The ability to monitor the stormwater capacity of green roof systems is probably the most important environmental application of sensor networks for green roofs.
Green roofs are designed to capture at least a 1-inch rainfall event, but this capacity is site-specific and should be monitored to ensure the long-term effectiveness of green roofs for this purpose.
Having the capacity to remotely monitor and control irrigations is probably the most important management requirement for most roof top environments, since they are remote (often inaccessible) and plants experience high wind and evaporative losses.
We need to ensure the survival and the capability of green roof plants to reduce the amount of water in green roof substrates between rain events (since this increases the efficiency of green roofs for stormwater mitigation). However, during periods of drought, an automated irrigation system that can irrigate to optimize plant performance is required in many regions around the US. A relatively small investment in this capability could potentially save large plant maintenance and replacement costs during the life of a green roof.