The Niikappu River flows south to southwest from
Mount Poroshiri in the
Hidaka Mountains. The river flows through four dams, including
Niikappu Dam and
Okuniikappu Dam. Both dams are owned by the
Hokkaido Electric Power Company, Inc. The dams form Lake Niikappu and Lake Poroshiri, respectively. After , the river empties into the
Pacific Ocean. ==References==