it it it it

estimated that the total water use by phreatophytes in the 17 western states amounts to between 20 and 25 million acre-feet per year.

Better control of plant growth likewise offers an opportunity, as yet almost unexp ored, for salvaging water. For example, a recent editorial in Engineering Ne "s~-Record indicates that the Forest Service considers that harvesting d periodic thinning of young forest rees could produce a permanent increase in watB~ ri31d of 25 percent.

Because the precipi ation is erratic, storage is an essential instrument in making water available for bellef-Lcial use. Dams ard thrown across stream~ in order to store water until it is needed. Lakes and ponds serve a similar purpose. The soil acts as a great sponge to store water until it is called upon by the plants or un-Gil it is pulled down by gravity to the water table. And the ground-water bodies likewise serve as giant reservoirs that receive water from the soil and slowly pay it back to the stream system, thus providing the dry weather flo",. The ground-water reservoirs dwarf the mana-made reservoirs, containing many times as much wate~ and they do not lose water by evaporation. Therefore, a substantial amount of water would be salvaged by reducing evaporation losses if water from surface reservoirs is artificially introduced into ground-water reservoirs. This practice is being followed advantageously in the Los Angeles Basin; at Des Moines, Iowa; Valley City, North Da.kota; at about 150 municipal-supply plants in Sweden; and in Germany·, and elsewhere. In west Texas, where the underground injection of surface water is being tried, the enabling act which created the water district provides

that the money collected as water-use taxes shall be spent only on research and education problems in water recharge. Artificial recharge would not be possible except under favorable conditions. However, according to Conkling, tlNo matter how large the surface reservoir capacity, it will yield fo useful purposes no more than 50 to 60 p.," ,-cent of the average annual discharge because the remainoer will be lost byevaporation." Thus, artificial recharge as a means (i. salvaging

water is worthy of considerable study.

Many of the western streams receive inflow frGlli one or mo~e springs of highly charged brines. Clifton Springs feed 60 tons of salt daily into a tributary of the Gila River and only four acre-feet of water. Brine springs of similar character pollute the Pecos and many other western streams. If feasible mean~ of preventing these brines from reaching the river could be found, a substantial increase in irrigation would be possible.

I have briefly described a few of the more important ground-water problems of the West and have attempted to point out some of the ways in which water can be conserved and made available f0r beneficial use. The feasibility of the reuse of water by industry and the useful-ness of artificial recharge have already been demonstrated, as has also the saving that results from careful application of water to irrigated land. ()thers o·~' the suggestions have not been demonstrated as yet. Some of them doubtless are impractical for one reason or another. However, there is considerable reason for hoping that sub-stantial progress can be made in more efficient use of water, because

the understanding of the hydrology of our water resources shown radical improvement. The deficiencies in basic data hich have been recog-nized by every group that has considered the national water problems are slowly being corrected with full suppo ,t of the people of the whole Nation. I think we can confide. tly 1 ok forward to the day when the optimum use will be made of aU.'L" '{Jater resources0

Address by E. O. Larson, Regional Director, Region 4,

Bureau of Reclamation, at the Annual Meeting of the National Reclamation Associa.tion in Reno, Nevada,

October

14

to

16,

1953

I always say that I am a charter member of the Nationa.l Reclamation Association because I attended the conference at which the idea for the Association was born. That conference, the Western states Recla.n:a.tion Conference, 'WaS held at Salt lake City, Utah, on June

26,

1930, for the purpose, as stated in a newspaper report, of "ra.11ying militant forces in the West in defense of reclamation as a part of the policy of the Federal Government." Three resolutions were adopted.

Resolution No.1.

"RESOLVED: (1) that Federal reclamation has been and is of great benefit to the entire nationj (2) that its continuance is essen-tial to the future growth and prosperity of the West and of the nation as a whole."

Resolution No.2.

"Realizing that the highest beneficial use of the limited water resources is essential to the development of the arid and semi-arid areas, it is recommended that whatever agency is used in the development of the irrigated lands shall operate under the respec-tive State laws exclusively in the appropria.tion and the use of water.rt

Resolution No.3.

IlBESOLVED: That this reclamation conference recommend to the Western States Conference of governors (held the following two days) that they appoint a committee on reclamation to report annual.I.y to t1.:.e \o!e~tern States Governorsf Conference and to

func-tion ~r.CJ. matti~~':8 I-ec'caini:ag to reclamation during the interim bet'Wbcn meet':'llgs.H

When this first conference was held I was an employee of the Bureau of Reclamation engaged primarily in project planning. I am still an employee of that Bureau and am still devoting a large part of my time to

project planning. I am pa.rt~c'U1a!'ly 1m.~as~i 'With" the second -resolution whieh I have just quoted. After nearly"e,'quarter of a century durin@' which we have made vast progress in developing our water resources, this questicD of State 'Water laws and their application to the Federal Govern-ment has not been resolved. ¥.any of the same points which were raised in the early thirties are atill a matter of real concern to all of us

involved in this work. For this reason I will devote some time to this subjec t in my talk today, which is entitled "Planning 'Water use projeots under Federal and state laws." I should add, at this .point, that I am purposely repeating tr'."llvh of lThat I said at the annual convention of the

We8~ernstate Engineers i!l August. I do this for two reasons - I 'WaS requested to do so by your execut1ve c ommittee, and furthermore, I am convinced that the points covered not only bear repetition but need re:petition.

The position of the Federal Govermnent as a planner and builder of reclamation projects is frequently misunderstood. Such projects directly benefit a group of landowners and other water users of the project, and indirectly benefit the conrrn.unities within the project area, the State, and the nation. There is no conflict in the interests of the Federal and State Governments in developing our most valuable asset, our water

re-•

sources, and there should be no conflict in the method of attaining our common end.

My subject is broad but I shall confine my remarks to' the discussion of what I consider four of the moat ~ortant problems encountered in project planning. These problema have reached such proportions that they :Present serious obstacles to sound development. They are (1) uncertainty

as to the method. of providing water rights for Federal reclam8:t1o~ projects, (2) the padding and pyramiding of 'Wa:~er .rigb:~e, (3) ·the _~1eed for substantial amendments to State water lawe to )te~t·the requirements of_..large m~tiple-purpoBeprojeets, and (4) the lack of full state coop-eration with the Federal Government in project pl.a.nning.

These obstacles will be discussed in the order stated. Uncertainty of Water Rights

Over the past 100 years State water laws have been developing f'irBt~

by local customs and practices,; second, by Court decisions; and third, by

enactment of cott1prehensive water codes. The state water codes are ordi-narily divided into at least four ;parts: (a) general principles of the 'Water law; (b) appropriation of 'Water; (c) distribution Qf water, and (d) the (adjudication of water rights. There is no counterpart' of the great bulk

of

this basic water law to be found in the Federal statutes. The Western States

are

proud of their water codes and jealously guaifd what they term States rights to .the use of vater. President Theodore Roosevelt recognized state laws and vested rights when he urged the

enactment of the National Reclamation Act in hie first message to Congress December 1" 1901. He said:

" .. • . •• These irrigation works should be buil't ...:f 'the Government

fer actual settlers, and the cost of eonatruct1on should,' eo far ae possible, be repaid by the land rec.laimed. The distribution of' the water, the divisions of the ...at:fe~e among irrigators, should be left to the settlers themselves, 1n conformity with the state laws, and without interferenoe with those laws or with vested rights. The policy of the National 'GoVernment should ·:be to aid irrigation in th~ several States and Territories in such a·manner as will enable the' people in the local communities to belp the1X1- ('r, , selves) and as Will stimulate needed reforms in the State laws and" .regulations governing irrigation.It

In the hearings on the original Reclama.tion Act fear was expressed by the states that 'if the 'Federal Government e-ngaged in water re,source development it vToo.ld result in ,an encroachment upon the rights of ,the

.

