Need advice related to city sewer backups

We live in a home built in the mid-70's in a neighborhood with a combined storm sewer system...where the lift station sits just down the street. Unfortunately, the city's lift station doesn't have a permanent generator and seems to be severely undersized...so we experience backups several (3-5) times per year.

We've installed a check-valve in our crawl space to protect from backups entering our living space. However, as the backups can sometimes last for several hours or even a few days, it is nearly impossible to live in the house since we can't put water/waste down the drain during this time.

I know our problem is not unique as many other "older" neighborhoods have combined storm sewer systems. So I'm curious what advice y'all might have regarding how to best remedy the situation in order to maintain a somewhat normal lifestyle during these times.

Any and all advice is appreciated. Thanks!

I don't condone this, just mentioning it

In a blighted urban area in kentucky, they suffer the same situation.

If a group of you get together and bring forth facts that your system is not functioning according to per say code due to their failing system,

you can hold the city liable for disposal fees of sewage. Meaning, they paid to have a company drop a container off where sewage was pumped into it, then the company returned to dispose of it.

Very VERY expensive and the city "instantly" got a budget together to reline/repair those 70+ year old systems in a safe and sanitary condition.

sewer

A company in Chicago used to make a backwater valve/pump unit for those situations. The backwater valve was positioned under a pump chamber. During a backflow situation, the valve closed. Any seepage through the valve, or water used in the building filled the sewer then rose into the pump chamber. When the water level was high enough, the pump "ejected" the water out into the flooded city sewer. A good plumber can reproduce this system with a backwater valve and a "sidearm" ejector pump.