International Joint Commission invites public comment on “Report on High Water Levels in the Rainy River Watershed in 2014”
Members of the public and relevant agencies and organizations have 90 days to provide their input to the International Joint Commission (IJC) on the findings, recommendations and issues contained in a new report on 2014 high water levels in the Rainy River watershed.
The report was prepared by the Water Levels Committee of the International Rainy-Lake of the Woods Watershed Board (IRLWWB) at the request of the IJC. It provides a review of the conditions that led to high water in the Rainy River watershed in 2014 and responds to a number of questions posed by the IJC regarding the management of water quantity in the watershed.
Interested parties can comment on the report online or during one or more public meetings that will be hosted by the IJC in conjunction with the Board the week of August 10, 2015.
The public comment period closes on August 31, 2015.
The IJC will consider the report’s key findings and recommendations, as well as feedback from the public and relevant agencies and organizations, before determining its best course of action.
In June and July of 2014, the Namakan Chain of Lakes and Rainy Lake reached water levels higher than they had experienced in several decades.
Out flows from the dams at the outlets of these lakes are under the authority of the IJC, under the Rainy Lake Convention of 1938. The IJC-appointed IRLWWB established the Water Levels Committee (WLC) to monitor dam operations to comply with the IJC’s Rule Curves, which were established to manage the flows and levels in the watershed.
Read the IRLWWB’s complete report.
For further information, please contact:
In June and July of 2014, the Namakan Chain of Lakes and Rainy Lake reached levels higher than experienced in several decades. Flows out of the dams at the outlets of these lakes are under the authority of the International Joint Commission (IJC). The IJC-appointed International Rainy-Lake of the Woods Watershed Board (IRLWWB) has a committee, known as the Water Levels Committee (WLC), which is responsible for monitoring the operation of the dams for compliance with the IJC’s regulatory regime (known as Rule Curves). This report provides a review of the conditions that led to high water and answers a number of questions put for-ward by the IJC with respect to the high water event and management of water quantity in the Rainy River watershed.
The following points highlight the most significant details of the high water event:
- As a very substantial snowpack melted across the watershed in April, tributary flows rose above normal. The snowpack was nearly completely gone by early May, and inflow to most tributaries to the Namakan Chain of Lakes and Rainy Lake had nearly stabilized by mid-May. Significant rainfall in mid-May kept flows in the watershed above normal, but not exceptionally high. Record-high rainfall in the month of June brought inflow to extremely high levels across the watershed throughout June and into July.
- The extremely high inflow in June exceeded the capacity of the outlets to pass water, resulting in an un-controlled rise in the water levels of Rainy Lake and the Namakan Chain of Lakes.
- H2O Power LP and Boise Paper are the companies that own dams at the outlets of Rainy Lake and Namakan Lake and operate them under the direction of the IJC. The companies increased flow out of both lakes quickly in late April and early May. Namakan Lake was fully opened by May 16 to maximize outflow, while greater than 95% of the outflow capacity was released from Rainy Lake from May 20 until all gates at the dam were opened on June 6.
- The Namakan Lake dams remained fully opened from May 16 until July 20. Namakan Lake peaked at the third highest level since IJC regulation began in 1949. The lake remained above the Emergency Conditions level for forty-four days.
- The Rainy Lake dam remained fully opened from June 6 to August 8. Rainy Lake peaked at the second highest level since IJC regulation began in 1949 and remained above the Emergency Conditions level for seventy-two days.
- The level of the Rainy River, driven by extremely high local flows and maximum flow from the Rainy Lake dam, reached a new record stage in June, exceeding the previous record by nearly 30 cm (1 ft).
- Damage from high water was extensive across the watershed, including shoreline erosion and tree loss, dock and boathouse damage, and damage to buildings and other infrastructure. In addition, there were reports of reduced business at tourist outfitters and the considerable costs of time and resources devoted to the construction, maintenance and removal of flood defences. States of Emergency were declared in locations in both countries.
The highlights of the findings of the WLC’s review of the high water event are as follows:
- Fundamentally, high water occurred because the supply of water resulting from the June rainfall was far in excess of maximum outflow from the fully opened dams at Namakan and Rainy Lakes for several weeks.
- The WLC directed the companies to target the lower end of the Rule Curve ranges for these lakes in early April in order to create additional storage room for the melting of the substantial snow pack. This action did not influence the peak levels in the summer, as the companies returned to targeting the middle of the Rule Curve bands once the freshet was underway.
- Targeting much lower lake levels in mid-May for both lakes would have resulted in a very small reduction in the peak level at Rainy Lake, and almost no benefit at Namakan Lake. However, the extreme June rainfall was not forecast in early May and flows had been stabilizing by that point. As such there was no clear indication that lower targets were necessary. By mid-May, with outflow from the lakes at or near maximum, there were no additional steps that could have been taken to avoid the high water to come in June and July.
- The flow changes made at the outlets of the lakes by the dam owners were timely, prudent, and in compliance with the IJC’s regulations.
- Computer simulation modelling indicates that a 25 % reduction in the amount of precipitation between April and June would likely have allowed the levels of Namakan Lake and Rainy Lake to be maintained be-low Emergency Conditions levels.
- Simulations were completed to investigate the effect that operating under the current Rule Curves (established in 2000) had in comparison to operating under the previous Rule Curves (from 1970). The 2000 Rule Curves have a higher end-of-winter level at Namakan Lake and earlier refill of Namakan Lake in the spring. The simulation results indicate that following the 1970 Rule Curve in 2014 would have resulted in a slightly lower peak on Rainy Lake and would have had virtually no effect on the peak at Namakan Lake. This was anticipated when the review of the 1970 Rule Curves took place in the 1990s, and was considered an acceptable outcome when balanced against the benefits the Rule Curve changes were thought likely to pro-vide.
- The WLC is not aware of any changes to the landscape or structures at the outlets of these lakes since the original IJC order that could have reduced the outflow capacity at the Fort Frances/International Falls dam or the outlets of Namakan Lake.
- The peak levels reached in the Namakan Chain of Lakes and at Rainy Lake were much lower than in the record year of 1950. The lakes in 2014 also remained in Emergency Conditions for a much shorter period than in 1950. There is no regulation of the dams at the outlets of these lakes that will prevent a return to the levels experienced in 1950, or higher, if sufficiently extreme inflow develops in the future. The IJC, through the IRLWWB and WLC, should work with local governments, First Nations, and other community organizations to ensure that it is widely understood that the watershed is vulnerable to high water events and that regulations on shoreline building reflect this fact.
- The forthcoming review of the 2000 Rule Curves should give weight to avoiding conditions that would in-crease the likelihood of Emergency Conditions due to high water.
- The WLC recommends that the IJC review the role and responsibilities of the WLC during Emergency Conditions, and that it also consider the development of a protocol for communications during emergency events between the IJC, the IRLWWB, WLC, and local First Nations, tribes, and governments.
Charts excerpted from the Report