276 P.2d 992 (1954)

CITY AND COUNTY OF DENVER, City of Colorado Springs, South Platte Water Users Association, Plaintiffs in Error,
v.
NORTHERN COLORADO WATER CONSERVANCY DISTRICT, Colorado River Water Conservation District, F. E. Yust, Clayton Hill, Grand Valley Irrigation Co., Grand Valley Water Users Association, Orchard Mesa Irrigation District and Palisade Irrigation District, Defendants in Error.

Nos. 16881, 16888.

Supreme Court of Colorado, En Banc.

October 18, 1954. Rehearing Denied December 13, 1954. On Supplemental Motions and Petition for Rehearing January 14, 1955.

*995 Leonard M. Campbell, Glenn G. Saunders, John P. Akolt, Robert A. Dick, Harold D. Roberts, Milton J. Keegan and John M. Dickson, Denver, for plaintiff in error, City and County of Denver.

F. T. Henry, Colorado Springs, A. W. McHendrie, Pueblo, for plaintiff in error, City of Colorado Springs.

William W. Gaunt, Brighton, for plaintiff in error, South Platte Water Users Ass'n.

William R. Kelly, and John R. Clayton, Greeley, for defendant in error, Northern Colorado Water Conservancy Dist.

Frank Delaney, Glenwood Springs, for defendants in error, Clayton Hill and Colorado River Water Conservation Board.

John B. Barnard, John B. Barnard, Jr., and Duane L. Barnard, Granby, for defendant in error, F. E. Yust.

Guy V. Sternberg, Grand Junction, for defendant in error, Grand Valley Irrigation Co.

Silmon Smith and Charles Holmes, Grand Junction, for defendants in error, Grand Valley Water Users Ass'n, Orchard Mesa Irr. Dist., Palisade Irr. Dist.

STONE, Chief Justice.

Under our Colorado Statutes for adjudication of water rights, two proceedings were brought in Water District No. 36: one for adjudication of rights for irrigation, and the other for adjudication of rights for purposes other than irrigation. These proceedings were consolidated for trial in the court below and are considered together here.

The water rights involved are from the Blue River, a stream located on the Western Slope of the Continental Divide in Colorado, and a tributary of Colorado River. We have here for review the decree of the trial court as to priorities awarded to the water project of the City of Denver and that of the City of Colorado Springs and the refusal of priority to the project of South Platte Water Users Association, all situate on the Eastern Slope of the Continental Divide and all proposing to divert water by means of tunnels through the Divide, and also the refusal of priority to the Green Mountain Reservoir and hydroelectric plant, which had been sought at first by the United States of America and later by the Colorado River Water Conservation District.

In considering these conflicting claims, the Court must be concerned not with the oratorical hyperboles of council, or the alarming prophecies of partisans in the Press, or our own opinions as to comparative value of use, but only with the facts in the record, the questions argued before the Court and the application of established rules of law to the adjudication of the respective property rights in the waters of said stream.

First, considering the provisions of the decree adjudicating the rights of the Denver Blue River project:

By its statement of claim in the proceedings before us, Denver asserted right of priority to its Blue River project, both for direct use and for storage of various amounts in its several reservoirs. To the Dillon Reservoir, only, was awarded a conditional *996 decree, which was for the full amount sought, but of later date. No challenge is made or argument presented before us concerning the decree to the Dillon Reservoir or concerning the failure of the trial court to award decrees to the other reservoirs; the only issues presented in behalf of Denver concern the award to its Blue River diversion project for direct use. Claim was made therefor in the amount of 1600 second feet as of date of March 21, 1914, and conditional decree was awarded therefor in the amount of 788 second feet as of June 24, 1946.

A brief summary from the record of the steps taken by Denver in connection with the intended appropriation of water from the Blue River is necessary to understand the issue presented. Denver is located on the Eastern Slope of the Continental Divide. As early as 1914 there began to be envisioned future shortage of water supply and the need for supplemental water from the tributaries of the Colorado River on the Western Slope of the Divide. A preliminary reconnaissance of the Blue River basin was made in that year, but nothing further appears to have been done until 1921 when a consulting water engineer was employed to investigate possible diversion of water from the Western Slope. On July 4, 1921, he began field work in the Fraser River basin and during the same summer did work in the Williams Fork basin. As a result of his work in these basins, the Williams Fork and Fraser River water diversion projects were planned and have since been largely consummated, and water rights have been decreed by virtue of diversion therethrough.

