Culverts along the first flat road in a canyon bottom might only need to be 18 inches in diameter, Camp said. “But every time you go up a layer, there’s more water coming downhill,” he ...

Hanson Pipe & Precast provides 2,566 linear feet of precast concrete box culverts to allow natural groundwater flow and support for machinery at working mine.

Nonindigenous species tolerated higher flows, so culverts may create a filter that favors the spread of invasive species. Culverts should be designed to keep water velocity <30 cm/s to mitigate flow ...