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'. ('IJ (.') C'J t'1 . Features of Plan -----_.- The princ~pal features would consist of a channel heading structure, located at a point about J miles northeast of Artes1a, a low- flow conveyance channel, a flo~dway levee, and a cleared fl00dway extending from the heacU~g southward th:,ough the ~elt!; into Mc!1i:;'lan Reoervoir, a distance of ~:)l'le 16 miles. The capacity Qf the channel would be 1~500 cubic feet per second; that of the floodway 40,000 cubic feet per second. The heac5ng atc"1.1c,<;U:'s would bs of conc~ete and contain 4 corrugated metal. pi;o9 o"tle'~s equipped with sC:':'ElW lift control gates. The conve;~~ce ch~~nel would be lccated approxiraate:;'y 2,100 feot f~om the east ed"e of" tile delta G.r-ea fOllc,jing roughly the uelta boundary,. The channel sh';Js ,,-ould be trapezoidal, with a Llinir",.un bottom width or 21;.,5 reet, a cor:'-",p:mding wat.er dep~h of 7.9 feet, sids slopes of J tQ 1, and a minimum L"eboard of 2 f'Jet., The hydrauliG properties of t~e channel vary in accordance with g:..'sd:.,o[:'s, the raqu;.remants for a stable channel in alluvium, and the :requL:ci""""';s for pj..ac:tical and econom- ica!. l'~:1stnwtion, A 50-foot berm along t",,; ""-dt 8i~e d the channel would cC'ntain a graveled maintenanee road, TI1" :loC'c1way levee would be construc- ted at ~he east edge of the ~erm. The f1ood~.ray would e:>r~end from the levee tC' the generally high ground at the east side of the delta alBa. A 2;OOO_foot width would be cleared of salt oedars, 19aving a 100-foot strip along the toe of the le'rae for protection against s,:our', The levee would range in height from a minimum of about 6 f€let "\:.0 a maxiIlllllD of abou'G 12 feet and would permit the passage of 40,000 cubio feet per second through the floC'd- loI8y with a mj.uimwn fl'EleboaX'd of thl€e feet. The top width of the levee would be 15 feet and the side slopes 3 to 1. Below the point of inter- section with the normal water surfaoe of the reservoir, the height of the levee would be deGreasod to the height required to Garry 1,500 cubic feet per second in the conveyance channel. Low flows would be diverted from the flood way into the channel by a temporary earthen dike across the floQdway entrance. Normally) all river flows up to 1,500 nubicfeet per second will be carried in the conveyance channel. During periods of higher river flows~ the amO'.mt admitted to the channel may be regulated by the gated heading structure and the remaining flow diverted into the flood- way. ',Jhen diversion into the floC'dway occurs, the temporary dike at the head of the flood\lay will be overtopped and brea~hed. Upon recession of the flows, the temporary dike will be reconstructed. The irrigation releases froLl Alamogordo Reservoir will be c00rdinated with river flowe at Artesia in order to minimize the occasions upon which combined river flowe and reservoir releases exceed conveyance channel capacity. 4