CFR > Title 25 - Indians > CHAPTER I—BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR > SUBCHAPTER H—LAND AND WATER (parts 150 to 183) > PART 171—IRRIGATION OPERATION AND MAINTENANCE > SUBPART G—Non-Assessment Status (§171.700 to §171.720) > 171.720—For what period does an Annual Assessment Waiver apply?