The Oddatjørnd dam is a rock-filling dam with a seal core of moraine pulp that (along with 13 other ponds) dammes the artificial lake Blåsjø. It is constructed as a conventional stone filling pond, with coarser material the farther from the core one comes. Down the densely packed moraine core, there are gravel layers in various gravities, and then rocks. Finally, it is patched with large stones laid on stone by stone. The dam was built as part of the Ulla-Førre development to contain the Ulladalsåna river, and with its 142 meters is the highest filling pond in Norway . The dam crown is 446 meters long, the largest cross-section at the bottom is about 400 meters, and the filling volume is 5.75 million m³. Below the pond lay the brackish camp Øvre Moen, which housed up to 400 workers. The water tunnel to Saurdal power plant runs from Blåsjø at Oddatjørndammen