The storm drains in my house are the plastic ribbed type that run under the garage. When it rained heavily water backed up. It eventually drained, but I was worried that heavy rain can force water into garage. And then I learned I had blockage.

The contractor I first contacted wanted to rip it out. Big dollars for sure. I finally found one that was willing to help.

They took a better look and realized that there was a bloackege from some conrete that had slipped in.

Problem solved.

But they thouht there might be more.

They told me how to fix it myself.

Though they thought it wouldn't be necessary, although if it becomes necessary it may not be a horrendous big deal. You can rent a jack hammer/chisel and trench out the drain--then replace and fill with gravel and top off with a few inches of concrete. I've done small patches like that and while it's obvious it is a patch if you do a reasonably careful job--epoxy garage floor paint (2 part system--covers a multitude of sins.

If you can determine where the outlet is you may be able to put a smaller diameter sleeve in and route the outlet to a catch basin but either way the water is probably not draining out from the pipe along its length as intended but seeping out or flowing out-albeit slowly from the outlet end.

It still drains slowly. So far it hasn't been a big problem. If I can't remove the cement, the only other way is breaking up the concrete driveway which I don't want to do..