WPC  2BR Zp#|Arial ItalicArialArial BoldHP LaserJet 4 PlusIIHPLA4PLU.PRS2xCQ\'sZX2n X|TOO 9ND,C2xjAG;X1mC9,  Xm2PG;XP/qC:,cXq2pPG;X"4^DDV6OOYAOAADDAwDADn6wD66w6RwDwwwuR?ROAnOOODOOOOOOuOAwCCCCCCCCwwwwwwA6AAA6AAgww6A6[6RRRwwwwTDDwuuu6RwDwwDu414WddddddddddddddddddddddddddddddddddddddddNTT~PYVPTO33PPPPTTyuu3OuO"uu~uu"m+^99Ipp.DDNt9D99pppppppppp99tttp̅}9ep}}999\p.ppepp9pp..e.ppppDe9peeeeE5EtD9sZDDD9DDDDDDpD|9pppppȰepppp99999999pppppppppepp|pepppppeeee|pppppppppppp9.999.99Xeep.p:p.pDp.pxppppȼDDDeeee}L}9}9ppppppe}e}e}epp.pDe}9ee|pp8dp,(,WddddddddddddddddddddddddddddddddddddddddNHxxHlpD|pppppLJpDHpD,,DDpDDxppxHxxHsdd,DdD"dxdldtxxd"m+^:D`pp8DDLt8D88ppppppppppDDttt|Đ|8p|||D8Dtp8p|p|pD||88p8||||LpD|pppdL8LtD8ttDDD8DDDDDDpD|8pppppȰppppp88888888|||||||||pp|||p||ppppppppppp||||||||88888888ppp|8|L|8|`|8|||||ȼLLLpppp|`|D|D||||||p|d|d|d||8|Lp|Dpp||:dp,0,WddddddddddddddddddddddddddddddddddddddddNHxxHppD|pppppLHpDPpD88ddpDDxppxHxxHs||8ddD"dxxldtxxd2  P #Xp2PQ XP#e  yxdddy Jicarilla Lower Mundo|'`v(#5Conceptual Design   X.XCONCLUSIONS (# XIn the previous section of this report, the hydraulic and geotechnical modifications were evaluated based on their constructability and probable cost of construction. The estimate for each alternative was summarized in the previous section. The recommended final design will be chosen based on both constructability and cost.(#  R A.` ` Spillway Protection(#` XX` ` From a constructability perspective, either plain riprap or wire wrapped stone would be feasible. From a cost perspective, the type of spillway protection that would be most cost effective depends greatly on whether riprap would have to be hauled in from off the Reservation. The cost of hauling the riprap would probably make wire wrapped stone more cost effective. As it is likely the larger sized riprap would have to be hauled in from off the Reservation and because of the familiarity of New Mexico highway contractors with wire wrapped stone, wire wrapped stone is recommended for protection of the spillway floor and unprotected embankment.(#`  RD B.` ` Embankment Raisure(#` XX` ` There is little difference in constructability for the two different heights of raisure. However, raising the dam to Elev. 7336.5 requires the construction of an auxiliary spillway. The probable estimate of cost indicates the cost of raising the dam to Elev. 7338 to be approximately $400,000 less than the cost estimate of raising the dam to Elev. 7336.5 and providing an auxiliary spillway. Therefore, the recommended option is to raise the embankment to Elev. 7338 with a 2 foot parapet wall to increase freeboard.(#` (,))Ԍ R ԙC.` ` Seepage Control(#` XX` ` Foundation seepage and stabilization can be assured much more reliably with the remove and replace foundation modification option. The slurry cutoff wall options allow very little assurance of quality control and no review of actual interface conditions at the contact with the rock. The slurry cutoff wall options, however, are estimated to be much less expensive than the remove and replace option, over $600,000 less expensive. (#` XX` ` The probable estimate of cost for the upstream slurry cutoff and the slurry cutoff through the center of the existing dam are similar. There are some significant constructability issues with the upstream cutoff wall. The slurry cutoff through the center of the existing dam would have to be deeper than the upstream cutoff wall. Placing the cutoff through the center of the existing dam allows a level working surface from which construction sequencing can simplified, thus more adequately assuring closure when compared to the upstream cutoff which would have to be placed through sloping ground. Because of the improved assurance of constructability, the recommended seepage cutoff is to place the slurry cutoff through the center of the existing dam.(#`  R D.` ` Foundation Remediation(#` XX` ` Another issue is the potential for earthquakeinduced settlement (liquefaction) of the foundation materials. For each alternative the embankment will be raised with the material being added to the downstream slope. Consequently, the added weight on the downstream slope will act to stabilize the foundation materials against earthquakeinduced settlement. The remove and replace option would also eliminate the liquefaction potential for the foundation materials on the upstream side(,)) of the embankment. The slurry cutoff alternatives, Nos. 2,3,5 and 6 would will not improve the liquefiable materials on the upstream side of the embankment. (#` XX` ` If the loose soils are not modified, the liquefiable materials on the upstream side of the embankment will remain subject to settlement from a seismic event. This settlement, if large enough, could cause significant loss of freeboard. The calculated freeboard provided for each alternative is 3.5 feet above maximum water surface elevation. The liquefaction analysis calculations for boring E3 from the DVA and a 10% volumetric strain indicate the settlement would be approximately 3.6 inches. This would obviously not cause an overtopping of the dam to occur for maximum water surface conditions. Even if a PMF flood condition with wave runup and an earthquake occurred simultaneously there is little probability that the earthquakeinduced settlement could cause overtopping of the dam. The settlement could require some minor maintenance effort to restore the freeboard and repair the splash wall. The extra expenditure to modify the foundation by the remove and replace option does not seem warranted.(#` XX` ` The recommended improvements listed above correspond to Alternative 3 which is shown in drawings MX222 and MX226.(#`