Sometime in the summer of 1922, preliminary surveys were made for the purpose of filing on the Blue River and its tributaries. Thereafter the office work was done and filing made in the office of the state engineer on May 31, 1923. The plat then filed showed a proposed transmountain tunnel to bring waters from the south fork of the Swan River, a tributary of the Blue, through the Continental Divide to Jefferson Creek, a tributary of the South Platte River, on the Eastern Slope. It was introduced in evidence by Denver as its Exhibit A.

In 1926 it was determined to investigate locating an intake at a much lower elevation which would involve less difficulty and expense for collection ditches and collect water from a larger drainage area. Accordingly, a survey was made in that year and plat filed with the state engineer in 1927 for a proposed diversion directly from the Blue River by means of a transmountain tunnel extending from Dillon on the Blue River to Grant on the north fork of the South Platte River. By that plan, in addition to the waters of the Blue and its tributaries which could be captured under the earlier plan, there could be diverted also the water from Ten Mile Creek by virtue of a short collection ditch, and the water of Snake Creek by virtue of a short feeder tunnel, both leading into the main transmountain tunnel. This second plat was introduced by Denver as its Exhibit B.

Geologizing of the tunnel site and geophysical work through subsequent years disclosed obstacles to the construction of this second tunnel, as originally proposed, with the result that the geologist in charge reported unfavorably thereon. Accordingly, it was proposed again to change the plan and to construct an angled instead of a straight-line tunnel a half mile longer. This is referred to as the Montezuma tunnel. This new site was geologized in the years 1943 to 1945. However, no plat appears to have been filed in the office of the state engineer or submitted in evidence showing the date of survey or the proposed location of the tunnel as so planned. In 1941 it was proposed to construct a large channel reservoir at the upper portal of the tunnel, located at the confluence of the Blue, the Ten Mile and the Snake. Adoption of this new plan would eliminate the need for any collection tunnels or ditches; provide storage during flood stage, and stabilize the supply. It necessitated a change in the proposed location of the tunnel of approximately twenty feet in elevation and of about three thousand five hundred feet in the point of intake. The large reservoir so proposed was designated as the Dillon *997 Reservoir and a plat showing the plan for it was filed in the office of the state engineer on November 14, 1942. This plat stated that work was commenced on features peculiar to storage therein on October 1, 1941. It was introduced as Denver's Exhibit D.

Still later, sometime between November 16, 1942, the time of filing Denver's claim in these proceedings, and July 1946, Denver's plan for the proposed tunnel was changed still again and it was decided to reduce its size and capacity from 1600 second feet to 788 second feet. In the latter year construction of a tunnel of 788 second feet capacity was actually begun and is still being prosecuted, and the trial court awarded to it a conditional decree in the amount of its capacity.

The Colorado River Water Conservation District and others protested the awarding of any decree whatever to Denver's Blue River project and here assign error to the decree awarded it on the ground that Denver now has an adequate water supply, and that a conditional decree should not be given for a larger quantity of water than it can reasonably expect to put to beneficial use. The uncontradicted evidence in the record discloses that Denver had adequate water supply at the time of the hearing without the Blue River water here sought. As to its further growth and consequent future need, there were divergent estimates, all necessarily without actual knowledge. We cannot hold that a city more than others is entitled to decree for water beyond its own needs. However, an appropriator has a reasonable time in which to effect his originally intended use as well as to complete his originally intended means of diversion, and when appropriations are sought by a growing city, regard should be given to its reasonably anticipated requirements. Van Tassel Real Estate & Livestock Co. v. City of Cheyenne, 49 Wyo. 333, 54 P.2d 906; City and County of Denver v. Sheriff, 105 Colo. 193, 96 P.2d 836. Particularly is this true in considering claims for conditional decrees. As was said in Taussig v. Moffat Tunnel Co., 106 Colo. 384, 106 P.2d 363, 367:

"* * * So long as no water has been applied to beneficial use, we are concerned only with an inchoate and an unperfected right. When the water is beneficially applied to a designated use, it becomes a property right and the decree then must take on the elements of definiteness and certainty. Such a situation is not now before us. Some of the problems raised may properly be determined when the question of entering a final decree is before the trial court or when they are specifically presented here for consideration."