.

States to control the appropriation, die~ributionand use of, Water. To allay these fears Section 8 was included. It provides:

"That nothing in this act shall be construed aa aft'ec:ting or intended'to affect or to in any way interfere with" ~e Jaws of any S~te or Territory relating to the control, appropriation, use or distribution of water used in irrigation, or' any vested right acquired thereunder and the Secretary of the Interior1

in c~rrying out the provisions of thia act, shall proceed in

COnformity with such lav..-s, and nothing herein shall in any ,\-my

affect any right of any State or of the Fadere.l Government or, of"' any' landowner, appropriator, or user of "W3ter in, to, or from

any interstate stream or the waters thereof: Provided, That the rj,gl;\t to use, of water acquil;'ed under the provisions of this Bct shall be appurtenant to the' land irriga.ted and bene fi'cie.l use s.hall be" thee- basis, the measl,U'E;, and ~he lim!t of the right. (32 Stat. 390).

, .

The Bureau of Rec1aJ:nation has complied with Section 8. It has ,filed applications Under State law for appropriation of wter for irrigation uses and in mQ.St cases for other uses as well.

During

too

last several years instanc-ee ha.ve arisen, here in the West which have called into question the procedures to be folloW'ed by the

Federal Government as an appropriator of water. Some.ha~ taken the poe1.. tion that the Gove!'DIOOnt is the same as any other a.ppropriator; while , others ccntend that the Government need not' comply with the State

water

Codea. The importance of this serious difference of opinion cannot be over-emphasized. The United States bas spent hundreds f'f millions of dollars in the construction of dama, canals, and other reclamation works in reliance upon water rights) ~oat of which ~re in the process of being-:perfected under State law. Addit10nal rights will be requireQ in the

future. Project, planhers must know how to initiate and. :perfect.we.ter rlghts for Federal projects., This problem must be solved 'Without further delay.

Paddine-a~m!mfdi~g of vlater~~

I now hlI'n to the second point mentioned at the beginning of my talk, relating to the effect on reclama.tion planning of' the common prac-tice .of ffpadding" and "pyramiding" water rights acquired under State law. By "padding" I mean cr~t1ng records of rights to the use of ~ter in excess of that actually ~neficiallyused. By "pyramiding" I mean filing and maintaining in good standing more applications for appropriation of

''Water than are required for 8 given purpose. It is my firm opinion,

baaed upon more than 30 years of experience in reclamation work, toot 'this practice is one of the most serious problems we are encountering. . in

dave'loping western water resources. The seriousness increases as the ~ter available for appropriation diminishes.

In planniug a project, the water Bupply is, of course, of first ,importance. Is the l..re.ter available for the ,intended use at the point of

diversion? Answering this question requires two decisions: first, whether

the water is physically present, and second, whether there is enough wate~

over and above existing water rights to satisfy the project needs. You oheerve that I mention .E~er ri8~~ and not ~;l'8,tez: ~.. This distinction mst be kept in mind. The first decision is baeed "J.pon engine,ering

studiee of water ciupply which will not be discussed here. The second decision presents problema of application and adm:tniatratian of State wter law.

I ' .

It will be recalled· that one of the :principal reasons for enactment by the various western States of their comprehensive 'Water codes_. 'WaE' '~o

. .~

prevent the abuses incident to adjudication

by'

the· courts of mox:e 'rfghta to the use of water than there was water

in

the stream. In: moot States, the legislatures placed the administrative control of appropriation of !Water in the hands of professional e.ngineers equipped by training .and experience to determine whethe!' a given 'Water 8'U.pply is exceeded and when appropriations of water should cease. The task ~f formulating proposed decrees in statutory adjudication suits has, in several States, ,been given to the state eng:;..Joer. In the case of Wyoming, the Board of Control

hanc.lea statuto::cy ac.judic~,tions,) ::n theory, tbe State procedure is gener-: ally sound, lbut in practice, I have found that project planners are still faced ,dth the same obBtacle, ne.mely, the "padding" and "pyramiding" of water rights. This practioe haa, in many areas, resulted in the adjudica-tion of 1Veter rj.g,ate in (~xcesa of the a-vailable, water supplj', although the actual use of \;ator Day fall far short of the" supply. I', shall refer to concrete examples with which I am familiar.

The first excl..npl~8 are frvIn the State of Co::'orado ~;here water rights are placed on record by the entry by the district courts of conditional decrees and'later by the entry of absolute decrees, when the works are constructed and the we. ter is put to beneficial uce. There has been a tendency in practice to cle.i:t; ()~ces3ive rights a~.Ld if not. contested the courts have frequently granted. decrees for the amounts claimed.

On the recently authorized Collbran proje-ct aQsolute decreed rights for- nine ditches aggrege:te 61 second-feet, wh1,J.e the total maximum. diver-'aions total

oJ,

'7second-feet. Decreed storage rights for existing reservoirs

total 7,800 acre-feet, and the etora.~e ea:pae1ty .~Et 4';900 acre-feet. Absolute decreed rights in,the Colorado Cooperative Canal,~~the,Sa~

:"1

Miguel project total 145 second-feet, and the cal'acity of the canal is 90 second.. feet. Some 14 ditches on the IaPlata project have r~ts of record totaling l20.aecond-feet. The actuai use is

6

eecond-fe~t~

In Wyo~ing, ~re.ter rights are acquired through the applicati,on method, and this is fo11o,:,:ed. by the 8,!\~iJ.dJ.c.~~~ionof rights by the State Board of Control. The 19~'5 leginlatu!'e g;re,n'~~da bonus water right to all holders of existing rightsII It passed a 1&,-1'; dec Jar-ing that "a right to the use

of aurpl....1.B "J!ate'!' ~a :1.~,:r,:-~-in d'1~~~J:leo. in thG emount of one (1) cubic foot of 'Water];lel' 0000:-.:.0. for E:8.Gh 70 ac'~ec of lo.r-1 havinG an ac.judicated 'Water

'r1gh~ or a water right under permit 12 hereby adjudicated to attach to all origi::J.al di-:roet flo~.; water ri~:1ts.II The statute :;>rovidea that the prio:.-ity of each cur~J.·~w wat.~l; riS::.;.t shall be March 1, 1945. This

etat-ute has the effoct of d')'ubli~.lg the rights on the l:"eco":ec.s.

Wate.r ri~:t8 on Bl:.cke F·.)~"k and S:.:d.tll Fork for' 8:2,000 acres of land. in the potentia] Lyman project area have been adjudi0~~ed. Water is actually urJed 't1:po~ onl:; 40,OJO acr~8. t The me&:J. streax::'f'loW' actually

feet. Adjudicate,o. rights total 1,200 second-feet and '\-lith the surplu6 water right gl'a,ntF)d by statute any project water rigl:.t woulcl be sub,j~ct to prior ri£':lte ag.::.:~:'(~gattng

2,hoo

second-feet. Ths project re!:lcrt cO:"J,c.ludes that prac'Gically no wa'cor wc'J.ld be available for d.eve] Gpment of t~:e 'Lyman project as pla.nned ·.:Liter satisfaction of exiet:lng rights;. 9.1thoug.'I:1 actual benefiCial use 1s bei;lg macle cf only slightly more than 'J~~ba1f of the 141,000 acre-feet of annual yield.

In

utah

tha

~pplication system is

uaed

~th watet right adjudiCaw

tibns handled by the court~ :aetween 1920 e.nd 1940, State agencies,,)

]federa.l agencies, private corporations a.nd water e:Pecu,la:tora f'ile0. g~o.ro~

..

of large applications upon all of the principal streame in the State

On the Weber River, for example, applications for storage of .more than '. 700,000 acre-feet of water we;re filed. Storage ,;reservoirs were con-; structed' with a total capa.cit~ of something over 225,000 aqre-feet., The pyramid of' ,other filings in good standing aggregating approximately

475,000 acre-feet must be disposed of before a water right can be ,assured for future deve'1:Jpment.

