As early as the 18th century, there were several on-going waterway regulation projects in Finland, the goal of which was to create much needed arable land. The production capacity of land cleared for cultivation by burning woodlands began to deplete, and the cattle feed gathered from natural meadows was no longer sufficient for the growing demand. The government sponsored the projects by granting rights of tax-free ownership to people who drained swamps and cleared other uncultivable land, including alluvion land, for cultivation.

During that time, the idea of lowering the surface of Höytiäinen Lake began to take shape in the minds of the people as they pondered over ways to obtain more land for cultivation. Furthermore, residents wanted to do something about the repeated flooding of the Viinijoki River by which Höytiäinen drained into the Viinijärvi Lake.

In the 1850s, calculations were made to determine the various possible alternatives for lowering the surface of the lake. It was decided that a 6-km aqueduct to Pyhäselkä Lake would be built. The surface of Pyhäselkä Lake was nearly 21 m lower than Höytiäinen Lake. Digging for the aqueduct began in April 1854 and in 1856 diggers had reached Höytiäinen’s southern-most bay-head. In the autumn of 1858, two dams were built at the upper end of the aqueduct, which were used to regulate the flow of water. The water was allowed to erode and expand the aqueduct with the help of humans. However, the water began to trickle over the dams, which were built on sandy ground, and it weakened the land around them. On August 3rd and 4th of 1859, the dams finally cracked and water from Höytiäinen Lake rushed with fury toward Pyhäselkä Lake. Within a couple of weeks the surface of Höytiäinen had decreased by 7.5 m until rock bed at the bottom of the aqueduct was exposed and the rush of water subsided. The Puntarikoski rapids, which were created as a result, were cleared the following year and the surface of the water decreased another 2 m for a total of 9.5 m in all.

Known as the sea of Karelia, Höytiäinen Lake, which was previously one of the most expansive lakes in Finland’s inland waterways, had been curtailed in area by about one-third. The number of islands of more than one hundred square meters increased from 130 to 516, and many old islands became ‘attached’ to the mainland. A total of 15,700 hectares of land became exposed primarily in the lake’s more shallow areas on the north and northwestern sides. The area was divided among the 165 farm-owners who had participated in the waterway regulation project and whose farms were primarily located on the lake’s east shore, however. For this reason, an abundance of new settlers from villages in Kontiolahti moved to the best meadowlands on the Polvijärvi side if the lake. Throughout the decades, more than 6,500 hectares of alluvion land was cleared for field use. More than 5,000 hectares of this land was in the municipality of Polvijärvi.