By Josh Margolis
GLASGOW, Mont. (NMB) – With the failure of a drop structure on the St. Mary Canal and Conveyance Works System back on May 17th halting the flow of water from the St. Mary to the Milk River, Montana Fish, Wildlife and Parks says local reservoirs and fisheries will soon begin to see negative impacts.
FWP says Fresno Reservoir is currently nine feet below full pool and is projected to be 24 feet below full pool by August 15th after a significant draw-down due to increased water demands, which could be detrimental to the fish community.
Nelson Reservoir is currently two feet below full pool, and is expected to drop five feet by mid-August, which should not have any impact on the fish community.
Fresno and Nelson Reservoirs’ primary function is water storage for irrigation and flood control.
Impacts to fisheries of the Milk River itself will be determined by how long the river sections are dry or see limited flow. The river above Fresno could see significant impacts as Canadian irrigators will be utilizing their Milk River natural flow water right. Overall, Milk River impacts will be mitigated if there are good late summer and fall rain and if the repairs to the St. Mary Canal water structures are completed by fall.