While the witnesses as to Denver's future water requirements were not in agreement, there was substantial evidence to support a finding of future need for water from the Blue River within a reasonable time. This is amply confirmed by the City's rapid subsequent growth.

Denver, on the contrary, seeks modification of the decree herein as to its project, both by increasing the amount and awarding earlier priorities. Its argument is based on four asserted grounds, to wit:

"I. Denver Appropriated Water from the Blue River in 1921, Enlarged its Appropriation in 1927, Each Time in Amounts Reasonably Required to Meet its Needs.

"II. Denver has Exercised Due Diligence in the Development of the Blue River Unit of its Water System.

"III. Denver Could Lawfully Modify the Design of its Diversion System Without Loss of Priority.

"IV. A Decretal Order Should be Entered Relating to the Claim of the United States and Northern Colorado Water Conservancy District."

The last ground is the same as that asserted by the Colorado Water Conservation District and will be considered in that connection. The other grounds, in substance, assert claim to date back the priority of Denver's project in part to 1921 and in part to 1927 upon the ground that there has been due diligence in the development of the Blue River project since those dates *998 and no such change of plan as to prevent such dating back.

While not separately nor specifically asserted in its points argued, Denver contends that the court should have awarded to its Blue River project a total conditional decree for 1600 second feet, although its water is to be diverted and carried through a tunnel which is to have a final carrying capacity of only 788 second feet, the amount which was decreed to it by the trial court. Admittedly, there is no present intent or plan for a tunnel of capacity to divert more than 788 second feet from the stream, but it is asserted that the amount not diverted is to be stored temporarily in the channel reservoir or forebay at the tunnel entrance until the stream flow decreases so that the water there retained can be carried through. As stated in the Denver brief, "So in the final plan for Denver's Blue River unit the smaller bore tunnel operating at full capacity during about five months serves the same function as the bigger bore tunnel which would of necessity be working far below capacity at all times, except during the crest weeks of the early summer run-off. The forebay accomplishes no true storage, it merely feeds the direct flow water through the mountain at a uniform operating rate."

Counsel fail to mention that the "forebay" which is planned to hold the water from the early summer runoff in order to maintain the uniform flow during the later season, is in fact the proposed Dillon reservoir to be constructed in the channel of the Blue River at the headgate of the proposed tunnel, and that Denver sought and was awarded a storage decree to it in the amount of its full capacity. In other words, the "forebay" which "accomplishes no true storage" but is to hold the direct flow water until it can be taken through the tunnel, is at the same time to be the "reservoir" which is to hold water in "true storage" to its full capacity. One cannot add water to a full cup, and may not have a second decree for water from the same source to be held at the same time in the same reservoir to which a decree already has been awarded to its full capacity.

Further, the rule is elementary that the first essential of an appropriation is the actual diversion of the water with intent to apply to a beneficial use. "* * it has been repeatedly decided in this jurisdiction that an `appropriation' consists of an actual diversion of water from a natural stream, followed within a reasonable time thereafter by an application thereof to some beneficial use." Windsor Reservoir & Canal Co. v Lake Supply Ditch Co., 44 Colo. 214, 98 P. 729, 731. "Claimants, to gain a right to the use of a definite amount of water, must show that the quantity of water awarded them has been actually diverted, * * *." Pabst v. Finmand, 190 Cal. 124, 211 P. 11, 15. Water can be actually diverted only by taking it from the stream. The amount so diverted is necessarily limited to the capacity of the ditch or tunnel through which diversion is made. Where a tunnel is planned to have a capacity of only 788 second feet, only that amount can be diverted through it and any decree in excess of that amount would necessarily be a decree for water which had not been diverted and could not be diverted. Even if such a forebay may be considered as part of a system for direct use and is not given a decree for storage so that retention of water therein might be considered as diversion for direct use, the headgate and point of diversion for direct use would necessarily be at such forebay. Here, the decree for direct use provides for diversion at the three points higher up on the streams, as shown by Denver's map and statement, directly into the tunnel without mention of any forebay in connection therewith, and Denver asserts no error therein.

