There are many great web applications out there for doing basic analyses. Here is an incomplete list of a few that you may find useful.
OpenTopography is an excellent resource for publicly available airborne LiDaR. You can visualize the data through their portal in GoogleMaps. They also feature a LiDAR Point Cloud Data Distribution and Processing web application, that allows you to build DEMs and derived surfaces from raw LiDaR data hosted on their server for an area of interest that you define. They also have a tool portal to download other useful tools.
StreamStats was developed by the USGS to allow you to easily obtain streamflow statistics, drainage-basin characteristics, and other information for user-selected sites on streams. Typically, such information was only attainable at gaging stations, but using some simple regression equations (user beware... read background) flow statistics can be derived for ungaged basins.
The StreamStats tool is available in states listed here.
surface water, groundwater and water quality. There is also an interactvie GoogleMaps Mapper web application, to locate all stations.
River Links >