. .

I have me!j,t:Lcned specific cases of :P6,c~ding and pyramiding water rights in·Colorado, Utah and Wyoming",.not because the problem is peculiar to these States, bu:t because ltuch of my p].a.nning work bas been done there. Hawver, it has been reported that the abuses are comncn in other "Western States. We have encou:.1tered them in virtually every :projeot we have under

study in the pa~ts of seven of the States comprising Region

4

of the Bureau of Reclamation.

1._ f

These,padded and pyramiced rights frequently cover so much water that at face value 'tney exhaust the annue.ltlsupply of the stream, leaving no water for new developments. Even if a remnant supply of unappropriated water remains after alloTt18nce is made for these "paper rights," ita

devel-opment would"be con8ic1~rablymore ccnplicated and expe:nsive t:r,.an the

development of the more acce8s~ble and plentiful supply that is covered b;Y:

the JlpB.per rights.r1

I doubt

too.."

the, BU2"eau of Reclamation ,;will recommend proeiect,6, for authorization or t1J.a:tt Congress will appropriate money for construction

unless an adequate project· water supply"is assured. Not~ Only must 'Water be available for d.evelopment but it must be the first water remaining in the stream after bo:na'fide prior r~ghts are t~ken into account. It is unthinkable that the Federal Government or anyone else 'should be required to stand th~ expense of building costly reservoirs to store remnant watex-supplies ·tor new projects in order to :Perpetuate waste

of

more valuable water resources under. paper water rights.

Let me make clear that I do not question the right of an appropriator of water to a reasona:t>le time to build his works and apply the water to beneficial use. Those who comply with the law in good fa1j;h and by the

exercise of diligence in these things poee no great problem to Feder~l

project planners in appraising the water Bupply availa'ti'le for new develop-ment.

The Bureau of Reclamation, ae before indicated, appropriates. water for irrigation and related uses pursuant to sta.te laws. It hae, with few exceptions, no preferential rights and should want none. It f'aJ.l1lot in good conscience, however) recommend the construction {j! ~rojecta on ~ter

sour~ee where the full annual supply is covered 'by padded OJ pyramided

water rights or where excessive upaper rightsTl _{would unjustly increase}

the: ~ost.

~e National tntereet demands removal of these man·made obstacles .to 'Water resource development. It is a problem which'must be recognized

by State administrators and solved by bet-ter adminis tre'tfve practices and

tne enactment of curative le,giela.tion.,

I now turn to my .third point.

Amendments to state Water 1a.w

About 20 yea.rs ago, I was working on a multiple-pur:pose project involving irrip,a tion, !lmn1~ips.land. power use

ot

water, \Then

:t.

t became evident to me tha.t the etatc vmter laW' with rest>ect tb a:ppropriation df water.7 and :partj.cuJ.e.~.>]y that :dart of the Jaw relating to prbof ef app;ro-priation, d:f.d nct fit ~~l.G:1. 1::~ojecte. I realized. that the ll:!:w WS vt'itten many years ago to me;:,t ".;111:3 J~·e"'"s.tively simple r€)g.ui~1JI~:':r:'3 of 6rdinar.y

irrigation projcct;s or projects :('or municipal or mini:.le; use. Multip~,",

purpose projects were no~ known in the early days w:ten t.he fra.Inevo;;k of ou:' water law ....!a8 "Tr~,tt~n n~.:,d. 1-tere not within t:~e cor.-:.(~r::plE:ticnof the

Iegis:.ators. ':'he lav, as Q--:-afted) was not flf)~:j_~Jle C'J0"l..t)"1. for projects re~uiringwater from several drainage areas to serve tWG or more U3ee~ with the use c:!:langine.; 8.3 land ~a subdivided and Con"T9rtod from farms

to

res:! dontial ar8as. It did ~.~·it permit the appropri.3.tj.a'~)9~>b01d.-over _sto~­ age w.tar, a necGssity :t'or nn~:1Y projects today. Such -)roject.~ beoome mo~ce corrmon -as the availo.ble ','Water supply is put to use. In gen3ml, wbi~e the 'Western States have done a good job, amendments lu,ve not kept up with the changes, and the present law in moat states is not in all respects adequate.

The courts in two states have req.ognized hold-over storage as a. beneficial use

ot

water, but, so fax as 1. kno,,,) there has ,been no legis-lation on the subject. Such J.egiflls.tion shou:_G. ~)e r:i7en ca::."eful study,.

as it is obvious that a statute should not 'be too 1i'08::'8.1 or too reatrictive~

We have several projects of the t;r.pe of the Provo River proj~ct in utah, :and'the New4nQ.9 ...:project in Ne:v.ada, which requi.::oe water frQJIl two

or more draiJ:lage basins. S1:ould State la.w (1) permit appropriation of the

totel project supply, say, for example, 150,000 acre-feet from each source, with So provision that not more than 150,000 acre-feet of water shall be taken from all souroes combined, or (2) should en effort be

made to prorate the 150,000 acre-feet among the various sources of supply? If solution No. 1 is followed, it would unnecessarily cloud subsequent water rights and possibly prevent further development on the streams involved. If solution No. 2 is adopted, and a mistake is made in the difficult task of determining the quantity of water to come from each source, it may create severe '\vater shortages on the project in event of a low water yield on one or more of the sources. The answer must be between the two extremes.

Another problem commonly encountered on multiple-purpose :projects is that of following and reusing water brought in from a foreign water-shed. That the Federal Government can claim such return f.loW' 'Water has been established by the Supreme Court of the United States. The prin-cip1e ia clear, but without proper administrative control the right is only an abstract right with little or no practical 'Worth.

In States where water 1s appropriated under the application system,

. . ..

the making of :proof of beneficial use is virtually impossible on multiple-purpose projects especially if hold-qyer storage ia required and if the 'Water 'USe changes. as the years go by from irrigation to municipal and

industrial use. Most States are rather liberal

in

granting extensions of time for making proof (in U~h they can be granted for

50

years) but some-time proof. must be made.. We should settle the problem now and not :Pass it on to future generations.

The final point which I desire to stress is: Need for more State

The need for coore:t'e.tion a:nong the"~,tates and the Federal Gove1;'~nt

in 601v-:tng; epecific problems is impJ.ied in,each of the three points I have covered. I cannot emphasize too strongly:~the importance of ,more a.ctive pa.rtlci:pe.tj.on by the states apd lOGal:, coi$n'!.mit1es not only' in t.':1e broader problems of the water L.4w and ita adI'linf6tre:tton but in ell other phases of prO'jec't plan.ning, 'starting with the inj.tial investigations.

In recognition of the fact that Fede:~'al reclamation projects er~

far tbe prir:.al"y ·bene:!"':l.t of local intereats, the :B'lood CO:.ltrol Act of

1944 set up a pa~tern for conu1.l1tation ancl. cooperatj.on between ths Fede,ral Government and the affected states in prQ,~E"t investigations and plan formulatfonc. Th~ Act aIse pr.ovides fbi" the States to review and comment on projectl'repoTte. I am sure that the fu.l1 cooperation intended to result ''from the ect i.e fJ.ot being reati~d", This may

be

due in part to

; 1

the ah'o:::-tcominga of FGdc~ml agencies" but also in largor IWa,3u;e thooe

ot

Stat~~and local groups.

A:s Bodh as ·tJ."1e pro,,18ct plan bec5.ns to take shape·from

,reoonnaia-aancel'.otud:ieG' ~:~ is vitally ''i1nport'B:lt that, the, attitud.e of t~ people in

,~~:

the affected area be made knovrn.. The St,at~1 'itself haa a re8~onsiidil~i, in my thinking, to aasiet in. ti:faeenting the.?::plal~.i,to local-groups ~~ :i,.n

i(. ~ .. -. . . . ':'... ; '" ~

reeoncil1ng vm.eJ:;,e possible, "'ChEf' con.flicting,;yie'l'Ns of the val~~:Otl& ae~nt8

0'1'

~ople.

