TWENTY-ONE PLANNING FOR WATER-RESOURCES DEVELOPMENT. ie work associated with the design ofa project ofthe structures. themost important aspect engineering for the project. Because each water-development project's ‘ios desirable y the most desi change in einoogy.economie dv ae uae ied the plan must be weneing ‘evi Plans genraly mst be eevised pe a en ont watermanagerert plan, eloped organization ‘rater problems dies for prodocton of food, ener. indus goods. bo speci targets for water management me ‘most countries water development for specific purposes ity of several agencies. To provide sre cordiation ‘groups may exis natural "region(662 wares nisounces motseERING } LANSING FOR WATERSRESOURCES DEVELOMMINT 643 212 Phases of plansng Project planning osualy pases through several phases | ‘before the final plan emerges. In cach country there ts a specified sequence with | ‘specific nar ie e zt fase oF reconnaisance study is Usually a coarse sereen possible and the factors most For example in feasibility of an itigation project. Unless available data are clearly sufi evaluate water needs and soures, the hydrologic analysis may be the cont aspect of planning In other cases, the character of the soil, avail ‘oir ates, or even the adequacy of the foundation ata possible dam site may ‘govern. The allocation of effort in 1 process should be such as 10 leary answer those questions wt of other topics may be let to alate stage Selection of stall. programs of data those wtivities which deserve further study bbe one or move phases intended 0 the process to nn many cases is elatively i because the nature other eases one or more prefs taken to examine various aspects of the een the weakest aspects ofthe proj may be increased because many things ‘The easibity study usualy requires specified in sufcient. ofthe effort, the det igs and specications produced. Although, in principle ity was decided on the basis ofthe [esi the more thorough study may develop inf Consequently the decision to proceed shoul final design is complete | needed but considering a range specified by varying factors in the forecast he future and evaluating the forecast 1s clearly iesome provision of rig Teast es attractive ‘ear that other alternatives are not * US Water Reuss Come, asd esate, Pdr Raptr YOU 3 ‘ss(664 waren nesouners ENGINEERING | PLANNING FOR WATE-AISOURCES DEVELOPMENT 665 of these terms are “water needs” and “ water requirements” Generally, under present connotation, these terms should be translated as the “amount of water er than the “amount that will be used.” Often the imated on the basis of assumed * which are often also projections from presentse rates. The fole of cost or of technology in modifying the actual fature water use is rately considered. Estates | may be quite unrealistic and somewhat equivalent to saying that every family t needs” lead to overdesign and excessive costs he diversion of water from other uses which are ty. When excessive allowances are accepted as values of the real need, conservation of water is discouraged. Often bargain prices are adopted to encourage water use up to the capacity ofthe overdesigned works | Rational planning should attempt to estimate true economie demand rather than | 8 fictitious need. phase of planning where imagination and skill are required. The important fst sonsideration is the compilation of alist of alternatives. Such a lit should be en a preliminary project is in hand as the first phase of the jon, and the operation is reduced to attempting to justify this plan, is wrong, The planning process should with respect to project features an ith the assumption thata specified qu point X and to evaluate the merits price. A considerable amount of e nd, hence, pricing-p ‘Many terms are used qui and delivery of the water. Te planni © considerable feedback. As project formulation proceeds, t new data or projections are required or that some revision of| needed(66 waren nesounces nvcineenine lands for specifi purposes, Le, parks and sites for water storage (both surface and underground) can be defined ig capacities evaluated ing Fock of water use exist and must co 18 may reserve certain lands oF pre to be supplied ‘These restraints may simplify further steps by eliminating some alternatives fom consideration. No unnecessary constraint important to note that a varity ofalternaties ing alternates various locations or heights of should assure ble Th should be evaluated fe the optimum combination. M | PLANNING SOR WATER-RESOUNCES DEVELOPMENT 667 OS Fre 212 Neen ace for eit Fer pee. ‘anet-beneft surface (Fig. 21-2) (or multidimensional space) ‘maximum net benefits which determines fom the economic viewpoint the optimal mix of purposes. The same will be tru of projets combining a number of spare ble units Besause ofthe relatively large number of comb ‘many units and/or purposes aze involved sn dollars may be computed. With many units and various possible com- brnations of water uses at each unit, a large numberof tal is indicated. A digital ‘computer and some system of sampling are essential From the wotk reported by Hfschmidt. wt appears that a random-sampling procedure may be the most cffcient means of defining the general nature of the response surace. Once the Fegion ofthe peak is defined. second random sample ora niform grid sample the region may be used. The candom-sampling procedure seems most elective when the number of vanabes is large. ‘benefits or costs of water projets can be measured in money terms ‘The social costs of requiring people to move away from a feservowr site oF the peace of ming