Hidden Lake Water Balance, algae bloom, exfiltration
Overview description: We submitted a request that the Yukon Water Board hold a public hearing of based on evidence we had collected on the algae bloom on Hidden Lake. At that time, IWL argued that the nutrients levels were not a result of their operations but were, in large, part due to background levels of nitrogen and phosphorus in the creek system. The Water Board hearing, at that time, required monitoring levels be maintained and recommended that the YTG and IWL work in collaboration to treat the effluent from the fish farm. We believe the evidence shows that water quality issues persist due to effluent from Icy Waters Ltd. This intervention represents an opportunity for the Water Board to set in place a course actions that will led to an improvement in the water quality of Porter Creek and Hidden Lake for the benefit of residents living adjacent to the water course and for other users of the waters. We also believe that the 2003 Water Board decision permitting IWL to release .12 mg/l of phosphorus above background levels has continue to result in the downstream algal blooms and the related rise in water levels of Hidden Lake. Community members have reported that this has had a negative impact on the perceived aesthetic and recreational values associated with the Porter Creek water system.
Overview description: We submitted a request that the Yukon Water Board hold a public hearing of based on evidence we had collected on the algae bloom on Hidden Lake. At that time, IWL argued that the nutrients levels were not a result of their operations but were, in large, part due to background levels of nitrogen and phosphorus in the creek system. The Water Board hearing, at that time, required monitoring levels be maintained and recommended that the YTG and IWL work in collaboration to treat the effluent from the fish farm. We believe the evidence shows that water quality issues persist due to effluent from Icy Waters Ltd. This intervention represents an opportunity for the Water Board to set in place a course actions that will led to an improvement in the water quality of Porter Creek and Hidden Lake for the benefit of residents living adjacent to the water course and for other users of the waters. We also believe that the 2003 Water Board decision permitting IWL to release .12 mg/l of phosphorus above background levels has continue to result in the downstream algal blooms and the related rise in water levels of Hidden Lake. Community members have reported that this has had a negative impact on the perceived aesthetic and recreational values associated with the Porter Creek water system.
The following four diagrams were included with the 2003 intervention showing the growth of algae on Hidden Lake. The fifth diagram, an aerial image shows the extent of the bloom in 2006 and the sixth photo shows the extent of the flooding and dead trees adjacent of homes. These images demonstrates the persistence of water quality issues in Porter Creek and Hidden Lake. |
The lake level increase has killed all the trees adjacent to lake below water level. ES classes also conducted dendrochronology studies on six of these trees. They were an average of 130 to 140 years old. This indicates that the lake has not risen to this level for the past 130 – 140 years. Hidden lake exfiltrates and the rise in the lake is due to the substrate of the lake coated with layers of algae resulting from the periodic blooms. The rise in the lake coincides with the beginning of IWL release of effluent. The age of the trees shows that this lake level event has not happened over the past 130 to 140 years. If the concentrations of phosphates in Porter Creek were dependent of background level, and had not been impacted by IWL, we could have expected lake levels to have raised in the past. The tree ages show this is an unlikely event. This indicates two things; that the background nutrient levels had not resulted in raised lake levels, but, the nitrates and phosphates added to the system by IWL to the system have resulted in the lake flooding.
Duration of study and numbers involved. Studies on Porter Creek and Hidden Lake began in 1991 and are ongoing through 2013. The studies have involved to Porter Creek Community Association and people who live around Versluice Meadows.
Contact person and more detailed information Bob Sharp and the Porter Creek Community Assn have been the contacts for these two interventions. The reasons for decision were given for the first but not the second intervention.
Duration of study and numbers involved. Studies on Porter Creek and Hidden Lake began in 1991 and are ongoing through 2013. The studies have involved to Porter Creek Community Association and people who live around Versluice Meadows.
Contact person and more detailed information Bob Sharp and the Porter Creek Community Assn have been the contacts for these two interventions. The reasons for decision were given for the first but not the second intervention.