Water backup insurance?

I'm buying a house this month and trying to work out the house insurance. My ins is quoting me an extra like 150$ on the premium for water backup coverage, but I'm not sure if I realistically need it. Everywhere I search online says everyone should get it, but I'm not so sure.

The house is in an HOA where every property is required to have a check valve going to the sewer, so theoretically you couldn't get sewage backup into the house anyways. Additionally there is no sump pump and the house is built on a crawl space foundation with nothing in the crawl space. I checked the sewer maps and the house is much closer to the start of the sewage network it's on than the end of it. Given my situation, would anyone think that I am fine without the extra insurance or should I still get it anyways?