Denver's contention that decreased flow in a stream through the later season justifies a decree therefrom of a water right in excess of the capacity of its ditch is based on the ground that temporarily holding water in a channel reservoir through the early part of the season for use in the later season is not true storage. That contention is not sound. Virtually all streams in Colorado have such decreasing flow through the season, and most reservoirs are constructed for the purpose of *999 holding the excess early flow for use during the later season. "It is difficult to understand how the words `temporarily impound,' as applied to the storage of water in a reservoir to be used later for agricultural purposes, add anything to the nomenclature of the law of water. `Temporary' means lasting for a time only; it is opposed to permanent, but all water impounded in any storage reservoir is to be put there only temporarily; otherwise its capture from the stream must of necessity defeat the purpose of the law of beneficial user." Handy Ditch Co. v. Greeley & L. Co., 86 Colo. 197, 280 P. 481.

The statute recognizes two classes of appropriations for irrigation, one for ditches diverting water to be used directly from the stream, and one for the storage of water, to be used subsequently. Holbrook Irr. Dist. v. Ft. Lyon Canal Co., 84 Colo. 174, 269 P. 574. To the amount that water when available is to be diverted directly to its use, a direct use decree must be sought. To the amount that it is to be held in a reservoir for later use, a storage decree must be sought. Where water is stored in a channel reservoir, a ditch headed in such reservoir has no right by virtue of direct use decree to deplete such storage, but may properly take water from the reservoir by virtue of such decree only in the amount of the current inflow from sources subject to such direct use decree to the ditch.

There was no error in awarding to Denver's Blue River project for direct use a volume limited by the total proposed capacity of its diversion tunnel. The question of right of a city, after diversion, to store water diverted for domestic use is not here argued.

More serious questions are raised by Denver's challenge to the priority date awarded the Blue River project in the decree. The basic law is not disputed, to wit: (1) that priority of appropriation shall give the better right as between those using the water for the same purpose; (2) that as to the rights here involved a municipal corporation has no different status from that of an individual or any other party to the proceeding; (3) that although an appropriation is not complete until actual diversion and use, still, the right may relate back to the time when the first open step was taken giving notice of intent to secure it, Sieber v. Frink, 7 Colo. 148, 2 P. 901; Baca Irrigating Ditch Co. v. Model Land & Irrigation Co., 80 Colo. 398, 252 P. 358; (4) that right to relate back is conditional that construction thereafter was prosecuted with reasonable diligence, and conditional further that there was then "a fixed and definite purpose to take it up and carry it through," State of Wyoming v. Colorado, 259 U.S. 419, 42 S.Ct. 552, 567, 66 L.Ed. 999; Fruitland Irr. Co. v. Kruemling, 62 Colo. 160, 162 P. 161; and (5), that the questions of reasonable diligence and of fixed and definite purpose are questions of fact to be determined by the trial court from the evidence.

While Denver as yet has completed no appropriation of any water whatever from the Blue, it here seeks to have awarded to its Blue River project a conditional decree establishing by relation back the dates of filing its plats A and B as the dates of priority to which it contends it will ultimately be entitled. Determination of such date of priority must depend first upon the date when the first step was taken in connection with "the existence of a fixed and definite purpose," to carry it through, and second, upon its prosecution with reasonable diligence.

In each of the plats filed by Denver as its Exhibits A, B and D, it is recited that work was commenced by survey on the 21st day of March, 1914. In its statement of claim, Denver asserts the same commencement date. However, from the evidence submitted, it appears without dispute that the 1914 date was based entirely on reconnaissance surveys made in that year by the Public Utilities Commission not followed by any construction, and in its briefs Denver now abandons that date and claims right to conditional decree to the Blue River project for 1200 second feet as of July 4, 1921, and 400 cubic feet as of October 19, 1927, the former being the date when it is contended that survey was begun on a project *1000 planned to divert 1200 second feet, but some two years before filing any plat thereof, and the latter date being the date of the filing of its plat Exhibit B, showing plan to divert 1600 second feet.

