In the presented work we evaluate optical sensors in human interface devices for the velocity measurement in environmental surface water. The evaluated sensors are the ADNS-9800 and the similar ADNS-5020 based on close range CCD image capturing and optical flow analysis. The evaluation is aimed to observe the general characteristic of the sensors and test the feasibility of use especially in flood water applications. The investigations are performed in two parts. In the first part the general characteristics of the sensor with special regards to different materials and surface patterns. In the second part of the sensor is tested to obtain information on flow of media. The results are summarized and discussed in regards to the intended application.