Issues affecting the utility and accuracy of water level measurements for storm surge are addressed. Vertical datum control (including land elevation measurements), water level sensor survivability, and sensor placement are critical to obtaining useful information on storm surge. Hurricane Dennis in 2005 provides an example of how water level measurements are used to evaluate and improve storm surge prediction models. A water level gauge operated by the University of South Florida Coastal Ocean Monitoring and Prediction System (COMPS) was the only site to capture time history of the maximum surge that occurred in Apalachee Bay, Florida, leading to improvements in the storm surge prediction model. A more dense network of water level gauges, as a component of the U.S. Integrated Ocean Observing System, will enable a more efficient response to and mitigation of future storm surge events.