The official attitllde of th3

0~t~te.

:itself 6hOufii'rbe';4tpresscd.

~;

In .aU inatS,nces 't'There' the Bureau of Recul~tionis inVblved I would. JJr.ke to ~~~ it prima::,"ily in the role of an in7est~~ator an(i:~p~nfl~;J; '6?:'p~ojects

with the.;)chief responsibility for ~ponsel'ahip'ia:tJd:;.prCGloti&"T.'e·Bti~ with State ~ local int~reBtso

I firmly believe that Federal agencies should not undertake to

solve for local people problems that they can better solve for themselves. Many such problems occur in planning reclamation projects. As new devel-opreents are proposed in areas where considerable progress has already been made, complications are presented by established rights and usages and by existing structures. Adjustments and exchanges have to be negotiated. My ovm experience is that the best results are obtained when the negotiat-ing is done largely by local people under state leadership and with factual data and technical advice supplied by the Federal agencies involved.

It has been my purpose to direct your attention to four obstacles which confront project planning. I am not attempting to place the blame on water administrators, oourts, lawyers, Federal or state agencies, or upon any group_ The serious conditions I have discussed have just gro,\;m. up over the years. We should recognize they exist and action should be taken to remedy them. Curative legislation should be formulated where necessary, and I believe this Association can be of great assistance in encouraging and drafting such legislation.

In conclusion, I point out that planning of Reclamation projects in your states 1s vital to the -welfare of the Nation and of the States and local interests. It is essentia.l that all cooperate to the fullest to the end that this planning will be sound and wise.

Administratively, we are in the process of reorganization and str8amlining for the more effectivo use of the Reclamation dollar. In past months, Roclamation persormel ha.s been rDduced more than 10 p,Jrcent in order to bring ths number moro in lin:..: 1d.tl1 tile present program. A survey team has just co~pl8tcdan oxamination of the Bureau of Reclamation administrativ8 and 0pDrati.ng structure. Their recomrnendations are now bBfora thv 5Lcrotar:>r and we expect to have an announcement of furtJ-_'.Jr r0organization ~ithin·a short tim00

At the same time, let m8 say that I have a wholesome admiration for the career service within the BUrf.,au of Fwclamation. I b(;)lievc our tcclU'-lical people: havE;; few peers in their re~:;pective fiul(~s ~ I have the same confj.do:1ce in thorn that I am sure your experiences in the fi(~ld and on tho operating projects have given you~

In the admini strative changes which come vri th .:lny change in managemu.t, I have loob:;d first to qucl.lifiod BurGau of Reclamation career personnel. I believe we have a team. that will put Roclamation on tha upgrade for the big job th2t lies ahGa~.

Fo"r, what is the future of ReclE'.lTIation? Let me say th2.t before I took this ,job, I had conversations "'f;itt t"oth President Eisenho'wer and Secretary FcKay. I can.eav~ay from them oonvinced that they are as inter-ested as you and I are in moiting ahead Yv'ith the development of our '1lfater resources.

But we are all firmly convinced that there should be a greater degree of local participatton in all phases of the reclamation program.

This can be accomplished in a number of ways. In the early stages of planningJ we don't 1iJant you looking over our shoulder; we want

you right dmvn there beside us, Ymrking out the needs of your area and how they ce.n rest be fulfilled, Then "Ke l\rant you to figure out hov; much of the proposed v:ork yO"'.l [lre· able to do c:'.nd should do yourselves.

Some-times ;rou may find }OU are able to do the whole job. Don't think you .... "11 . hurt our f8elings by moving in and te,king it over. ':le have plenty to do

and need all the help we can gete

But ·when there is a project in YThich you feel the Federal Govern-ment should p[~rticj.pate, then you will ho.ve the responsibility of going to the Congress and obtaining an authorization and the necessary ~ppropriations to get the job done. You, who are aware of the need Rnd of-benefits which can be derived from reclnTr..:'3.tion development j_n your area, must come Clrmed iyith facts and fit~ures to subs-t:-1.ntiD.te your case •.

~;!e "Frill be glad to assi st, of' cO~J.l"se, b11t the major

responsi-bilitjT--the initi:::tive--is yours, for yol.l 2.1"e the people v;ho kno"v"~ best vlha t you 1"!~~nt and ~.:,rhy JrO,.l 7~ant it. Rather than htve the Bure~u ?.ct cl_.8 c2lesm~n

we ask you to be the s~18smen--bothlocally Rnd in Congress.

It is important to bec~r in nind, in t<:llkiJlg about grc-:later local pE·.rticipe.tion in the developmont oi' the recl:·.ffiA.tion progr:'lm, th::Lt there is ,~n accomptinyj.ng gr~atl::r degree of responsj_bili ty.·. As I havE; mt.:mtioned, tho keystone of r::. succlsssful recl!..matioT~ prOe~r....,.l-r: is the n.bili ty to demonstrate

to the Conerass :;.nd the H,:,·,tion th:3,t it i cf'rrying its OVIn weight and will repay to the Fedt:,r'll Governmt;,nt thG money invested in it,.

This !!l6t1nS th2.t w:) must ha,vo ensrgl:tic, cooporr1.tivG Clnd responsi..

bIE:. wP,ter USr)rs organizations ·vVi.th whom Yft'j c;:-.n d8Ftl in 1:orking out r~paymont ~ontr~cts and op(;ra tionr-.!.] .d.et,:,.ilsIt ~lfD l12.ve a 1;olicy of st·1.rting no

distri-bution systf,;m construction untiJ. (.;.. repayment contrr:ct is in hand.. y(;;t , it is wD.st&£'ul, r.ftcr t multi-purpose storage f?cility 112.8 been completGd, to

cJelay irri«\tion sl:;rvice. _{Wo urg':;; C),11 irrig:-.tion dist.ricts ano water users} org:-·ni~~.tionGwhtch nil.vc suer contr,s'cte pending to expedite negotiations in order that our rc,cl;:m;,).tion facilities mn.y be put to maxir:um uS"..- ~s soon as possib1.s.

fl.l10thor phase in 1Nhich therE, phould be gre·~.ter local pa1'ticipP:.tion is in tho r;tr-t.ttl::r of v:.3.tur rights. AS ,rou know, the j3u1'0....·.u of Rscl.. nation

h~LS r";.r,6. a long-st,~nding policy of abiding by Stf'.tu water lavrs and the

rights thoy protect i~l the administrCltion of recl:JIlla tioD projects.

N,::vcrtheless, '-He' nOVl find oilrst.;~.v8S, in some -:;1'0'18, in the posi-tion of litie,C'.nts in wc-.ter.righT,s C:;tS';"S under State lawlI We feel this

should b~' :J. 1'csponsibilitJ-" of the Stntt~ nnd the local wc-1.ter usors org2,niza-tions :md tr.Rt thE; Feders.l Gov"rn.'Ut.mt should. not hp.ve to c1.rry the burdon of Iitigaticn. To thf~ greatE3st deSTt.f;3 possible, these: righL.s should be

determined buforc construction of 3 projoct is st~rted9

There arc arch1ic water codes in savaral States wri.ch should be; overlvluled~ Today's r€-cl.:-mLl. tion dE:velopmGnt.s are P.. far cry from those pro l8Cts c~ hnlf centU!'y ·3.nd more ago for which man:". ezisting water codes

V[(;1"8 designed., 'lnd the;{ ShO"ll.d be brought up to d;'tte~ This is particulg.rly

tru0 cO:lcvr~'nn[!, th<:, codes for ground V!2,tel' .':'..lld its use.

