MH-MMIC Water Rights

Class “A” stock shares receive water from the 13 c.f.s. (cubic feet per second) direct flow irrigation water right in the Mountain Meadow ditch.  The Company can usually divert “A” water during spring run-off, but the right will typically be superseded by senior water rights by mid-June. Water rights that are senior to the Mountain Meadow right add up to around 46 c.f.s, meaning that Cattle Creek needs to have almost 60 c.f.s of flow in order for the company to be able to divert the full 13 c.f.s.  Since it is a direct flow right, “A” water may not be stored in the reservoir for use later in the season.

Class “B” stock shares draw water from Spring Park Reservoir which has a capacity of ~1,700 acre-feet and a decree for 2,843 acre-feet of storage for irrigation use.  The reservoir can fill and re-fill from a 40 c.f.s water right in the Mountain Meadow ditch.  Since it is a storage right and one of the more junior rights on Cattle Creek, most of the time period during which the reservoir is filling occurs outside of the irrigation season when other more senior ditches are not diverting: in November before freeze-up, then starting again in early March. Since there is little flow in Cattle Creek in the off season, the critical period for filling the reservoir is during spring run-off (mid-April to mid-May) just before the other ditches turn on.

The Mountain Meadow ditch has a capacity of around 70 – 80 c.f.s.  During spring run-off when “A” shareholders are irrigating, if there is enough flow in Cattle Creek the ditch may carry water over and above their 13 c.f.s. class “A” water right.  This additional water, the Class “B” water right, is stored in Spring Park Reservoir for use later by “B” shareholders.  In the rare years when there is lots of snow in the upper watershed and the reservoir fills before Cattle Creek drops below 60 c.f.s , the Company can deliver the excess water to “B” shareholders while maintaining a full reservoir. This was the case in 2019 and 2023.  More typically, as other ditches on Missouri Heights begin diverting their water out of Cattle Creek in early May, the company must reduce its diversion or shut off altogether to allow the more senior rights to be fulfilled.  In this case the reservoir may not fill completely, and diversion of “A” shares may end earlier than “normal”.  For instance, in 2021, a year of very low snowpack, the spring run-off in Cattle Creek never got up to the 46 c.f.s necessary for the Company to begin to divert “A” water, and the reservoir, deprived of water from the spring flood, only filled to around 8.5’ vertical, which is slightly above where we usually end up after the irrigation season is over.  As a result, the Company delivered no water to shareholders in 2021.