There is no evidence that any work, even of survey, on the Blue River project was begun on July 4, 1921, or at any time prior to the summer of 1922. The claim for the 1921 date is based solely on the fact that survey was started on that date on Denver's Williams Fork and Fraser River projects and the contention that those two projects and the Blue River project constitute in fact a single irrigation project, and consequently that in the determination of the date when the first step was taken, and also in the determination of reasonable diligence since such date, the three projects should be considered as a single project.

In determining the date "when the first step was taken," a survey made on the Fraser River or on the Williams Fork would of itself be no evidence of intent to appropriate water from the Blue River. Certainly such a survey in a far distant basin supplying water to another stream would constitute no notice to another appropriator of such intent. The filing of a plat of method of diversion from the Fraser or Williams Fork would be no evidence of intent to appropriate water from the Blue or notice of such intent. Therefore, there is nothing to support the contention that the priority should be dated as of July 4, 1921. At most, the priority for the Blue River project could date back only to the time when the first step was taken in construction of a project on the Blue River.

In determining reasonable diligence, also, we find no ground for holding, as urged by Denver, that the Blue River project, the Williams Fork project and Fraser River project are each units of a single project so that the construction work on those projects and the expenses incurred thereon can be considered as part of the construction of the Blue River project. Denver's claim for its Blue River project was made by survey, plat and filing entirely separate from those of its Fraser and Williams Fork projects. It seeks priority to water from an entirely separate stream, not even confluent with the Fraser River or Williams Fork except to the extent that each is ultimately a tributary of the Colorado River. It seeks water to be diverted from an entirely separate drainage basin. It was surveyed and planned after those projects. It directly affects other claimants who are protestants here but not directly affected by those projects. It is to be carried through an entirely separate conduit,—the Fraser River being diverted through the Moffat Tunnel and the Williams Fork through the Jones Pass Tunnel, and the Blue, as now planned, to be carried in the Montezuma tunnel to be bored through the Continental Divide many miles to the south of the others. Its water rights are here sought to be adjudicated as entirely separate from the rights of those projects. It has even less relation to the Fraser River and Williams Fork projects than to Denver's South Platte water system with which it will share the same river channel and reservoirs. In fact, the only relation between the Blue River project and these other projects is that their several waters may ultimately rest in common filtration and concentration plants, and that by means of exchange they may be used cooperatively for supplying prior rights or filling storage reservoirs such as would be probable in the case of any other independent water right. The priority of appropriation which gives the better right under our Constitution is priority on a stream rather than on a project, and any diligence in construction to permit dating back of priority on the Blue River must be diligence relating to and promoting the Blue River appropriation. No such relation here appears. Therefore, diligence in the prosecution of the Fraser and Williams Fork projects cannot be imputed to the Blue River project. However, the fact that the City of Denver was engaged in the construction of these or other enterprises may properly be considered together with all other evidence as to existing facilities and ability of the city in determination of the issue of reasonable diligence.

Considering the Blue River project by itself: Denver's first plan of 1922 contemplated *1001 the appropriation of water from the south fork of Swan River, a tributary of the Blue River, by means of a tunnel which would take the water to Jefferson Creek, a tributary of Tarryal Creek, which in turn is a tributary of the South Platte River. That plan required seventy-six miles of collection flumes and tunnels along steep slopes and over difficult terrain to bring the water to the headgate of the main transmountain tunnel. There is no evidence of any actual construction work whatever on that proposed project. The upper portal of its proposed tunnel was many miles from the portal of that under subsequent plans. Its altitude was 10,322 feet as against an altitude of approximately 8,800 feet under subsequent plans. The length of its tunnel was approximately four and a half miles compared with that of approximately twenty-four miles under subsequent plans. It could collect water from less than half of the area available to supply the presently proposed tunnel. The 1923 plat of that project showed claim to appropriate 1200 second feet, while the 1927 plat shows claim for 1600 second feet, not by virtue of enlargement of the former claim, but as "a relocation of the project." No appropriation was ever awarded to it or claim filed for adjudication in its behalf, and any thought of its construction was abandoned upon the final adoption of a later plan. Plainly, at the time of the survey and of the filing of the plat of said first plan in 1923, there was no fixed and definite purpose to take it up and carry it through; there was no diligence in its construction, but an entire abandonment. The priority of a water right may not be dated back to the date of survey or filing of plat of a diversion proposal which has been abandoned in favor of another and very different plan. Holbrook Dist. v. Ft. Lyon Canal Co., 84 Colo. 174, 269 P. 574; Colorado Land & Water Co. v. Rocky Ford Co., 3 Colo.App. 545, 34 P. 580; State of Wyoming v. Colorado, 259 U.S. 419, 42 S.Ct. 552, 66 L.Ed. 999. Therefore no part of Denver's claim can be tied or dated back to its 1923 plat.