E~gion~l Director E. O. L~rson from Salt Lake City, whom n~ny of

y.11 knoll'" ";ri.ll have lnore to say on this subjE.~ct tomorro'.'v and I urge :rou to ~c;1sider his ideas carefully.

Th:-..so, then, are some of the: '\'la"~/s in vihi.ch you can keep the

coiling unli:ni t6C. on western growth and pro3pc..rity by a continuing recla.ma-tion r)ro~:r<:.m. 1'1'1~ noed for j.t is solf-evidc,nt.

Onu ha~ i)llJ.y to takt0 a look cl.t the hU?1dreds and thousands of

applicatioIls fro;-;l ':;2r votur'ans for the very J.imi t'··d nu.rnh8r of irrigated bom:stlJad farm~ to get an idea of the prcsEUl'(j vjhich ~xists to gat a pic'--'e of good, pro1uctiv,:.. farm land. Th6so young pcopl~~ v:ould make desirA.blc additions to any communit:r in the l'h·;st$

Yet, during this lc.lE:t sprin~: ri.nd sur.illlc:r, Vi2; V'Jur<) abl(~ to opEm to

homestead just 306 farms comprisir~ 22,400 acrdQ

• Thore y~8 an average of

77 applicati ons for cacli farm, 'The' need for r.1oro faryrling opportuni ti.cs is self-evident.

There" is also looming again in tho.. W..;st, aftbr s8veral renerally good water years, the ugly specter of drouth. The Facific So' th~~r(;st

particularly has been short of irrigation water for sov~ral years and the south(,rn area east of th'3 Rocki.es f01 t the hard pinch of 'V'lil ted crops and

dry, dusty farm lands.. It is anyone's ':;'J.GSE where drouth will strike next .. You can't build an irri['ation project tomorrow, to care of today's drouth"

But with your full parti'cipation and coopcration, we wiIl have nm'v acreage coming under irrigation each yovar and lTlor -,; r:·..sorvoir storage space and facilit'i,~s to serve that acr-aagu as vtcll as to }:clp O.lit where

present sources are insufficient. xx

6

Paper Presented at 22nd Annual Convention National Reclamation Association

Reno, Nevada, October

15, 1953

by Robin R. Reynolds, Senior Hydraulic Engineer Division of Water Resources, Department of Public Works

state of California

AN EVALUATION OF WEATHER MODIFICATION OPERATIONS IN CALIFORNIA

The Division of Water Resourc~s is presently conducting studies leading to a revision and completion of the state Water Plan, for and under direction of the California State Water Resources Board. The objective of this investigation is the preparation of a plan for full conservation, control, and utilization of the Statets water resources, both surface and underground, to meet present and future water needs for all beneficial purposes and uses in all areas of the State insofar as practical. This has been designated The California Water Plan.

A necessary part of these studies includes an assessment of the adequacy and availability of the fresh water resources of each area of the State. The fresh water resources include precipitation in its many forms, runoff of surface streams, and underground waters. These water resources exhibit both geographic and seasonal deficiencies and variations which are restrictive and occassionally disastrous, and any developments which might increase the availability of exist-ing water resources or provide for new ones would be of the utmost importance. Recent technological advances have called attention to sea-water conversion and to endeavors popularly tenned "rainmaking" as possible means of adding to Cali-forniats water resources. These possible, additional resources of water are being given consideration in planning insofar as possible and insofar as they are shown to provide dependable water.

In connection with studies of The California Water Plan, data on weather modification have been collected since about

1946.

In

1951

the Legislature

-1-Paper Presented at 22nd Annual Convention National Reclamation Association

Reno, Nevada, October

15, 1953

by Robin R. Reynolds, Senior Hydraulic Engineer Division of Water Resources, Department of Public Works

state of California

AN EVALUATION OF WEATHER MODIFICATION OPERATIONS IN CALIFORNIA

The Division of Water Resourc~s is presently conducting studies leading to a revision and completion of the state Water Plan, for and under direction of the California State Water Resources Board. The objective of this investigation is the preparation of a plan for full conservation, control, and utilization of the Statets water resources, both surface and underground, to meet present and future water needs for all beneficial purposes and uses in all areas of the State insofar as practical. This has been designated The California Water Plan.

A necessary part of these studies includes an assessment of the adequacy and availability of the fresh water resources of each area of the State. The fresh water resources include precipitation in its many forms, runoff of surface streams, and underground waters. These water resources exhibit both geographic and seasonal deficiencies and variations which are restrictive and occassionally disastrous, and any developments which might increase the availability of exist-ing water resources or provide for new ones would be of the utmost importance. Recent technological advances have called attention to sea-water conversion and to endeavors popularly tenned "rainmaking" as possible means of adding to Cali-forniats water resources. These possible, additional resources of water are being given consideration in planning insofar as possible and insofar as they are shown to provide dependable water.

In connection with studies of The California Water Plan, data on weather modification have been collected since about

1946.

In

1951

the Legislature

-1-supplemented this study with an appropriation specifically for an evaluation of weather modification operations. It has been requested that I briefly outline to you today the progress and prelimina~ findings of this investigation.

Before proceeding with the discussion of evaluation it will be worth-while to point out a few pertinent facts of general interest. As you all know" the first of the current weather modification experiments were performed in the General Electric Laborator.y in

1946

and commercial efforts to modi~ clouds and increase rainfall followed soon thereafter. Based on prior theoretical investi-gations and subsequent physical experiments, some lmowledge and understanding of the processes which cause precipitation~been revealed. While this understand-ing is by no means complete at the present time, it is thought that the original nucleus of the raindrop is necessarily an ice c~stal. Current weather modifica-tion operamodifica-tions are based upon an assumpmodifica-tion there is a lack of natural ice crys-tals in the atmosphere to provide sufficient nuclei at certain times to sustain prolonged rain.

In 19~2, approximately 17 per cent of the area of California was under

contract for rainmaking operations and a much greater area was probably affected. The total funds involved probably amounted to from $175,000 to $200,000. At the same time about 20 per cent of tbe entire United states was under contract for cloud-seeding operations. In California these operations covered the County of San Diego, the Santa Ana River Basin, the Upper Owens Valley, Antelope Valley, Ventura County, Santa Barbara County, portions of the Southern San Joaquin Valley in the vicinities of Taft and Porterville, the Florence-Huntington Lake area, the County of Santa Clara, and the Grass Valley-Auburn area. There is somewhat less activity at the present time due mainly to the cancellation of operations by

vol-unta~ farmer groups. However, it is interesting to note that on the West Coast operations are being conducted by Washington ~ater-Power Company, Pacific Power and Light, California-Oregon Power Company, Pacific Gas and Electric Company,

-2-supplemented this study with an appropriation specifically for an evaluation of weather modification operations. It has been requested that I briefly outline to you today the progress and prelimina~ findings of this investigation.

Before proceeding with the discussion of evaluation it will be worth-while to point out a few pertinent facts of general interest. As you all know" the first of the current weather modification experiments were performed in the General Electric Laborator.y in

1946

and commercial efforts to modi~ clouds and increase rainfall followed soon thereafter. Based on prior theoretical investi-gations and subsequent physical experiments, some lmowledge and understanding of the processes which cause precipitation~been revealed. While this understand-ing is by no means complete at the present time, it is thought that the original nucleus of the raindrop is necessarily an ice c~stal. Current weather modifica-tion operamodifica-tions are based upon an assumpmodifica-tion there is a lack of natural ice crys-tals in the atmosphere to provide sufficient nuclei at certain times to sustain prolonged rain.

