In 1878 William B. Morris Constructed an irrigation canal by means of which water was diverted from Boise River. At about that time he sold, and thereafter his heir and devisee conveyed, to the predecessor in interest of respondent’s intestate a section of land and a free and perpetual water right therefor from the canal.
In 1889 the canal was greatly enlarged and extended by the successors in interest of Morris for the purpose of eon*193veying water to other lands than those intended to be irrigated from it at the time the water right in question was disposed of as above stated. The enlargement and extension were not made for the benefit, nor with the consent, of respondent’s intestate nor of his predecessor in interest.
Prior to the enlargement and extension the canal was about 16 feet wide on the top, 10 feet wide on the bottom, 4 feet in perpendicular depth and 7 miles long. Its length was considerably augmented by two sloughs, into which it emptied water and from which it was taken, by means of ditches or laterals, and applied to the irrigation of lands in that vicinity.
The canal as originally constructed and the irrigation system of which it was a part were primitive in character, but inexpensive to the water users and answered their purpose. Since 1888 the property has been, by appellant and its predecessors in interest, developed into a comprehensive irrigation system composed of many miles of main canals and laterals, efficient in the distribution of water for irrigation purposes, and proportionately expensive in management, upkeep and improvement.
Appellant is an irrigation district. It obtained title to the system by deed dated December 4, 1905, and has had actual possession, management and control thereof continuously since January 1, 1906. Respondent’s intestate, at the time of his death, owned 320 acres of land, and his water right therefor, derived as above stated, consisted of 250 miner’s inches of water supplied from appellant’s irrigation system. The land is not within the district and respondent has not, nor had her intestate, any voice in its government.
Appellant required respondent’s intestate to pay $1 per miner’s inch of water to be delivered to .his land during 1912 on the theory that such sum was his proportionate part of the expense of distribution of water by it, to lands within the district as well as to others, and his proportionate part of the expense of maintenance and upkeep of the entire system, including the cost of government of the district. In like manner, and upon like theory, there was exacted *194from and paid by the administrator of the intestate’s estate, $1.10 per miner’s inch of water to be delivered during each of the years 1913 and 1914. These sums were required to be paid in advance of delivery of water each year, and were paid under protest and because refusal to pay would have resulted in the water being withheld and in the destruction of crops growing on the land.
Eespondent alleged in her complaint that the sums so collected should not have exceeded twenty-five cents per miner’s inch of water delivered each year. The trial court found that each of the charges above mentioned was paid involuntarily, under coercion and compulsion; that the total cost of delivering water to the land did not exceed fifty cents per miner’s inch per year, and entered judgment in respondent’s favor for amounts paid in excess of that.
A kindred question to the one now before us was under consideration by this court in Nampa & Meridian Irr. Dist. v. Gess, 17 Ida. 552, 106 Pac. 993, involving a water right of which this one is a part. It was Contended no charge should be made against the owner of the water right by way of contribution to the cost of maintenance of the canal and distribution of water therefrom. This court held the language of the deed, whereby was granted the free and perpetual use of water for the purpose of irrigating the land, did not mean the canal should be kept up and maintained by the grantors and their assigns and the water be delivered free of maintenance charge and actual cost of delivery, but the question was not presented, nor was it decided, as to what should be taken into consideration in determining the proportion of maintenance and delivery cost which should be paid by the owner of that water right and his successors.
Counsel for appellant contends that respondent, the district and others are’ joint owners of the canal system; that if respondent, or her intestate, was dissatisfied with the amount exacted for the maintenance and upkeep of the system, relief might have been had by appropriate action, and that the payments were voluntarily made and, even if unjust, no part thereof can be recovered.
*195Appellant was in possession of the irrigation system, had exclusive control of the headgates, which were kept locked, and adopted and enforced rules and regulations whereby the distribution of water to the lands of those entitled to it was made. While, generally, the existence of a remedy at law will defeat a claim that the payment of an unjust demand was involuntarily made, in order to do so such remedy must be reasonably adequate. In an arid country, such as is the southern part of Idaho, the extreme and immediate necessity for water for crops during the irrigation season rendered the remedies provided by law, which were available to respondent and her intestate, inadequate, and justifies the trial court’s finding that the payments were made involuntarily and under coercion and compulsion. (Rowland v. Watson, 4 Cal. App. 476, 88 Pac. 495; Siverson v. Clanton, 88 Or. 261, 170 Pac. 933, 171 Pac. 1051; De Graff v. Board of County Commas., 46 Minn. 319, 48 N. W. 1135; Panton v. Duluth Gas. & Water Co., 50 Minn. 175, 36 Am. St. 635, 52 N. W. 527; Joannin v. Ogilvie, 49 Minn. 564, 32 Am. St. 581, 52 N. W. 217, 16 L. R. A. 376; Finch v. J. M. Cox Co., 19 Ga. App. 256, 91 S. E. 281; Westlake & Button v. City of St. Louis, 77 Mo. 47, 46 Am. Rep. 4.)
Appellant’s contention that respondent’s intestate was a joint owner in the canal system is sound to only a limited extent; that ownership is confined to the interest he had by virtue of his water right in the Morris canal. When appellant’s predecessors purchased that Canal they took it subject to the rights of respondent’s intestate and burdened with its obligation to him and his successors. They could and did enlarge and extend it for the benefit of themselves and others whose lands were to be by that means supplied with water, but they could not, and did not, thereby diminish his rights or increase his burdens. By enlarging and extending the canal appellant’s predecessor neither conferred upon respondent’s intestate an interest in the enlarged system nor did it'deprive him of his interest in the property as it existed before it was enlarged.
*196While, as a matter of fact, the Morris canal has been so merged in the enlarged system that it may no longer be distinguished from other component parts thereof, in contemplation of law it still exists as a separate entity and limits respondent’s liability for contribution to the cost of maintenance of the irrigation system and the distribution of water therefrom. (Nampa & Meridian Irr. Dist. v. Manville, 31 Ida. 397, 173 Pac. 113.) That contribution, for 1912, 1913 and 1914, should not be in excess of the amount it would have cost to deliver 250 miner’s inches of water throu'gii the Morris canal to the land in question during those years had it not been enlarged or extended beyond the limits and capacity contemplated at the time the predecessor in interest of respondent’s intestate purchased the water right.
There is no evidence tending to show the amount expended by appellant in the upkeep and maintenance of that portion of the system of which the Morris canal became a part, nor of the expense of distribution of water therefrom, nor does it appear that any separate account was kept of these items, nor was any effort made to prove what portion of that expense would, in reasonable probability, have been necessary in order to deliver water through the Morris canal to the land in question had it .not been enlarged and extended, .
The payments having been exacted on an erroneous theory and made when no service had been performed by appellant for the benefit of respondent’s intestate or of his estate, and respondent having shown the collection was made under circumstances which amounted to placing . the payers under duress, the burden of evidence, as distinguished from burden of proof (16 Cyc., pp. 926 and 932), was on appellant to show it did not collect more than thereafter became due to it. In other words, the amount it .expended which was justly chargeable to intestate’s, estate was an offset against respondent’s claim for money paid under duress.
As above indicated, the evidence does not show what expenditures were made by appellant, to the repayment of which respondent should contribute. It is admitted in the complaint that twenty-five cents per miner’s inch of water *197each year is a reasonable charge to be allowed to appellant, and respondent has not appeáled from the allowance of double that amount. If error was committed by allowing more than the pleadings and evidence justified, no injury has thereby resulted to appellant.
The judgment is affirmed, with costs to respondent.
Bice, J., concurs.