Voyageurs National Park was established in 1975 to preserve the scenery and remote system of interconnected waterways along a portion of the US-Canada border. The complexity of the waterways increased with the installation of dams in the early 1900s. Subsequently, the International Joint Commission set rules governing dam operation (rule curves) for this system of lakes, with the most recent adjustment in 2018. The U.S. Geological Survey and National Park Service collaborated on several studies to evaluate the rule curves and how they are related to a wide range of hydrologic, environmental, and cultural resources observed in park lakes.
Within Voyageurs National Park, along the Minnesota-Canadian border, water levels are controlled by a series of dams to support a variety of uses. Previous research has indicated a relation between these artificially maintained water levels and water-quality and aquatic biological effects in these lakes (Christensen et al. 2011, 2013; Cole 1979, 1982; Kallemeyn et al. 1993). Relations were documented between water levels and chlorophyll-a concentrations in the most eutrophic lakes in the system (Christensen et al. 2011) and a link was established between water-level fluctuations and mercury concentrations in fish (Wiener et al. 2006, 2013) due to the drying and rewetting of wetlands and other near-shore areas, which may release methylmercury into the water when inundated.
A better understanding of water-level effects on water quality and biology was needed. To address this need, the U.S. Geological Survey, National Park Service, and other agencies cooperated in a series of studies to assess the importance of water-level fluctuation and other factors affecting water-quality and mercury concentrations of fish in lakes of Voyageurs National Park. The purpose of this paper is to summarize the findings of these studies where international water-level regulation was a major factor.
Our research has shown a decrease in chlorophyll-a concentration and an increase in Secchi depth in two of the most eutrophic water bodies in the park. However, significant improvements were not seen for total phosphorus. A follow-up study suggested a possible link between frequent recirculation and internal recycling of phosphorus. Additional studies evaluated trophic state, flow direction, fish mercury concentrations, cyanobacterial harmful algal blooms, and cultural resources. These collaborative studies provided useful information for a review of previous rule curves leading to the 2018 Supplementary Order issued by the International Joint Commission, which prescribes a new method of regulating water levels of international border lakes.
Below are data or web applications associated with this project.
Phytoplankton enumeration and identification from a recurring algal bloom location in Sullivan Bay, Kabetogama Lake, northern Minnesota, 2016
Below are publications associated with this project.
A history of trade routes and water-level regulation on waterways in Voyageurs National Park, Minnesota, USA
Voyageurs National Park: Water-level regulation and effects on water quality and aquatic biology
Lake levels and water quality in comparison to fish mercury body burdens, Voyageurs National Park, Minnesota, 2013–15
Discharge and nutrient transport between lakes in a hydrologically complex area of Voyageurs National Park, Minnesota, 2010-2012
Trophic state in Voyageurs National Park lakes before and after implementation of a revised water-level management plan
Evaluation of internal loading and water level changes: implications for phosphorus, algal production, and nuisance blooms in Kabetogama Lake, Voyageurs National Park, Minnesota
Relation of nutrient concentrations, nutrient loading, and algal production to changes in water levels in Kabetogama Lake, Voyageurs National Park, northern Minnesota, 2008-09
Effects of changes in reservoir operations on water quality and trophic state indicators in Voyageurs National Park, northern Minnesota, 2001-03
- Overview
Voyageurs National Park was established in 1975 to preserve the scenery and remote system of interconnected waterways along a portion of the US-Canada border. The complexity of the waterways increased with the installation of dams in the early 1900s. Subsequently, the International Joint Commission set rules governing dam operation (rule curves) for this system of lakes, with the most recent adjustment in 2018. The U.S. Geological Survey and National Park Service collaborated on several studies to evaluate the rule curves and how they are related to a wide range of hydrologic, environmental, and cultural resources observed in park lakes.
Within Voyageurs National Park, along the Minnesota-Canadian border, water levels are controlled by a series of dams to support a variety of uses. Previous research has indicated a relation between these artificially maintained water levels and water-quality and aquatic biological effects in these lakes (Christensen et al. 2011, 2013; Cole 1979, 1982; Kallemeyn et al. 1993). Relations were documented between water levels and chlorophyll-a concentrations in the most eutrophic lakes in the system (Christensen et al. 2011) and a link was established between water-level fluctuations and mercury concentrations in fish (Wiener et al. 2006, 2013) due to the drying and rewetting of wetlands and other near-shore areas, which may release methylmercury into the water when inundated.
A better understanding of water-level effects on water quality and biology was needed. To address this need, the U.S. Geological Survey, National Park Service, and other agencies cooperated in a series of studies to assess the importance of water-level fluctuation and other factors affecting water-quality and mercury concentrations of fish in lakes of Voyageurs National Park. The purpose of this paper is to summarize the findings of these studies where international water-level regulation was a major factor.