In 19~2, approximately 17 per cent of the area of California was under

contract for rainmaking operations and a much greater area was probably affected. The total funds involved probably amounted to from $175,000 to $200,000. At the same time about 20 per cent of tbe entire United states was under contract for cloud-seeding operations. In California these operations covered the County of San Diego, the Santa Ana River Basin, the Upper Owens Valley, Antelope Valley, Ventura County, Santa Barbara County, portions of the Southern San Joaquin Valley in the vicinities of Taft and Porterville, the Florence-Huntington Lake area, the County of Santa Clara, and the Grass Valley-Auburn area. There is somewhat less activity at the present time due mainly to the cancellation of operations by

vol-unta~ farmer groups. However, it is interesting to note that on the West Coast operations are being conducted by Washington ~ater-Power Company, Pacific Power and Light, California-Oregon Power Company, Pacific Gas and Electric Company,

-2-Southern California Edison, and California Electric Power Company. The Bonnevi11e Power Administration also had a program in the fall of 1951.

Bills aimed at evaluating or regulating weather modification operations have been presented to the last two sessions of Congress. However, up to the present time none of these have been enacted into law. However, in California, three laws regarding cloud-seeding were enacted in 1951. The first of these amended the Riverside County Flood Control and Water Conservation District Act to allow the District to levee a tax to conduct cloud-seeding operations. The second of these laws appropriated funds to the State .Water Resources Board to investigate rainmaking operations and the third of these laws requires that all persons con-ducting cloud-seeding operations in California obtain a license from the State Engineer, publish local notices of intention, submit records of their operations to the office of the State Engineer, and perform evaluations of their operations.

In addition to statistical cautions, several other basic difficulties arise when an attempt is made to subject existing climatological data to analysis to solve this problem. The mass of climatological data collected for the past half-century is satisfactor,y for large-scale climatological and meteorological studies, for locating cyclones and anticyclones, storm fronts, and air mass move-ments. Whether these data are too scattered or contain inherent observational

which preclude their use

errors/to solve our problem, is not known. Another more immediate_~roblem also arose during the investigation. Since October, 1951, and until recently the of-£icia1 records at

267

automatic raingages in the Eydroc1imatic Network in Ca1i-fornia were not available. Until July 1, 1951, funds for the operation of these gages were transferred to the U. S. Weather Bureau by the Corps of Engineers when reduction of the Engineers appropriation precluded continuation of the agreement. The agreement was resumed in the 1953 fiscal year and the work is now running ap-proximately one year behind. Lack of this data, the processing of which requires in California an estimated $40,000 per year, together with the limited coverage

-3-Southern California Edison, and California Electric Power Company. The Bonnevi11e Power Administration also had a program in the fall of 1951.

Bills aimed at evaluating or regulating weather modification operations have been presented to the last two sessions of Congress. However, up to the present time none of these have been enacted into law. However, in California, three laws regarding cloud-seeding were enacted in 1951. The first of these amended the Riverside County Flood Control and Water Conservation District Act to allow the District to levee a tax to conduct cloud-seeding operations. The second of these laws appropriated funds to the State .Water Resources Board to investigate rainmaking operations and the third of these laws requires that all persons con-ducting cloud-seeding operations in California obtain a license from the State Engineer, publish local notices of intention, submit records of their operations to the office of the State Engineer, and perform evaluations of their operations.

In addition to statistical cautions, several other basic difficulties arise when an attempt is made to subject existing climatological data to analysis to solve this problem. The mass of climatological data collected for the past half-century is satisfactor,y for large-scale climatological and meteorological studies, for locating cyclones and anticyclones, storm fronts, and air mass move-ments. Whether these data are too scattered or contain inherent observational

which preclude their use

errors/to solve our problem, is not known. Another more immediate_~roblem also arose during the investigation. Since October, 1951, and until recently the of-£icia1 records at

267

automatic raingages in the Eydroc1imatic Network in Ca1i-fornia were not available. Until July 1, 1951, funds for the operation of these gages were transferred to the U. S. Weather Bureau by the Corps of Engineers when reduction of the Engineers appropriation precluded continuation of the agreement. The agreement was resumed in the 1953 fiscal year and the work is now running ap-proximately one year behind. Lack of this data, the processing of which requires in California an estimated $40,000 per year, together with the limited coverage

-3-in critical areas afforded by even this extensive network seriously hampered and delayed the rainmaking investigation in California. Considering the uncertainty about the continued availability of these funds, it is unfortunate that the Wea-ther Bureau, unlike certain agencies such as the Bureau of Public Roads and the Geological Survey, is not, under present laws, permitted to accept funds either under a complete or partial support basis, from nonfederal agencies. This latter condition prevents states and other public agencies from obtaining supplemental meteorological data for use in s~ecial hydrologic investigations and suggests the need for a change in the basia legislation under which the Weather Bureau operates. The close coordination and excellent results which may be obtained by cooperative effort are demonstrated by the long and successful history of the program between the Geological Surve,y and the various states in the fields of surface water sup-ply and topographic mapping.

As an agency of the Department of Commerce, it is the responsibility of the Weather Bureau to collect and disseminate, at Federal expense, meteorological data needed for activities in connection with interstate commerce and to establish and maintain an adequate basic meteorological network to meet its statutory re-quirements for agricultural forecasting and issuance of flood warnings. Adequate funds to perform these duties should be allocated-directly to the Weather Bureau by Congress. Therefore, it is recommended that the National Reclamation Associa-tion endorse a resoluAssocia-tion calling for the enactment of legislaAssocia-tion at the Federal level, which would require that adequate funds for basic meteorological services be appropriated directly to the Weather Bureau, and additional legislation which would permit cooperative agreements between the Weather Bureau and nonfederal

agencies providing for special services which the trained personnel of the Weather Bureau are most capable of perfor.ming.

Now, with this introduction to the subject as background, let us discuss the controversial and difficult subject of evaluation. As a first step, let us

-4-in critical areas afforded by even this extensive network seriously hampered and delayed the rainmaking investigation in California. Considering the uncertainty about the continued availability of these funds, it is unfortunate that the Wea-ther Bureau, unlike certain agencies such as the Bureau of Public Roads and the Geological Survey, is not, under present laws, permitted to accept funds either under a complete or partial support basis, from nonfederal agencies. This latter condition prevents states and other public agencies from obtaining supplemental meteorological data for use in s~ecial hydrologic investigations and suggests the need for a change in the basia legislation under which the Weather Bureau operates. The close coordination and excellent results which may be obtained by cooperative effort are demonstrated by the long and successful history of the program between the Geological Surve,y and the various states in the fields of surface water sup-ply and topographic mapping.

As an agency of the Department of Commerce, it is the responsibility of the Weather Bureau to collect and disseminate, at Federal expense, meteorological data needed for activities in connection with interstate commerce and to establish and maintain an adequate basic meteorological network to meet its statutory re-quirements for agricultural forecasting and issuance of flood warnings. Adequate funds to perform these duties should be allocated-directly to the Weather Bureau by Congress. Therefore, it is recommended that the National Reclamation Associa-tion endorse a resoluAssocia-tion calling for the enactment of legislaAssocia-tion at the Federal level, which would require that adequate funds for basic meteorological services be appropriated directly to the Weather Bureau, and additional legislation which would permit cooperative agreements between the Weather Bureau and nonfederal

agencies providing for special services which the trained personnel of the Weather Bureau are most capable of perfor.ming.

Now, with this introduction to the subject as background, let us discuss the controversial and difficult subject of evaluation. As a first step, let us

-4-make clear what an evaluation study can and cannot achieve. As stated by Dr. J. Neyman, Director of the Statistical Laborato~of the University of California and Special Consultant for the rairunaking investigation, "it must be obvious at once that no stu~ whatever

can

provide evidence that it is impossible to produce or increase rainfall by artificial means. Even though no rain is produc~din a series of experiments, there is always the possibility that the failures are due either to faults in technique, that can be understood and corrected, or to unfav-orable weather conditions, which may change, or to maladjustment between the var-ious methods emplqyed and the prevailing atmospheric conditions. It follows that, whatever conclusions a stuQy may suggest, these conclusions must apply specifically to such rainmaking techniques as were used in the trials and in relation to the conditions which prevailed during the trials."