wth in deseripe has been common toYY appre ‘of recreational land provided, ralue of commercial fish. The ‘maker must then weight the economic and environmental factors subject ig be made by the public or individual planner, considerations in planning The decade of the 1960s will be 1 period of increasing concern about man's envi growth combined broad-gaged, and more critical of ms of “need.” They cannot look to quantitative measures of beau cology to develop their plans. They cannot rely solely on a show benefits such steps as dewsing ways ‘of the real need for a project. ‘a reasonable assumption that public works necesa ible assump pe sass health and safety and the accepted ameniti works. Hydrosletric projects may be considered a esse PLANNING FOR WATER-RESOURCES DEVELOPMENT 669 tin in humid regions, lod land management, storage to modily } | desig of struetures special thought appeara lecatment of faces to avoid large expanses of concrete, coloring to blend wi which have been iden meeMeER MEN PUEREETSRER AUUSTTUNTEVE SY FINESSE naereeets670 warn nesounces ncisERING Lanna Fem WATER RESOURCES DEVELOMMENT 67 The preliminary report Because ofthe large number of possible projects itis faily port ona project asthe first phase of project can be dropped without procedures In atu, he ty of by water use should Anything ess to expected Agency standards Standards of design and methodology may not always be ular ease ofa project. Technological advance may also dard, Strict adherenc andards should not be construction Assuring that the economy ‘esiment postponed for 10 ye at 65 percent inter traction ofa project substantially be in project planning A study of project reports bycost of the addi ed by us his type can lead to incorporation of uneconomic snerements i No stich decision should stand unbl its incremental benefit-cost PLANNING FOR WATERRESOURCES DEVELOPMENT 673 in a relatively short time. One obvious alternative is to Limit the development of such areas t0 can be accommodated within the available water sop- plies. A second alternative is to import water from some nearby region of surplus. For many reasons these alternatives may be undesirable, and efforts to find other ‘ways of augmenting water supplies are already under way. cevapotranspiration. Such plans Quire that they be approached wi fffort has been devoted to localized precipitation increases by cloud seeding. averaging about " 4€6 the mean annual runoff and precipitation respect 1s Based on the analysis of seven rural basins. It should be used only Py < 05. The study Was BF formed by using digital simulation to compare runoff from observed previ ‘Desalting of seawater (See. 15-15) sa feasible but t depends on plant size and th very lang nuckar power pants as a source of energy and heat, costs are within acceptable ranges for tirban water supply but far beyond reasonable costs f Tocations are in need of plants in the billion gallon per day (38 millon where the scale economies would become effective. Sine the674 ware RESOURCES ENGINEERING le consideration is now given to methods of meeting present needs with less water. Sewage disposal by water transport and dil conversion of brush and the environmental impacts should be closely studi ‘of water are made unfit for use by the addi mpervious areas 19 regulate and store. Wher Seating the soil 30 ‘yield in arid regions. Sin recovered, the yield PLANNING POR WATERSRESOURCES DEVELOPMENT 675, projects The previous sections of this chapter have dis- projects serving several purposes. Many hydraulic none ofthe bai purposes water supply. igation, food mit ich is designed for single purpose but which produces benefits for other purposes should not, however, be considered a jurpose project. On Hudson River basin New York (completed in 1931), which combines flood rit gation with storage of water for power and industrial use downstream. ie single-purpose viewpoint, Multiple-use planning. however, involves more than the simple cormbination of single-purpose ce “Therefore, this and the following sections discuss the special problems of muliple- purpose planning, None of the possible uses of a reservoir is entirely compatible ‘with any other use, although under many circumstances i some uses into good agreement. possible to bring ise. A working plan must for euch purpose although ingle purpose. The phys- sluiceways. gates, power pose project. The wnique maximum efficiency is not necessarily cal elements of a muliple-purpose pro} no storage is joi first instance storage requirements forall total storage requirement which ean be 9% al requirement> in maltiple-purpose projeets The success which can ¢ use of storage space in a multipurpose project 19 which the various purposes are compatible. Its depends upon the ext * Sympowsey on Multiple purpose Reserves, Trans ASCE, 19 98,180(616 waren RESOURCES ENGINEERING angio ease | ter sup ease gun rece helpful, therefore, to review the requirements ofthe various uses and to consider the ways in which these uses may be coordinated. Inigation We eens x tin ae aly sea Wi tmum dring the summer dry saton snd ie ~ ricmats do nat vary gealy om Yat oe Iowan yes usualy reste a pete gaton demand tha hgh ry constant. Since tigation soa able as much reserve year an provision most be made for this int @ reserve toavoad water shortage dung doug ecessary. Sanitary prcautins may prelude oso the ees fo erator purposes. has a mated sas vanaton ‘pending er plansare parts an mtrcon oped act em an consul eb spon TReee oe compatble iether sce Wate ested roma eer for i therfore move compatible with oer ek ome