Time-Lapse Photography: Low-Cost, Low-Tech Alternative for Monitoring Flow Depth

Streamflow information is collected worldwide and used in the areas of engineering design, water supply planning, and hydrologic and water quality analysis, among others. Available data from intermittent and ephemeral streams in arid regions are sparse because streamflow is highly variable and infrequent. Due to a lower perceived priority to monitor intermittent and ephemeral streams, it is more difficult to justify the economic expense of traditional monitoring equipment. This study demonstrates that time-lapse photography can provide a viable, low-cost, low-tech option for measuring stage (water depth) at stream gauging stations. A time-lapse camera was set up to record images of a channel and staff gauge in an ephemeral urban catchment in central New Mexico. During flow events, stage can be read from the time-lapse images and converted to a discharge time series. In the course of a 2-year test period, 33 runoff events were recorded. With approximately $200 in materials, this method costs only a fraction of conventional gauging stations.