L&G has an abundance of knowledge and resources enabling them to perform accurate Hydrologic Studies. Hydrologic studies are the basis for all hydraulic design. Hydrologic studies include rainfall and runoff determination, reservoir routing, and channel routing.

 

To determine the amount of runoff that needs to be accounted for, watershed delineation, soil, and land cover information are key requirements. Obtaining watershed and sub-basin boundaries (utilizing USGS quad maps/L&G GIS databases), soil, and land cover information is essential early in a watershed planning project to help determine what kind of flows to expect in order to properly size outfall structures, whether it be a culvert or an open channel. To assist in watershed delineation, L&G has developed a comprehensive GIS database detailing all local drainage patterns including watershed basin and sub-basin areas.

 

Another important factor in Hydrologic Studies is flow determinations. Knowing peak stream flows can be useful as communities develop stormwater discharge ordinances. It can also be used with cross-section data to determine stream velocities needed, for example, to design proper slope protection.

 

Hydrologic modeling can be used to determine the impact of land uses changes and best management practices (BMPs) on storm flows. This information may be useful for long-range planning efforts, community stormwater ordinances, and BMP selection, design, and evaluation.