Abstract: A headwall structure constructed of lightweight reinforced composite and incorporating a rigid polymer concrete core in selected portions, for use with standard culvert or drainage pipes in infrastructure water management systems in substitution for conventional concrete headwalls. The headwall structure has a vertical back wall with an integral spigot or pipe stub surrounding a central orifice. The pipe stub is preferably cross-sectionally dimensioned and configured to be identical to a selected standard pipe section end so that such pipe section can be connected to the pipe stub without an adapter. A tray is joined to the lower edge of the back wall. A pair of outwardly flared sidewalls are joined to the back wall and to the tray. Angled brace panels extending from the sidewalls to the tray reinforce the sidewalls. The tray, sidewalls and brace panels define the water channels. Front and side brace panels define a recess into which earth enters and against which earth bears to provide stabilization.