Sandfangs

Sandfangs are hydraulic structures installed at the inflow of water bodies, channels, or pipelines to remove sand and coarse sediment from runoff or intake flows. The primary purpose is to protect pumps, turbines, and downstream equipment from abrasion and clogging, reduce wear, and improve water quality.

A typical Sandfang consists of a short inlet section that directs flow into a sedimentation basin or chamber where velocity is reduced, or a series of baffles and a collecting sump that traps sand. Clarified water exits while settled material is removed periodically. Materials commonly used include reinforced concrete, steel, or durable plastics. Some designs incorporate screens or coarse filters to prevent larger debris from entering the sedimentation zone, and bypass arrangements may be included to handle peak flows.

Sandfangs are used in water-supply intakes, irrigation canals, stormwater and industrial drainage systems, and inline pipeline configurations where sediment load is significant. They are often integrated with grit chambers or sedimentation basins and may feature debris racks, screens, or diversion options to manage organic matter and large particles.

Maintenance is essential. Settled sand is typically removed on a scheduled basis through manual extraction, pumping, or vacuum equipment. Effective designs aim to minimize sediment resuspension and odors, and installations should comply with local codes and standards for civil engineering, environmental protection, and flood safety.