Here's a link for rain gardens and bioswales. You should have gutters and downspouts though to move the water away from the foundation of the house and to the rain garden, especially if you get that much rain during a single event.

https://www.soils.org/discover-soils/soils-in-the-city/green-infrastructure/important-terms/rain-gardens-bioswales

I have an intermediate sized trash can placed to collect the run-off from my roof. When rain is not forcast, I put the lid on to reduce evaporation. To get the water out, I use a small bucket. I only have a couple of plants that do not tolerate our SoCal water pH, so the one trash can will last all year and it's not too much of a pain to hand water the plants. You could buy a fancier distribution system, but it'd probably go unused most of the year as you rapidly emptied the rain barrel once the dry season begins.

I use trash barrels also. Much cheaper than what is sold as rain barrels. Then I stack them to store in the dry season. Sometimes you can get free 55 gallon plastic drums--it was suggested to me to try asking at a car wash as they buy detergent in those drums, but I've never tried doing that myself.

You can find 55 gallon poly drums on Craigslist pretty cheap. Far more useful in our climate are the 275 gallon IBC totes that you can find on Craigslist for $120.

Thanks for the advice everyone! The reason we dont use gutters is that when it does rain it overwhelms them anyway. Our drains were overloaded during the last storm by extra pool water which drains into the main drains, so I would need to use a french drain in some areas. I just feel bad that we get so much rain, but can’t really use it.

"The reason we dont use gutters is that when it does rain it overwhelms them anyway."

From a drainage perspective, this makes no sense. You are basically saying that because say 10% of the water overflows the gutters, it's ok to have 100% overflow the gutters. The solution to overwhelmed gutters is larger gutters, more downspouts, or possibly just a small baffle on a part of the gutter system depending on how it overflows.

You are permitted to connect your backwash drain for your pool filter to the sewage line but connecting the pool overflow to the sewage line is illegal in CA btw.

I don't want to discourage you, because I like the idea of collecting rain water and before a rain I put out as many containers as I can to catch it. That said, a friend of mine spent a good sum of money on a rain collection system to direct rain from the gutters of her house into a series of rain barrels. It works great. Her husband is an engineer and he made a point to state that at the current price of water it would take more than their lifetimes to recover the cost of that system. My suggestion: put a couple of trash cans at those roof interfaces.