Laserfiche WebLink
<br />--~' <br /> <br />- <br /> <br />.... <br />-.1 <br />-.J <br /> <br />- - <br /> <br />- "...-- ~', <br /> <br />- -- - <br /> <br />- - - --- <br /> <br /> <br />U,S, Department of the Interior <br />Bureau of Reclamation <br /> <br />Salinity Updat <br /> <br />Las Vegas Wash Unn <br /> <br />Thunder sl'law~ dunng July and August <br />brought several waves of flOOdwater to Las <br />Vegas Wash whICh eroded a 4 toot deep <br />channel through :))XI feet of cattail marYI, <br />The channel cut through two road crossings <br />and tool<. out a USGS gage at PabCQ Road <br />The USGS prOVlslOflal estimate oj the Initial <br />peak dlSChargels8,6OJcubicfeet per second <br />lcts) lor a statiQrllocated 45 miles upstream <br />01 Paboo Road <br />Canalis were floated lree as the high water <br />lifted ltlelf root system trom the sludge <br />deposited over the past 30 years by sewage <br />treatment plant effluent. Several acres 01 <br />Hood plain were \eft stnpped 01 cattails. and <br />an open channel now extends 3.0Xl teet <br />upstream 01 the erOSion d1annel Only 700 <br />leet of canall marsh separates the open <br />Channel trom an upstream channel which <br />carnes the sewage treatment plan! effluent <br />This dally Ilow at about 100cfsIS expocted to <br />deepen the eros/Ofl channel and possibly <br />advance the headcut eros",n <br />As lt1e eroslC)(l Channel deepens. the <br />cross-sectional area 01 the saturated <br />allUVium diminiSheS Also seepage from the <br />channel would presumably be less than from <br />the marsh. The reductIon In seepage and <br />saturated allUVium may result In a reductIOn <br />In the amount 01 native salt leached by the <br />under flow through the stream allUVium. <br />Two years atter the 19a:J efOSlOl1 channel <br />advance of 4,50) teet the salt PICkup In thiS <br />lower reach ot the Wash began to drop In <br />1983, no salt pICk upcould bedetec1ed In thIS <br />reach, Reclamatl()(l hydrOlOgiSts Will be <br />moflltonng a oon\lnuous record at <br />conductiVity and discharge above and below <br />the erasion channellooetermlne It thiS year's <br />channel development also has a salinity <br />reductIOn Impact <br /> <br />Grand Valley Monnoring <br />The USDA Soil ConservatlC)(l ServICe <br />(SCSI as part of Its Colorado Rrver Basin <br />salinity control program has begun an <br />on/arm ImgatlOn monrtonng program In lhe <br />Grand Valley Sites have been selected <br />across the valley to represent many of the <br />sods and crops common to tl1earea WItl1 the <br />landOwners' cooperaboo. monltonng <br />eqUipment has already been lnstalled 0f'1 <br />severa! Sites <br /> <br />rterfy Report on the <br />River Water Quality <br />rovemenl Program <br /> <br />Octob~H 1984 <br /> <br />... ..:"" <br /> <br />.. <br /> <br />- A~~ ~~.it4 <br />~ - <br /> <br /> <br />1: <br />L.. V~9" W..h uptHearn 01 Pabeo Road. <br /> <br /> <br />Channel, in center 01 photograph and barren area In lower rIght were e_potecl by th~ departure <br />01 call1U. during July 11000.. <br />