Begin with the question you are trying to answer. Lake level, river flow, gage height, water temperature, tide prediction, and water-quality sample are separate data products.
Next, verify the location. A station can be on the waterbody, at an inlet or outlet, upstream, downstream, on a tributary, or merely nearby. Distance alone does not prove that a reading represents your destination.
Check the timestamp, expected reporting interval, approval status, qualifiers, unit, and datum. For coastal water, distinguish an observation from a prediction. For water quality, distinguish a continuous sensor from a dated sample and an official advisory.
Finally, look for official alerts and local information. Data can support planning, but it does not replace weather awareness, posted rules, local expertise, or direct observation. Save the useful station—not just the waterbody name—when you create an alert.