The "next remark, also of a negative character" refers to the question of the certainty of a conclusion "in the case of a rainmaking experiment. The only case where such a conclusion is definite, is when cloud-seeding is not fol-lowed by any precipitation. In cases of this kind the obvious and safe conclusion is that, in these particular conditions the particular techniques used gave nega-tive results. However, it must be understood that this is no evidence against the possibility that the same technique might produce precipitation, perhaps in slight-ly different conditions.

"The possibility of a definite conclusion disappears entirely if the cloud-seeding operations are followed by precipitation. The reason is that it is impossible to make certain that the same precipitation would not have fallen if there were no cloud-seeding. Great as this difficulty is, its importance should not be over-emphasized, because it exists and is being overcome in all branches of natural science. A patient suffering from a disease is given a shot of peni-cillin and recovers. Did he recover because of the shot received or in spite of this shot? This question can never be answered with certainty and no answer of

-,-make clear what an evaluation study can and cannot achieve. As stated by Dr. J. Neyman, Director of the Statistical Laborato~of the University of California and Special Consultant for the rairunaking investigation, "it must be obvious at once that no stu~ whatever

can

provide evidence that it is impossible to produce or increase rainfall by artificial means. Even though no rain is produc~din a series of experiments, there is always the possibility that the failures are due either to faults in technique, that can be understood and corrected, or to unfav-orable weather conditions, which may change, or to maladjustment between the var-ious methods emplqyed and the prevailing atmospheric conditions. It follows that, whatever conclusions a stuQy may suggest, these conclusions must apply specifically to such rainmaking techniques as were used in the trials and in relation to the conditions which prevailed during the trials."

The "next remark, also of a negative character" refers to the question of the certainty of a conclusion "in the case of a rainmaking experiment. The only case where such a conclusion is definite, is when cloud-seeding is not fol-lowed by any precipitation. In cases of this kind the obvious and safe conclusion is that, in these particular conditions the particular techniques used gave nega-tive results. However, it must be understood that this is no evidence against the possibility that the same technique might produce precipitation, perhaps in slight-ly different conditions.

"The possibility of a definite conclusion disappears entirely if the cloud-seeding operations are followed by precipitation. The reason is that it is impossible to make certain that the same precipitation would not have fallen if there were no cloud-seeding. Great as this difficulty is, its importance should not be over-emphasized, because it exists and is being overcome in all branches of natural science. A patient suffering from a disease is given a shot of peni-cillin and recovers. Did he recover because of the shot received or in spite of this shot? This question can never be answered with certainty and no answer of

-,-this kind is expected. The question which we are accustomed to have asked (and to have answered) is how frequently patients with a specified diagnosis recover without the injection of the penicillin and how frequently they recover after re-ceiving an injection. It must be clear that the best possible solution of the problem of artificial rainmaking must be couched in similar terms•••• lt must suf-fice, therefore, that the outcome of a statistical study of rainmaking operations must inevitably take one of the following (or similar) forms:

(i) In relation to (the specified) conditions and with the risk of error not exceeding 1 per cent (or some such small limit), it is possible to assert that cloud-seeding operations result, on the average, in an increase in precipitation of at least 10 (or some such figure) per cent.

(ii) Without risking an error in judgment more frequent than 1 per cent (or some such small limit), it is impossible to assert that, in the specified con-ditions, eloud-seeding operations result in any increase in precipitation_"

Now, as a second step let us evaluate a hypothetical rainmaking experi-ment. Let us assume that rainmaking operations are being conducted outside this building at the present time and that we desire to evaluate the results of the operation. A first and rather obvious way would be to compare the resulting rain-fall with the official weather forecast. We wrongly discredit this method, but it is important to mention, because our more sophisticated attempts at evaluation will be of the same comparison type. The weather forecaster may even have an ad-vantage because he is permitted to subjectively weigh' different factors. Another and obvious method would be to conduct a survey within the target area and to in-quire about the results that had been observed by persons familiar with the area. A considerable amount of positive visual, and psychological evidence could proba-bly be collected in this maImer. The statements would generally be that "when the silver iodide generator was on it began to rain", "when it was off, it quit", "when it was turned on it started to rain", etc. Other statements might point out tha.t

-6-this kind is expected. The question which we are accustomed to have asked (and to have answered) is how frequently patients with a specified diagnosis recover without the injection of the penicillin and how frequently they recover after re-ceiving an injection. It must be clear that the best possible solution of the problem of artificial rainmaking must be couched in similar terms•••• lt must suf-fice, therefore, that the outcome of a statistical study of rainmaking operations must inevitably take one of the following (or similar) forms:

(i) In relation to (the specified) conditions and with the risk of error not exceeding 1 per cent (or some such small limit), it is possible to assert that cloud-seeding operations result, on the average, in an increase in precipitation of at least 10 (or some such figure) per cent.

(ii) Without risking an error in judgment more frequent than 1 per cent (or some such small limit), it is impossible to assert that, in the specified con-ditions, eloud-seeding operations result in any increase in precipitation_"

Now, as a second step let us evaluate a hypothetical rainmaking experi-ment. Let us assume that rainmaking operations are being conducted outside this building at the present time and that we desire to evaluate the results of the operation. A first and rather obvious way would be to compare the resulting rain-fall with the official weather forecast. We wrongly discredit this method, but it is important to mention, because our more sophisticated attempts at evaluation will be of the same comparison type. The weather forecaster may even have an ad-vantage because he is permitted to subjectively weigh' different factors. Another and obvious method would be to conduct a survey within the target area and to in-quire about the results that had been observed by persons familiar with the area. A considerable amount of positive visual, and psychological evidence could proba-bly be collected in this maImer. The statements would generally be that "when the silver iodide generator was on it began to rain", "when it was off, it quit", "when it was turned on it started to rain", etc. Other statements might point out tha.t

-6-the rain which fell during -6-the cloud-seeding operation was -6-the most unusual, -6-the heaviest, the most unseasonal, or the most concentrated rain that had ever occurred within the memo~ of the observer, or the observer's father or grandfather, etc. Or the observations might claim that rain was seen to begin immediately following the passing of the airplane distributing dr,y ice. Are observations of this type valuable or conclusive evidence? In general, it can be said that the observations themselves might ver,y well be correct. However, the likelyhood of their happening naturally is not known and furthermore, it is certainly possible by close inspec-tion to note or observe in the weather any phenomenon one wishes to see.

Another method of evaluation would be to plot on a map the rainfall at every station in the target and surrounding area for the particular storm. On this map it would be noted that centers or local concentrations of rainfall occur as with every storm. If this center of rainfall occurred in the target area in a seeded storm, would that fact be documentary evidence of the effectiveness of cloud-seeding? It would not be documentary evidence because, again the likelyhood of its happening naturally is actually not known. However, it is admitted that if the center of rainfall did occur in the target area consistently and over a long period during cloud-seeding experiments, this fact would become "very inter-esting". This evaluation technique has been used by many operators and was con-sidered in the current studies. However, it was observed by actual inspection of rainfall maps that there is no general uniformity in the location of the centers of rainfall. Often the operator attributes any center of rainfall in the vicinity of the target area to a successful rainmaking operation with the added statement that due to lack of complete control the target area was missed somewhat. In

argument against this claim, inspection of historic maps will show rainfall centers distributed in similar and in probably more interesting fashions than during the rainmaking operations.

A fourth method of evaluation and one that was used in a modified form

-7-the rain which fell during -7-the cloud-seeding operation was -7-the most unusual, -7-the heaviest, the most unseasonal, or the most concentrated rain that had ever occurred within the memo~ of the observer, or the observer's father or grandfather, etc. Or the observations might claim that rain was seen to begin immediately following the passing of the airplane distributing dr,y ice. Are observations of this type valuable or conclusive evidence? In general, it can be said that the observations themselves might ver,y well be correct. However, the likelyhood of their happening naturally is not known and furthermore, it is certainly possible by close inspec-tion to note or observe in the weather any phenomenon one wishes to see.

