.nd the irrigated. fields to the west and south cause the water table to be very near the sw~~face. This fact along with the available irrigation water for the site will be utilized to provide the proper conditions for wetland growth. Test wells were dug prior to the survey. These wells were measured during the survey and are included on Map 2. Two ponds exist from previous gravel extraction. The noz-thern pond is reclaimed and shows superb wetland plant growth. The southern pit where gravel extraction has most recently taken place has not been