Mississippi River Reservoir Dam System

In 1869, the U.S. Army Corps of Engineers began a project to control flow of the Mississippi River, the Headwaters Dams. The Headwaters Dams were a series of six structures built between 1881 and 1912. They were constructed in an effort to improve navigation north of the Twin Cities and prevent flooding. These dams were the headwaters' primary regulatory system until the construction of the Nine Foot Channel in the 1930s.

By the mid-nineteenth century, the Twin Cities were developing industries dependent upon the Mississippi River such as timber and flour milling. The river provided power for the mills and transportation for goods and trade. However, the river's flow changed with the seasons. The changing water levels got in the way of navigation and created dangerous swells. In 1869, St. Anthony Falls almost washed out entirely because of aggressive construction and rising water. Although the Falls were eventually stabilized, the near-disaster prompted the U.S. Congress to ask the U.S. Army Corps of Engineers to investigate the issue.

The Corps acted quickly. By the end of 1869, they had completed a study under the direction of Franklin Cook. In his report, Cook suggested the construction of a single dam located at Pokegama Falls (Itasca County), 170 miles north of the cities. The engineers considered their options and after ten years decided instead to construct a series of dams throughout the headwaters. These structures not only were flood control devices but were also designed to promote river traffic.

In the 1860s, many businesses still relied upon the river, especially grain merchants, flour millers, sawmills, and long distance traders. Railroads got off to a slow start in Minnesota, so were not a good alternative for shipping. Although Minnesota railroad construction had begun in the 1850s, expansion of the roads in the 1860s and 1870s hit many snags. Therefore, river traffic remained key to the success of many Minnesota industries.

Funding for the dams was approved by Congress in 1880 and construction began the following year. The first stage of the project consisted of the construction of three dams. The first dam was built at Cook's original location of Pokegama Falls. Two others were nearby at Lake Winnibigoshish (Itasca County) and Leech Lake (Cass County). All three were constructed between 1881 and 1885. This trio of earth, stone, and timber structures created three reservoirs to slow flooding. They also offered control over water levels, which was good for navigation and reliable shipping.

The Corps of Engineers started building new dams even before the first dams could begin operation and prove their value. In 1884, construction began on the Pine River Dam. The dam was on the outlet of Crow Wing County's Cross Lake, roughly twenty-seven miles to the south of Leech Lake. Like the other dams, this structure also used timber, earth, and stone for its building materials. The local availability of these materials and the engineers' ability to reuse machinery and supplies from the projects at nearby Leech Lake and Lake Winnibigoshish allowed construction to proceed quickly. By 1886 the Pine River Dam was in full operation.

The success of the first four dams encouraged the Corps of Engineers to continue with the project. The Corps constructed a fifth dam between 1892 and 1896. Named the Sandy Lake Dam, it was located near the confluence of the Sandy and Mississippi Rivers in Aitkin County, 120 miles north of Minneapolis. It was also constructed of timber, earth, and stone. However, unlike any of the other dams in the system, Sandy Lake had a lock. The lock allowed ships to move between the different water levels created by the dam.

The dams received frequent attention in the early twentieth century due to their crucial role in controlling the river. Between 1899 and 1908, each of the five original structures had essential wooden and earth components replaced with concrete and metal. Concrete and metal were also used in construction of the final dam, Gull Lake Dam. Completed in 1912 in Crow Wing County, this structure's design utilized concrete to reinforce its wooden components. This transition greatly enhanced the reservoir system's durability.

Within twenty years of Gull Lake Dam's completion, the Corps of Engineers began another project to aid navigation. Although Minnesota railroad systems had eventually become competitive due to developments by James J. Hill and others in the 1870s and 1880s, river transport was still essential, especially in the case of bulky cargo. In 1930, funding was approved for a series of locks and dams located between Upper St. Anthony Falls and Guttenberg, Iowa. Known as the Nine Foot Channel, these locks and dams offered a level of river control superior to that of the Headwaters Dams. The majority of this new project was completed in 1938.

With the completion of the Nine Foot Channel, the reservoir dams became primarily flood control devices. They were renovated throughout the twentieth century to keep them in good shape. The updates included the replacement of the dams' remaining wooden components with modern materials and operational improvements to sluiceways and other control devices. These upgrades have allowed the reservoir system's to remain a key component of Minnesota's Mississippi River control program. In the early twenty-first century the dams remain vital to the state's infrastructure.

The industrial and economic benefits of the Headwaters Dams came with great social costs. The reservoirs were located on American Indian land. Rising water levels threatened to destroy the homes and livelihoods of the nearby Ojibwe. The U.S. government originally offered $15,466.90 in restitution. This sum was immediately refused. Negotiations between Ojibwe leaders and the Northwest Indian Commission lasted from 1881 until 1886. In 1886, the last of the main local tribes agreed to move to the White Earth Reservation in western Minnesota. They ceded their property rights with the move. In exchange, they were promised government-funded improvements at White Earth and payment of interest earned on the proceeds from the sale of the land to private parties. Many Ojibwe found this compensation unsatisfactory. The issue festered until 1985, when the Leech Lake tribe received a settlement of $3,390,288.