Another method of evaluation would be to plot on a map the rainfall at every station in the target and surrounding area for the particular storm. On this map it would be noted that centers or local concentrations of rainfall occur as with every storm. If this center of rainfall occurred in the target area in a seeded storm, would that fact be documentary evidence of the effectiveness of cloud-seeding? It would not be documentary evidence because, again the likelyhood of its happening naturally is actually not known. However, it is admitted that if the center of rainfall did occur in the target area consistently and over a long period during cloud-seeding experiments, this fact would become "very inter-esting". This evaluation technique has been used by many operators and was con-sidered in the current studies. However, it was observed by actual inspection of rainfall maps that there is no general uniformity in the location of the centers of rainfall. Often the operator attributes any center of rainfall in the vicinity of the target area to a successful rainmaking operation with the added statement that due to lack of complete control the target area was missed somewhat. In

argument against this claim, inspection of historic maps will show rainfall centers distributed in similar and in probably more interesting fashions than during the rainmaking operations.

A fourth method of evaluation and one that was used in a modified form

-7-in our f-7-inal studies is to compare the ra-7-infall -7-in the target area with simultan-eous rainfall in another remote area unaffected by the operation. To accomplish this the amount of rainfall occurring in the two areas is plotted on a simple co-ordinate system. The relation between rainfall in the two areas is determined by plotting the points representing a large number of storms occurring during

non-seeded years. The points representing the seeded storms are then superimpo~edon this diagram and a decision or statistical test is made as to whether the varia-tion is greater than might be expected. It can be seen that there is a continuous variation in rainfall amounts for the historic storms from those giving no rain in the target area to those giving no rain in the control area, and any storm, between these two extremes, can be compared with a more extreme value.

This method was modified by dividing the storms into classes which range in general from a class of storms giving more rain in the target area and less in the control area, to those giving more rain in the control area and less in the target area. The seeded storms are then classified in the same manner and the points again superimposed on the diagram showing the relation for that type of storm.

The results of this analysis are interesting and are summarized in the following table for three separate areas in California.

PROBABILITY THAT RELATION FOR SEEDED STORMS WAS ACTUALLY DIFFERENT FROM THAT FOR FIVE UNSEEDED YEARS

Northern Intermediate

Southern-Area storms storms storms

Carrizo Plains n.s. n.s. 0.95 (negative)

62

storms

Southern Sierra n.s. n.s. n. s.

24

stoms

Santa Barbara County

53

storms

Subarea I n.s. 0.990 n.s.

II n.s. >0.999 n. s.

III n.s. 0.970 n. s.

IV n.s. >0.990 n.s.

n.s. - Not significant at 0.90 level.

-8-in our f-8-inal studies is to compare the ra-8-infall -8-in the target area with simultan-eous rainfall in another remote area unaffected by the operation. To accomplish this the amount of rainfall occurring in the two areas is plotted on a simple co-ordinate system. The relation between rainfall in the two areas is determined by plotting the points representing a large number of storms occurring during

non-seeded years. The points representing the seeded storms are then superimpo~edon this diagram and a decision or statistical test is made as to whether the varia-tion is greater than might be expected. It can be seen that there is a continuous variation in rainfall amounts for the historic storms from those giving no rain in the target area to those giving no rain in the control area, and any storm, between these two extremes, can be compared with a more extreme value.

This method was modified by dividing the storms into classes which range in general from a class of storms giving more rain in the target area and less in the control area, to those giving more rain in the control area and less in the target area. The seeded storms are then classified in the same manner and the points again superimposed on the diagram showing the relation for that type of storm.

The results of this analysis are interesting and are summarized in the following table for three separate areas in California.

PROBABILITY THAT RELATION FOR SEEDED STORMS WAS ACTUALLY DIFFERENT FROM THAT FOR FIVE UNSEEDED YEARS

Northern Intermediate

Southern-Area storms storms storms

Carrizo Plains n.s. n.s. 0.95 (negative)

62

storms

Southern Sierra n.s. n.s. n. s.

24

stoms

Santa Barbara County

53

storms

Subarea I n.s. 0.990 n.s.

II n.s. >0.999 n. s.

III n.s. 0.970 n. s.

IV n.s. >0.990 n.s.

n.s. - Not significant at 0.90 level.

-8-The above table indicates that in the Carrizo Plains cloud-seeding apparently resulted in a substantial decrease in rainfall expected from souther~ storms, that the storms in the Southern Sierra area were not significantly af-fected, and that in Santa Barbara County there were apparently high~ significant increases in rainfall from the intermediate storms. What would one infer from these results? In the first place, it may be, that in certain storms the rainfall is increased and in others it is decreased due to cloud-seeding. There are, how-ever, other possibilities. For instance, the seeded storms in Santa Barbara County typed as intermediate storms are probably actually a conglomeration of several subtypes with different properties and it is possible that a subtype tending to resemble the southerly storms, which favor the target area, may have predominated. There are also statistical objections of a conceptual nature having to do with normal distributions and the validity of historic relations. However, within the statistical framework and for the particular years which were used, the rainfall increases in Santa Barbara County are significant.

From this evidence then, you must make your own subjective decision as to the effectiveness of weather modification operations. It must be admitted that no documentary evidence has yet been produced either to prove or disprove the claims of the rainmakers.

Is it possible to obtain documentary evidence of the effectiveness of cloud-seeding? The results of these and other studies indicate that it is possi-ble. It is indicated that a properly designed experiment conducted over a period of several years would probably yield positive results. The experiment would be conducted by seeding only part of the storms as they occurred, thus enabling the determination of the stability of the seeded-nonseeded relation throughout the experiment. How long would the eJq)eriment require? The experiment should proba-bly not be expected to yield categorical results in less than

5

to 10 years. Is it worthwhile to pursue this evaluation? Certainly it is. The results of even

-9-The above table indicates that in the Carrizo Plains cloud-seeding apparently resulted in a substantial decrease in rainfall expected from souther~ storms, that the storms in the Southern Sierra area were not significantly af-fected, and that in Santa Barbara County there were apparently high~ significant increases in rainfall from the intermediate storms. What would one infer from these results? In the first place, it may be, that in certain storms the rainfall is increased and in others it is decreased due to cloud-seeding. There are, how-ever, other possibilities. For instance, the seeded storms in Santa Barbara County typed as intermediate storms are probably actually a conglomeration of several subtypes with different properties and it is possible that a subtype tending to resemble the southerly storms, which favor the target area, may have predominated. There are also statistical objections of a conceptual nature having to do with normal distributions and the validity of historic relations. However, within the statistical framework and for the particular years which were used, the rainfall increases in Santa Barbara County are significant.

From this evidence then, you must make your own subjective decision as to the effectiveness of weather modification operations. It must be admitted that no documentary evidence has yet been produced either to prove or disprove the claims of the rainmakers.

Is it possible to obtain documentary evidence of the effectiveness of cloud-seeding? The results of these and other studies indicate that it is possi-ble. It is indicated that a properly designed experiment conducted over a period of several years would probably yield positive results. The experiment would be conducted by seeding only part of the storms as they occurred, thus enabling the determination of the stability of the seeded-nonseeded relation throughout the experiment. How long would the eJq)eriment require? The experiment should proba-bly not be expected to yield categorical results in less than

5

to 10 years. Is it worthwhile to pursue this evaluation? Certainly it is. The results of even

-9-these ftinterestingrt _{evaluations are so interesting in certain cases as to make}

continued evaluation worthwhile.

-10-these ftinterestingrt _{evaluations are so interesting in certain cases as to make}

continued evaluation worthwhile.