Stoplogs

Stoplogs are modular boards or panels used to regulate water levels in channels, dams, canals, and similar structures. Each board fits into vertical guides or a stoplog well, and a stack of boards can be added or removed to adjust the upstream water head. When in place, stoplogs form a temporary barrier that reduces or holds back flow; removing boards allows water to pass more freely or to dewater a section.

Construction typically comprises individual boards, guide slots, end closures, and sometimes anchors or seals. The boards are designed to fit tightly in the guides to minimize leakage while permitting easy handling when adjustments are needed. Stoplogs can be operated manually, with simple hoisting equipment, or as part of a larger gate system. Proper seating and alignment are essential to prevent seepage and to avoid misalignment that could lead to panel binding or damage.

Materials vary by application and environment. Common options include wood (timber), steel, aluminum, and composite materials. The choice depends on factors such as durability, corrosion resistance, weight, and maintenance requirements. Stoplogs are typically used in places where precise, frequent adjustments are impractical for motorized gates, or where a simple, cost-effective solution is preferred.

Applications span irrigation canals, flood-control channels, water treatment and intake structures, spillways, and some hydroelectric facilities. Maintenance focuses on inspecting boards for warping, rot, or corrosion; ensuring guides are clear and undamaged; verifying proper seating; and using safe handling practices when stacking or removing boards. Safety considerations include securing the stack, preventing sudden releases, and adhering to lockout and signaling procedures during adjustment.