itugaon ise downatear may Be assed though crce sta In the exteme, power production maybe ited to those times whe PLANNING FOR WATER-RESOURCTS DEVELOPMENT 677 feleases are necessary for other uses oF to discharge excess water. However, this say result in alow load factor forthe plant, wth loss n overall eliconcy. Mec integrated power systems do not have need for many low-load-factor plants ‘Navigation Reservoirs designed to provide water to sustain downstream flows for navigation represent a ed Seasonal water requirement, with peak releases required duit ter portion of the dry season. Reservoirs for stack. water improvement of for navigation must be limited in height because of see cannot have large storage allocations for other the need for locks, purposes. ‘oad mitigation The basic requirement of food mitigation is sufcient empty Storage space (o permit withholding of floodwater during the flood season, rarely practicable to design a large reservoir for recreational ‘onal benefits are usually incidental to the other 1 project. The ideal ree reservoir is one which remains luring the recreation season boating. fishing, swimming, and Spore. A reservoir subject to large drawdowns is usually unsightly and crea ms of maintaining docks, boat moorings, beaches, and eth, Waterfront facilities in usable conditions, Fish and wildlife The problems of fish and wilde in large reservoirs ones of protection. Reservoir construction resus in amajor change ¢xisting wiklife and may result m a decrease in one sprees ant en Tequite the provision of fish ladders or '€ Migratory fish to travel upstream, rel are harmful to fish, particularly at awning period. Complete stoppage of flow below the sh and wildife Dams which flood spavining grounds Hus the fish runs. Unless suficient natural spawning ion of « hatchery may be necessary to maintain the fer ly © a Iso destru of migratory fish wi grounds are left, in 9 Low-flow auger ie dilution water s ispress tm the lower levels of the reservoir Mosquito control If desired. a ceseevoir can be ope fowth through rapid fluctuations of the water level shore. control mosquito ch strand larvae on the(678 waver nesouncts eNamNreRINa ‘of water which eannat be j these functions must providea clear al to each (Fig. 21-3), Since power development is not a consumptive use, any water released for the other purposes may be used for power, Ifthe operated as a base-load plant, its water requirements may ‘elatively uniform releases for other purposes. peaking. an afterbay or downstream reregulating dam can be provided to sm« tions of the power release. The alterbay storage capacity need be sufficient only to regulate flows fora ig dam may produce a smal ‘demand may not coincide wi ca often be used for power jn. The dam will usually be low and the controllable storage fairly small he plant may operate as a run-of-river plant. The modern tendency has ‘been toward higher navigation dams because of the need for fewer locks and the ‘improvement in power head. The area of such high pools may be sulicient to tion by the addition of a fow trade avalale when teqied by casing spllwy cet gues. Ary 886ton Space avaliable when feod ocr ued But tno ependable Theva the bench of sage for Rood miation, only tha ace of the naturachannelstoragein the each supe by ‘ ee can be made where a di se space which would have been nesled Teguhtion of Rood Tova. Fe can bs construct to show iat he reservoir may be safely fill (Fig any date and the dates dui PLANNING FOR WATER-RESDURCES DEVELOPMENT 679 Ofien some storage above spillway level is reserved for flood imes i serious floods can occur in every month ofthe year. A tule ‘in amount of storage to flood mitigation with the proviso floods are unt Purposes provided there is suficient ino I be filled eve fered as seco ‘There is no guarantee that this ‘and hence the water which might beheld there must 'y Water, ional beneiits of a reservoir are usually tke In some cases it may be po need ot be drawn down excess Picnic grounds, access roads, boating facil for reereatio i may be closed olf by a ined at a constant te a subimpoundment which ean be m level for swimming. Usually such subimpoundments are too s om ly Pot(680 wateR nEsOURCES ENGINEERING What has been production. The operat maintenance of adequ: eee Cee eee ee the storage below 1nd power head. Thus fish and wildlife aspects of me of this space might oecome a charge agai the project. BIBLIOGRAPHY Panning” Nat Tech PLANNING FOR WaTERORESOURCES pevRLOPMENT 681 SPECIAL BIBLIOGRAPHY: Systems Analysis in Water-Resource Planning nV T Chow (64) "Hand sof npt-Ouipet Relabone or eigation Wate, Austra J ist led Angotated Bibliography onthe Analysis of Wate Rsoures shal Analysis of Water Resouces Stems” MsGraw- Hill New Yor, 1m Design of 2 Mliple Purpose Reservar. J Hydro Dit, ASCE, Vo. 9. my 5: Optimum Legation Practice under Conditions of Defcent Water Supp Trans. Amer. Soe. Agri. Ears. VOL 4. pp. 79. 57-19, 1966 ted RW Shephard: “Optimum Operation for Planing of a Complex Water Resources Syste.” UCLA’ Engneeing Rep. 67-89, Univesity of Callomia Water Resources Cone, 196? Hiichmidt, M.M, and Myron Fierag: "Simulation Teshnigues for the Degn of WaterRescutce ‘Systens” Haraed, Cambridge, Mas, 1968 December, 1973, Loucks, DP: Computer Models for Reservar Regulation. J Saniory De. ASCE. Vol 94 Pp 659-669, 196 ‘ACComumeat on Optimization Methods for Branching Malt Stage Water Resources Systems. Resources Research Vol 4, p. 447-450. 1968 Managemen atonal Water and 3.4. Cole: Optimum Contol of Linked Resrvos, Water Resures Rescurch pp 419-498, 1968,