The next step in the attempted solution of the Blue River problem was taken sometime in 1926, when Engineer Bull was sent by Denver to study a more simple method of collecting and carrying its waters than appeared from the plan presented in Exhibit A. An extended survey in that year followed by office work resulted in preparation of Denver's Exhibit B, which was filed in the office of the state engineer on October 19, 1927. Denver contends that the priority of its Blue River project should be dated back at least to the date of such filing. The trial court denied that contention.

Two issues presented themselves to the trial court therein. (1) Was there in 1927 a fixed and definite purpose to take the plan shown by Exhibit B and carry it through to completion? (2) If so, was that plan prosecuted with due diligence? In order to support Denver's claim to the 1927 date, it was necessary to find both in the affirmative.

As to the first issue of fixed and definite purpose:

Our Colorado Constitution, article 16, section 6, provides that "priority of appropriation shall give the better right". Appropriation requires actual diversion and use. The doctrine of relation back is a legal fiction in derogation of the constitution for the benefit of claimants under larger and more difficult projects and should be strictly construed. Fruitland Irr. Co. v. Kruemling, 62 Colo. 160, 162 P. 161. It is not sufficient that there was an intent to divert from the Blue. In order to date back such intent must have been to divert a definite volume as evidenced by the capacity of the ditch and at a definite point evidenced by location of the headgate so that other appropriators could know the nature and extent of the claim.

If we assume that a filing under our map statute, chapter 90, sections 27-32, '35 C.S. A., constitutes notice to other appropriators as well as evidence in court, and that the provisions as to the time of filing are surplusage, still such maps are, as declared therein, only prima facie evidence of intent to make such construction and to utilize such rights as are shown in the map and statement. Was there any evidence in the *1002 record to overcome the prima facie evidence of the map? We think there was, both as to volume and as to fixed plan of diversion.

A. As to volume:

Denver's map and statement of 1927 showed a tunnel of 1600 second feet capacity and thereby if timely prima facie its intent to divert that maximum volume of water. But the testimony showed without contradiction that the tunnel as later planned and as now being constructed has capacity of only 788 second feet. Moreover, there was in evidence an agreement executed as of the 18th day of March, 1943, between Denver and the South Platte Water Users Association wherein Denver agreed in part as follows:

"1. The facilities which are the subject matter of this contract comprise all the right or rights of both parties hereto to use physical structures acquired or constructed on or after September 27, 1942, for the diversion or storage of waters of the Blue River, and the legal title to which structures stands or will stand in the name of either of the parties to this agreement, and also the right or rights (without regard to date of initiation) of the parties to divert or use such Blue River water, which rights of diversion shall be in proportion to the respective ownerships of the parties as defined in paragraph 2 hereof.

"2. Ownership of the facilities shall be proportional to the financial contributions of the parties to this agreement to the construction or creation of the facilities made on or after September 27, 1942, * * *.

"4. * * * In event either party shall prosecute such development, the other party shall have the right, if exercised within five years of the expenditure, to contribute not to exceed fifty per cent of any amount expended by the other party on account of the construction, or acquisition, of any unit of the facilities, or the facilities as a whole, at the choice of the electing party * * *."

Such agreement would be convincing evidence that Denver had no fixed intent to appropriate for its users even the full capacity of the 788 second-foot tunnel, but only half that capacity, and that any or all of the remaining capacity of the tunnel might be owned by other parties for use in the irrigation of farms far from Denver and far outside the original and declared intent of the appropriator.

