delivered the opinion of the court:
In the year 1885 the plaintiff located upon cer-. tain lands in the vicinity of Newland creek near the city of Florence. He constructed ditches for the purpose of taking water from Newland creek to irrigate these lands. In 1899 defendant constructed a system of water works and to supply such system took the water of Newland creek. In 1903 this action was brought by the appellee in the district court of Fremont county to recover a judgment for damages alleged to have been suffered by- him on account of the taking of the water by appellant, it being contended that the appellant diminished the quantity of water in Newland creek to such an extent as to render it impossible for plaintiff to secure a sufficient quantity to irrigate his lands.
The issues were so framed that the measure of damages was conceded to be the difference between the value of the land previous to the taking of the water by the city and after the same had been taken.
Plaintiff testified as to the manner in which he had farmed and, somewhat meagerly, as to the quantity of water which he had received, and that the value of the land with such water was between seventy-five and one hundred dollars per acre.
The city had a number of witnesses sworn who testified as to their familiarity with Newland creek, and that at no time did it furnish a sufficient supply of water to irrigate the lands of plaintiff to such án extent as to make the cultivation thereof either practical or profitable. The principal issue in the case as tried was as to the quantity of this water and the duration of the supply. Plaintiff called as a witness Griffith Davis, who testified that in 1897 he saw a crop of corn on the place, and that crops could not be successfully raised in that neighborhood without irriga*512tion. Then in response to the following questions he testified:
Q. — “Have you been somewhat familiar with the lands along the various creeks in that neighborhood and their price and value for a number of years from your acquaintance with the people who own them and lands there?”
A. — “Oh, well, not particularly, no. To a certain extent, of course, I had my ideas, consulting at times with the people.”
Q. — “And you have known of ranches being sold here and there at times have you, and bought by different people?”
A. — “Not many ranches.”
Inquiry was then made of the -witness as to the market value of land such as the plaintiff’s. Defendant objected because he failed to show himself a competent witness. The objection was overruled and the witness was permitted to testify that the land was worth from seventy to eighty dollars per acre. There is nothing in the testimony of this witness to show that he had any knowledge of the value of lands of the character of plaintiff’s. There is nothing to show that he had any knowledge of the supply of water which plaintiff was able to obtain1 from Newland creek, and he should not have been permitted to testify as to the value of this land and water until he had shown himself possessed of sufficient knowledge to qualify him as a competent witness.
■ There was only one other witness whose testimony corroborated that of the plaintiff as to the value of the land, and it is extremely doubtful if he was competent to express an opinion upon the subject. In questions of value a witness must often be permitted to testify as to his opinion, but in order to make that opinion competent evidence, it must be shown that the witness was qualified to speak upon *513the subject. — Teerpenning v. Corn. Ex. Ins. Co., 43 N. Y. 279, and cases there cited.
Witness Barker, called on behalf of plaintiff, in his examination in chief, testified that for twenty-six years he had lived about two and one-half miles east of Newland creek, and was acquainted with the plaintiff’s ranch; that he saw a crop of corn growing on the place about eight years ago; that he saw a ditch in the neighborhood of the ranch, and that it came from Newland creek; that he saw it when it was dry, and when there was water in it; he thought he saw the plaintiff irrigating once. Upon cross-examination he testified as to his familiarity with Newland creek; that he could not go to Florence from his home without crossing it. He was asked the following question:
“Does Newland creek furnish water enough to he depended upon for irrigation purposes at that place where you cross and recross going to Florence ? ’ ’
The objection that this was not cross-examination was sustained.
He was then asked the following question:
“When you have crossed Newland creek, one time with another, during the irrigation season, yoii may state what its condition was as to waterflow. ’ ’
There was the same objection and the same ruling. This was prejudicial error. The very purpose for which this witness was called apparently was to prove that this land had been irrigated with water taken from Newland creek. The issue which was being tried was the value of this water right. The value of the water right would depend largely upon the question as to whether or not the supply was permanent or whether it was temporary, and water could only be obtained at irregular intervals. It is contended by plaintiff that questions which were *514asked the witness did not relate to any matter concerning which, he testified in chief. As we have seen, - this contention is nnfonnded for the reason that it related to the very 'matter concerning which he did testify.
Plaintiff also contends that the matter of cross-examination of a witness rests in the discretion of the court, and the ease shonld not be reversed except where this discretion has been grossly abased; that if defendant had desired to prove this matter, it coaid have made the witness its own for that parpóse. This is not the rale, as we anderstand it. At least two cases have been reversed by this coart becaase of a refasal of the trial coart to permit a safficient cross-examination of witnesses.— Patrick v. Crowe, 15 Colo. 543; Lothrop v. Roberts, 16 Colo. 250.
A qaestion which is very similar in principle to the one here involved arose in the case of Resurrection Gold Min. Co. v. Fortune Gold Min. Co., 129 Fed. 668, in which Sanborn, J., speaking for the circait coart of appeals, said:
“They say that permission to answer this qaestion was discretionary with the coart below, and that its refasal was no abase of discretion; that the answer to the qaestion woald have established an affirmative defense; and that the refasal to permit the introdaction of the answer was not prejndicial to the defendant, becaase it might have made the owner of this property its own witness and then have asked him the same qaestion; and that in any event the expected testimony was only cnmnlative. Bat a fair' and fall cross-examination of a witness apon the.snbjects of his examination in chief is the absolate right, and not the mere privilege, of the party against whom he is called, and a denial of this right is a prejndicial and fatal error. It is only after the right has been snbstantially and fairly exercised that the allowance *515of cross-examination becomes discretionary with the trial court.”
To sustain this position the learned judge cites authorities from the United States supreme court from Michigan-, Ohio, Massachusetts, California and South Dakota.
Because the court erred in the two particulars herein indicated and the errors were prejudicial to the defendant’s rights, the judgment of the district court must be reversed.
We do not pass upon the other questions raised by appellant, for the reason that they present no matters which will necessarily be involved in another trial of this action. Reversed.
Chief Justice Steele and Mr. Justice Goddard concur.