WASHem is really suggesting to get a minimal information to start the response rapidly. Usually, the projects spend more time to establish baseline DATA to start responding to the immediate needs. This tool is really a good approach as the bare minimum DATA collection collected and start the response as early as possible. This definitely safe lots of lives. 

In emergency situations the most deaths occur at the beginning. It is due to lack of infrastructure, the inability for the people to identify risk spots due to shock, lack of interest as they might lost their important people or thinks due to disaster and so on. So the earlier the best to safe lives than spending time to get base line data.

One other interesting thing about WASHem is that it suggests to get videos, and interpret the findings. But it is purely on the data collectors perspective. The findings will be different from one person to the other. However, it is worth using this tool, rater than not doing any to protect lives..