This is a continuing obligation. See Washington County Irrigation Dist. v. Talboy, 55 Idaho 382, 390, 43 P.2d 943, 946 (1935); Glavin v. Salmon River Canal Co., 44 Idaho 583, 589-90, 258 P. 532, 534 (1927). Partial forfeiture makes possible allocation of water consistent with beneficial use concepts.
However, in an appropriation without a diversion, the right acquired is not to the stream flow as was the case under the riparian system, but to the use of a specific amount of water which is the subject of the right. That amount must be a reasonable and efficient use of the water. Glavin v. Salmon River Canal Co., Ltd., 44 Idaho 583, 258 P. 532 (1927); Union Grain Elevator Co. v. McCammon Ditch Co., 41 Idaho 216, 240 P. 443 (1925). With regard to the Malad Canyon appropriation, I.C. ยง 67-4312 provides:
" Respondents rely on the case of Glavin v. Salmon River Canal Co., 44 Idaho 583, 258 P. 532, in support of the contention "that the minute appellant was unable to use the water (stored) in any year, it then became public unappropriated water," and that respondents might thereupon use it without let or hindrance and without liability therefor to appellant. The Glavin case is not controlling here.