The right of appropriation for irrigation purposes is limited to the waters of natural streams of the state, and does not extend to waters in artificial drainage ditches. Drainage Dist. No. 1 v. Suburban Irr. Dist., 139 Neb. 460, 298 N.W. 131 (1941).

Senior appropriator is entitled to water as against an upstream junior appropriator, as long as water in usable quantities can be delivered to senior appropriator. State ex rel. Cary v. Cochran, 138 Neb. 163, 292 N.W. 239 (1940).

It is the duty of the state to see that the waters of its streams used for irrigation purposes will not be wasted and that prior appropriators shall be protected as against subsequent appropriators. State ex rel. Sorensen v. Mitchell Irr. Dist., 129 Neb. 586, 262 N.W. 543 (1935).

While Nebraska was originally a riparian doctrine state, legislation was enacted adopting the principle of prior appropriation. Nebraska v. Wyoming, 325 U.S. 589 (1945).

United States cannot claim assignment to it of excess waters under an appropriation, as excess would inure to benefit of other appropriators prior in time to United States. United States v. Tilley, 124 F.2d 850 (8th Cir. 1941).