B. As to the plan and point of diversion:

The trial court had before it in evidence the application of the City and County of Denver under date of December 6, 1935, wherein Denver petitioned the Federal Emergency Administration of Public Works for an allotment of $100,000. That application recited, inter alia, the need of the South Platte basin for additional water, the existence of the Blue River immediately west of the Continental Divide, so that a tunnel could be constructed to bring water therefrom, the two surveys already made of alternative means of diversion and the possibility of constructing such transmountain tunnel at a number of other locations and other elevations. It further recited the possibility that a thorough study would show the necessity for, or at least the advisability of, a compensating reservoir on the Western Slope, and particularly called attention to the Green Mountain Reservoir site. It further recited the many studies and available data "concerning the possibility of diverting Blue River water into the South Platte watershed"; requested further study of such proposed diversion and "that these studies and investigations include survey for both the upper site and lower site for the transmountain tunnel and also the consideration of four or five additional routes for the tunnel." Therein Denver asked that the proposed survey should include "(e) a comparison of the different possible routes for the transmountain tunnel, including a study of variations in possible method, such as pumping the water to a higher elevation so as to obtain the advantage of a shorter tunnel; (f) the relative costs of various routes of the transmountain tunnel and the various methods of constructing the same."

*1003 There was before the court also much evidence that in 1938, 1939 and 1941, there had been study by the Board of Water Commissioners of Denver and the United States Bureau of Reclamation as to the value, expense, and method of Blue River diversion; that numerous conferences were held with Bureau representatives and discussion had of different plans and methods of diversion, and additional surveys were made therefor; that the Bureau of Reclamation appropriated funds for such surveys and, on December 31, 1941, Denver agreed to share in the expense of surveys and appropriated $100,000 therefor; that an engineering board of review was set up in 1941, consisting of members from the Board of Water Commissioners of Denver, the South Platte Water Users Association, the Bureau of Reclamation and Colorado Water Conservation Board, to check the various possible tunnel sites and determine which route was best; that said board investigated at least three different methods and routes by which Blue River water might be diverted and carried to the South Platte, one of which was much the same as the route proposed by Denver's Exhibit B, and that under date of February 16, 1946, that board made its report to the President, Board of Water Commissioners, City and County of Denver, and others interested, finding that there were definite engineering, construction, operation and administration advantages in the Montezuma route, and recommending that a detailed project report of that route be prepared.

The plan shown by Denver's Exhibit B provided for three points of diversion: one on the Blue at the intake of the tunnel; one on Ten Mile Creek, with a ditch to carry the water therefrom to the Blue, thence to the intake, and one on Snake River, from which a branch tunnel would take the water to the main tunnel. Thereafter, the plan was changed from a straight to a dog-leg tunnel. At some later time the plan was again changed to provide for the building of a large reservoir at Dillon near the confluence of the Blue with the Ten Mile and the Snake, and with a new single point of diversion in the reservoir which captured waters more than a mile below the former proposed points of diversion. Apparently about the same time, the plan was changed again to reduce the size of the tunnel from a capacity of 1600 second feet to a capacity of 788 second feet, and the small portion of the tunnel now constructed is of that smaller capacity. During the entire period from 1927 to 1946, substantially all the work done and all the money spent by Denver in connection with its Blue River project was for investigation and exploratory work or work in connection with Eastern Slope reservoirs which were not dependent on any one plan for diversion or even on Blue River water. This and similar evidence before the trial court presented substantial support to the contention of protestants that Denver had no fixed and definite plan and no definite point of diversion prior to the report and recommendation of said board in 1946, and supported the decree of the trial court consistent therewith.

As to the second question, that of diligence:

In summary, the evidence showed that the Exhibit A plan of 1923 has been abandoned without any construction whatever; that following the filing of the Exhibit B plan in 1927, no evidence of actual excavation work in connection with its proposed tunnel appeared until 1942, some fifteen years later, when a cut was made and a small exploratory tunnel was driven about 400 feet at a place then intended to be the west portal to ascertain the condition of the ground. The proposed location of the portal has since been changed and a part of the excavation has caved in. No other work was performed on the ground until July 1946 when work at the east portal of the tunnel was started. Denver's Chief Engineer testified that "That was the first actual construction work." It had been driven 2850 feet out of a total distance of approximately twenty-four miles in the period from 1946 to the date of hearing. In addition to the tunnel, Denver's plan of diversion as last approved at the time of the trial included the large Dillon Reservoir on *1004 the Blue River at the intake, plat of which was filed in 1942 but no construction begun before 1946.

