A headwall is a concrete frame poured around a beveled culvert end. It provides structural support to the culvert, eliminates the tendency for buoyancy and provides inlet and outlet protection. A headwall is a required end treatment for all culverts that range in size from 4 to 10 feet. Contact the RHE for direction on headwalls required for culverts smaller than 4 feet. Headwalls shall be used on all thermoplastic culverts, 30 inches in diameter and larger. A typical headwall is shown on Standard Plans B-75.20-03 or in Figure 3-6. When the culvert is within the clear zone, the headwall design can be modified by adding safety bars. Standard Plans B-75.50-01 and B-75.60-00 provide the details for attaching safety bars.
The PEO is cautioned not to use safety bars on a culvert where debris may cause plugging of the culvert entrance even though the safety bars may have been designed to be removed for cleaning purposes. When the channel is known to carry debris, the PEO shall provide an alternative solution to safety bars, such as increasing the culvert size or providing guardrail protection around the culvert end.
