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Page 3 Jim Monroe Patterson Pass Business Park A comprehensive delineation of the site was conducted on March 17, 1998. Five separate potential wetland areas were identified; Patterson Run (Sheet 3), Area C (Sheet 3), Drainage A (Sheet 3), Drainage B (Sheet 4), and a pond (Sheet .4). Each of these areas will be discussed separately. WETLAND DELDTEATION RESULTS Patterson Run Paterson Run is an intermittent ephemeral drainage, varying in width from 14 to 56 feet, which nieanders from southwest to northeast across the site. . This drainage flows from a culveri under the California Aqueduct. At this location, the channel is 56 feet across, which narrows to 30 feet across and is deeply incised, with steep banks on either side. It appears that the channel had recently been dredged at this end of the drainage, to remove excess sediment to improve flood.control. Due to the presence of cattails (Tvpha sp.) in the dredge spoils deposited at the top of the banks, is assumed this channel was dominated by cattca"is. Remnant wetland vegetation on either side of the channel include cattails and rushes (Jurcus sp.) located from the 011W to 3 feet up the bank- The steep banks were dominated by upland vegetation Lncludin� annual rye grass (Lolium mult�orum), wild oats (Avena fatua}, fiddlctieck (Amsinckia inen_>iesir), bromes (Bromus diandria•, Bronuts hordaccus), and California bur clover(Medicago polymorpha). As Patterson Run meanders across the site, the channel nwows to 15 to 25 feet, and becomes less incised. The channel is dominated by cattails, curly dock (Rumex.crispus), and rushes, vith an occasional willow (Salix sp.). The terrain becomes more flat, and the banks are dominated by creeping wild rye (Leymus triticoides)• Agricultural practices such as discing and oat cultivation are conducted up to the edge of the banks of the drainage on either side. At the northern end of the drainage, willows dominate the overstory, and the channel is dominated by creeping wild rye, rush (Juncus effusus), and cattails. Creeping wild rye, curly dock, prickly lettuce (Lachica serriola), rabbitsfoot grass (Polypogon monspeliensis), and Bermuda grass(Cynodon dactylon) grow along the sides of the channel. The top of the banks are characteristic transitional areas, with mixed upland and wetland vegetation such as pricldy lettuce, wild oats, western nettles (Urtica sp.), cocklebur (Xanthium strumarium), Italian alus), willowherb (Epilobium brachycarpum),' alkali mallow thistle (Carduus pycnoceph (Malvella leprosa),Jimsonweed (Datura stramonium), and rye grass. VAien this area of Patterson Run was delineated on November 21 1997, the.bottom of the : . channel had deep soil cracks and the top 6 inches of the soil profile.was_saturated; providing a positive indicator for wetland hydrology. -Vegetation showed evidence;of flowing water and sediment deposits. The soils were clay loam, with moderately abundant mottles Allof the wetland criteria were met,indicating that Patterson Run q ualified as a wetland.area -- -----