Water Act (WsG)(724.1).

This Cantonal Water Act (WsG) of Zurich regulates the ownership, management, protection and use of all public and private surface and groundwater, setting objectives for safeguarding water bodies and their required space, flood protection, revitalisation, biodiversity, water quality, wastewater disposal and sustainable water use. It defines key terms, establishes cantonal authority over public waters, provides procedures for determining water status and boundaries, and mandates a cantonal water strategy and binding implementation planning. The Act assigns planning and operational responsibilities to the canton and municipalities, regulates land‑reclamation concessions, water‑space designation, and construction or interventions in water bodies and water spaces. It sets rules for flood‑risk mapping, emergency planning, water‑construction projects, object‑protection measures, and ecological maintenance. Financing provisions govern cost‑sharing, contributions, and subsidies for flood‑protection and revitalisation measures. The Act also establishes cantonal permitting requirements for installations and activities affecting water quantity or quality, including wastewater systems, hazardous‑liquid installations, energy‑use systems, and material extraction, forming a comprehensive framework for water governance, protection and sustainable use in the Canton of Zurich.