Our research has shown a decrease in chlorophyll-a concentration and an increase in Secchi depth in two of the most eutrophic water bodies in the park. However, significant improvements were not seen for total phosphorus. A follow-up study suggested a possible link between frequent recirculation and internal recycling of phosphorus. Additional studies evaluated trophic state, flow direction, fish mercury concentrations, cyanobacterial harmful algal blooms, and cultural resources. These collaborative studies provided useful information for a review of previous rule curves leading to the 2018 Supplementary Order issued by the International Joint Commission, which prescribes a new method of regulating water levels of international border lakes.
- Data
Below are data or web applications associated with this project.
Phytoplankton enumeration and identification from a recurring algal bloom location in Sullivan Bay, Kabetogama Lake, northern Minnesota, 2016
This data release provides phytoplankton identification, phytoplankton enumeration, chlorophyll concentration, phaeophytin concentration, phycocyanin data, and nutrient quality assurance data from three recurring algal bloom sites in Kabetogama Lake, Voyaguers National Park, Minnesota in 2016 and 2017. The goal of this research is to better understand the drivers of algal bloom toxicity in the lar - Publications
Below are publications associated with this project.
A history of trade routes and water-level regulation on waterways in Voyageurs National Park, Minnesota, USA
Unlike most national parks, main access to Voyageurs National Park is by boat. This remote system of interconnected waterways along the USA-Canada border was an important transportation route for thousands of years of American Indian occupation, leading up to and including the trade route of the voyageurs, or French-Canadian fur traders from around 1680 to 1870. The Ojibwe people collaborated withVoyageurs National Park: Water-level regulation and effects on water quality and aquatic biology
Following dam installations in the remote Rainy Lake Basin during the early 1900s, water-level fluctuations were considered extreme (1914–1949) compared to more natural conditions. In 1949, the International Joint Commission (IJC), which sets rules governing dam operation on waters shared by the United States and Canada, established the first rule curves to regulate water levels on these waterbodiLake levels and water quality in comparison to fish mercury body burdens, Voyageurs National Park, Minnesota, 2013–15
Within Voyageurs National Park in Minnesota, lake levels are controlled by a series of dams to support a variety of uses. Previous research indicates a link between these artificially maintained water levels, referred to as rule curves, and mercury concentrations in fish owing to the drying and rewetting of wetlands and other nearshore areas, which may release methylmercury into the water when inuDischarge and nutrient transport between lakes in a hydrologically complex area of Voyageurs National Park, Minnesota, 2010-2012
An acoustic Doppler velocity meter (ADVM) was deployed in the narrows between Namakan and Kabetogama Lakes in Voyageurs National Park, Minnesota, from November 3, 2010, through October 3, 2012. The ADVM can account for wind, seiche, and changing flow direction in hydrologically complex areas. The objectives were to (1) estimate discharge and document the direction of water flow, (2) assess whetherTrophic state in Voyageurs National Park lakes before and after implementation of a revised water-level management plan
We compiled Secchi depth, total phosphorus, and chlorophyll a (Chla) data from Voyageurs National Park lakes and compared datasets before and after a new water-level management plan was implemented in January 2000. Average Secchi depth transparency improved (from 1.9 to 2.1 m, p = 0.020) between 1977-1999 and 2000-2011 in Kabetogama Lake for August samples only and remained unchanged in Rainy, NamEvaluation of internal loading and water level changes: implications for phosphorus, algal production, and nuisance blooms in Kabetogama Lake, Voyageurs National Park, Minnesota
Hydrologic manipulations have the potential to exacerbate or remediate eutrophication in productive reservoirs. Dam operations at Kabetogama Lake, Minnesota, were modified in 2000 to restore a more natural water regime and improve water quality. The US Geological Survey and National Park Service evaluated nutrient, algae, and nuisance bloom data in relation to changes in Kabetogama Lake water leveRelation of nutrient concentrations, nutrient loading, and algal production to changes in water levels in Kabetogama Lake, Voyageurs National Park, northern Minnesota, 2008-09
Nutrient enrichment has led to excessive algal growth in Kabetogama Lake, Voyageurs National Park, northern Minnesota. Water- and sediment-quality data were collected during 2008-09 to assess internal and external nutrient loading. Data collection was focused in Kabetogama Lake and its inflows, the area of greatest concern for eutrophication among the lakes of Voyageurs National Park. Nutrient andEffects of changes in reservoir operations on water quality and trophic state indicators in Voyageurs National Park, northern Minnesota, 2001-03
Implementation of an order by the International Joint Commission in January 2000 has changed operating procedures for dams that regulate two large reservoirs in Voyageurs National Park in northern Minnesota. These new procedures were expected to restore a more natural water regime and affect water levels, water quality, and trophic status. Results of laboratory analyses and field measurements of c