You don’t have a problem! You just need another tank because your tank is OVERFLOWING!
The first time your tank fills is exciting! Even though we do the math and know how much rain it will take to fill tanks, people are still surprised their tank fills so quickly. Others have already experienced rain volumes filling trash cans and 55 gallon drums in a matter of minutes, so they aren’t surprised when 500 gallons or even 1500 gallons fills in a single rain event!

Once tanks start filling with water, they may settle and shift, so we may see some unexpected results. This particular joint is the overflow. Generally, we prefer not to glue pipes onto this joint in case we ever need to reconfigure or clean your rainwater tank. Sometimes tanks settle and this pipe needs to be reworked. Other times, we need to configure new overflow routing if the landscape plan changes. If the elbow is secured on this joint, you shouldn’t see a leak.
We often see some water leaking from behind the black gasket where the fitting is fastened to the tank. This doesn’t mean you are losing water since your tank is already full and this water is going to overflow anyway. So unless the volume is extreme, this is not necessarily a sign that you need to fix anything. If the volume is concerning, or your tank is placed in a location which is sensitive to this drip, here are a couple things you can do:
- hand tighten these screws (a driver/drill may strip the screws)
- use silicon to help seal around the gasket (make sure everything is dry so the silicon will seal)
- open up the lid of the tank and look inside to see if the screen at the overflow is clogged from the inside. Sometimes small clay particles make it past filters and wind up in the tank clogging the overflow filter screen. In the last few years, Bushman has been making these screens removable, but if you have an older tank, you may need to remove the entire overflow assembly to clean it.
- if the drip is extreme or none of the above fixes the problem, you may consider requesting a new fitting for the tank.
This is a more extreme leak at an overflow joining two tanks. Here is a case where the filled tanks have shifted and the pipe needs to be pushed back onto the overflow joints
We love hearing our CatchingH2O clients, clients of other installers, and homeowners who are troubleshooting their own installations! The more we see how these systems perform over time, the more information we will have to share! Tell us what is working and what isn’t! After installing hundreds of thousands of gallons of water storage, with hundreds of tanks ranging in size from 205 gallons to 5050 gallons throughout Southern California, CatchingH2O is leading the local industry in experience with these simple systems. We thrive on sharing our knowledge and experience with you!
If you are excited to see your tank overflowing and wanting to get the next tank in place to store more water for the long dry season, contact us now! We love to see gardens thriving in the summer time without guilt!