Water reuse measurement | Sustainability

Karadeniz Technical University (KTU) has launched a campus-wide Water Recycling Program that combines rainwater harvesting with greywater reuse to reduce potable water demand in non-potable applications. The system captures runoff from building roofs and hardscapes, regulates peak inflow through flow-control hardware, stores water in underground tanks, and then enables the transfer of water from the storage tank to the utility water line for designated uses (e.g., toilet flushing loops, technical/cleaning taps, irrigation manifolds). Governance and operating principles are defined in the University’s sustainability and water reuse policy (published online), and implementation is being phased across campuses with standardized O&M procedures.

System Description & Current Use

Rainwater harvesting & storage: Roof and paved-area runoff is screened, routed through flow-control devices, and buffered in underground tanks sized for storm peaks and short-term reuse.
Distribution to end-uses: Recovered water is delivered via a dedicated line to toilet flush reservoirs in selected pilot buildings and to technical utility taps for cleaning/maintenance. Where practical, the recovered line is valved for future connection to irrigation and vehicle-washing points.
Quality & safety: Simple pre-filtration is applied for toilet/utility uses; additional filtration can be added when irrigation/vehicle washing connections are commissioned.
Operations: Tank levels and make-up/overflow events are logged; periodic disinfection and screen maintenance are scheduled per O&M plans.

Policy, Planning & Compliance

Policy basis: KTU’s published sustainability and water reuse policy formalizes objectives, roles, and permitted reuse applications, including rainwater and greywater, in alignment with WR4.2 evidence requirements.
Planning status: Campus engineering has completed a reuse roll-out plan that prioritizes high-use buildings for toilet-flush integration, followed by grounds irrigation and fleet-washing stations.
Technical note (integration): The program standardizes the “transfer of water from the storage tank to the utility water line” with backflow prevention, labeling, and isolation valves to maintain potable–non-potable separation.