When we think about indicators of water, we think of natural elements like rain, lakes, rivers, ponds, seas or oceans. But how do we think about indicators of water as we walk through a busy city street? Is it directly visible or is it indicated through some other infrastructure or system?
The idea is to understand where we find water in the urban realm when we can't directly see it. Through such indicators even though there is an absence of water itself, we know that there's water underneath in some form.