Dortmunder Netz GmbH (DONETZ) is a 100% subsidiary of Dortmunder Energie- und Wasserversorgung GmbH (DEW21). It operates the electricity, gas, and water supply networks in Dortmund and surrounding areas like Herdecke and parts of Holzwickede. Its core mission is the technical and economic operation of these distribution networks, ensuring public supply and non-discriminatory access for all market participants.