Hydrology

The analysis can compare groundwater elevations, well records, stream stages, pumping information, geologic conditions, precipitation, and seasonal measurements to determine how water moves between the subsurface and nearby streams, lakes, or wetlands. Streams can gain water from groundwater, lose water to the subsurface, or do both along different reaches, making that interaction important when the source or movement of water is disputed.

Removing groundwater can lower local water levels and change hydraulic gradients, which may alter the direction or rate of groundwater movement. A hydrology expert can examine pumping rates, well locations, water-level records, aquifer characteristics, discharge locations, and conditions before and during dewatering to determine whether the activity materially changed the site's water regime. The significance of those changes depends on the hydrologic setting and the evidence available.

Flowing water can erode, carry, and deposit sediment, and the amount moved can change substantially with stream velocity and discharge. In a dispute involving a channel, reservoir, erosion, deposition, or a high-flow event, a hydrologist may compare streamflow, sediment measurements, channel conditions, and changes over time. Sediment can move as suspended material or along the bed, and high-flow events can transport substantially more material than ordinary conditions.