Outlets come in various forms, including the single-letter, double-letter, and gate styles. The placement, form, and flow rate of the outlet of the drainage channel should be determined based on factors such as the quality of the effluent, downstream water usage, the flow and water level fluctuations of the body of water, dilution and self-purification capabilities, flow direction, wave conditions, topographical changes, and meteorological factors, and must obtain approval from the local health and navigation management authorities. Measures such as anti-erosion, energy dissipation, and reinforcement should be taken at the connection between the outlet and the water body's shore, typically using mortared blocks of stone for the retaining wall and base. In areas affected by frost heave, the outlet should be constructed with frost-resistant materials, and its foundation must be set below the frost line.