The main purpose of Runcu reservoir is to provide the water supply for the population and industry of Baia Mare, Baia Sprie, Sighetu Marmaiei and their neighboring localities, as well as of the localities along the Mara, Iza and Tisa rivers.
The number of inhabitants in the area that will benefit from the water supply is about 300 thousand, which represents over 60% of the Maramureș county population.