Catchment costs?

[ckg]

Messed up on my last post. I figure catchment will be a real consideration as the flow could certainly take out the roughly mauka land of Keonopoko or enough people may leave to make for a poor business model where they may need to close the water company. Just trying to stay ahead of the curve. Once a catchment is operational I figure a once a year cleanout and filter change for maybe a few hundred a year in maintenance or am I completely off in what it costs to maintain a system once installed? What does the ongoing maintenance look like in work and cost?