As satisfying the requirement of reasonable diligence, Denver showed that after the filing of the plat in 1927, the tunnel line was staked in 1931-2, and triangulation survey monuments installed for geological studies. These surveys brought about an unfavorable report on the straight tunnel as platted and a recommendation that a dog-leg tunnel be constructed by way of Montezuma. But the new line was not staked and geologized until sometime in 1943, 1944 and 1945. Over a period from 1928 to 1948, Denver's witnesses testified that survey was made and rights of way acquired for the Two Forks Reservoir, but that reservoir is to be located on the South Platte River and, as shown in the application for right of way, was planned for regulation of that river, storage of its flood waters and power development. It has no essential connection with direct use diversion from the Blue River; even its construction would not indicate any plan for Blue River diversion or give another appropriator any notice of such plan. Between 1928 and 1932 surveys were made for power lines to carry the electrical energy proposed to be generated by the project. In 1932, right of way was granted for the twenty-three mile tunnel, but for a period of ten years no step was taken toward its construction. It appears that throughout the period from 1936 to 1941 efforts were made by the City to induce the United States Bureau of Reclamation to build the project, but without success. There was no evidence of any effort by Denver to finance the project itself prior to the year 1946, but only of efforts to induce the United States to do so.

To support its contention that this work was sufficient to satisfy the requirements of reasonable diligence, Denver cites Taussig v. Moffat Tunnel Co., 106 Colo. 384, 106 P.2d 363, wherein it was held that surveys, preparation of maps, acquiring of rights of way and options and obtaining a contract for the carriage of water through the Moffat Tunnel, drilling of test holes, clearing of timber along proposed ditch lines and other similar work was sufficient to satisfy the requirement of reasonable diligence in construction of a ditch leading to the Moffat Tunnel. However, there the party seeking diversion of the water was a private company of apparently limited resources. The dating back was apparently for a period of less than five years, and the decision of this court affirmed the finding of the trial court, holding that there was due diligence; while here, we are asked to hold that such expenditures on the part of a great city, without shown limitation upon its financial capacity, spread out over a period of nearly twenty years would require us to reverse the decision of the trial court and say that such expenditures were evidence of reasonable diligence as a matter of law.

Kinney, in his great work on irrigation, says: "Probably the best definition of the word diligence was given by Lewis, C. J., in rendering the opinion in an early Nevada case, Ophir Silver Min. Co. v. Carpenter, 4 Nev. 534. It is there defined as `the steady application to business of any kind, constant effort to accomplish any undertaking.' `It is the doing of an act or series of acts with all possible expedition, with no delay except such as may be incident to the work itself.'" Kinney on Irrigation and Water Rights, Vol. 2, § 735.

Our statute authorizing conditional decrees requires that each claimant shall offer proof in support of his claim and "if it shall appear that any claimant * * * has prosecuted his claims of appropriation and the financing and construction of his enterprise with reasonable diligence", '35 C.S.A. c. 90, § 195, the court shall enter decree determining the priority of right.

It is undisputed that during a period of about twenty years, Denver had not even begun the actual construction of its project and had made no effort whatever as appears from the record towards financing it, but only a laudible but fruitless attempt after nine years of inaction to induce the United States Reclamation Service to finance it for the joint use of Denver and the South Platte Water Users Association. Meanwhile others have worked diligently and long to put a part of this water to actual use. The record before us does not show *1005 such conclusive evidence of "steady application" to the business of constructing the project or of such "constant effort to accomplish" it as to require us to hold that the trial court erred in refusal to date back Denver's appropriation, to the loss of such prior users. On the contrary, in order to sustain Denver's claim, we should have to establish as a law of Colorado that a great city or a great corporation, by the filing of a plat of a water diversion plan and the fitful continuance of surveys and exploratory operations, could paralyze all development in a river basin for a period of nineteen years without excavating a single shovel full of dirt in actual construction and without taking any step towards bond issue or other financing plan of its own for carrying out its purpose; that for nineteen years no farmer could build a ditch to develop his farm and no other city or industry could construct a project for use of water in that area without facing loss of their water when and if the city or corporation which filed the plat should actually construct its