Dam rebuilt to help kokanee
August 31, 1991
Incubating kokanee won’t be left high and dry in Mission Creek this fall.
Uneven water flow in the creek is a major problem during the low flows of summer and fall. The answer is a supply of water from Loch Long, located 57 km northeast of Kelowna in the Mission Creek watershed.
It was identified by Environment Ministry staff as having the best unused water storage potential in the Greystokes. It even had an old irrigation district dam built in the 1930s.
By the 1970s, other sources of water had been developed and the dam was sold to the ministry. By 1990, the dam was in such disrepair that it was breached for safety reasons.
The rebuilt dam will hold back water during spring runoff and then release it into Mission Creek, the Okanagan’s most important spawning stream, during the summer and fall. Kokanee spawn in mid-September.
The suggestion to rebuild the Loch Long dam to provide water for the kokanee spawning beds coincided with Finning Ltd. approaching the ministry with an offer of assistance for environmentally-friendly projects.
Finning, the B.C. dealer for Caterpillar Equipment, provided the use of an excavator, bulldozer and all-terrain dump truck, plus $5,000 cash, for a total contribution of $35,000.
The Habitat Conservation Fund, funded primarily by a licence surcharge paid by anglers, hunters, trappers and guides, provided another $46,000.
Finning operators in Vernon and Kamloops also got private sector donations of a grader and operator from Fletcher Challenge, and fuel tanks from Schweb Contracting and Balcaen Consolidated Contractors Ltd.
Work on the dam began in early August with upgrading of an existing forestry road and site preparation.
Dry mix concrete was hauled from Kelowna and water added on-site to maintain maximum quality and minimize loads on forestry roads. A new concrete spillway was built and an old pipe filled with concrete to seal it off.
The new two-metre-high concrete structure, completed this week, will increase the maximum depth of Loch Long to four metres. A 50-cm pipe through the concrete and a sliding gate will control normal outflow.
The rest of the 200-metre long dam is earth fill, rising one metre above the concrete structure. A saddle dam on the north side of the lake will supplement the main dam.
If Loch Long exceeds its maximum level, water will spill over the concrete structure and go directly into the channel. Water levels will be monitored and controlled jointly by the ministry’s fisheries section and Black Mountain Irrigation District.