Val-
This is a topic close to my heart as a teacher and school admin! I just sat my teachers all down this summer and had a big heart to heart. Why on earth do we give kids 3 hours of homework?
Well the answer that I got was "Oh we don't!" but I had surveyed a large population of students, both high achievers and struggling students. The average I got was 2.5 hours in middle school.
What I discovered was that teachers are notoriously poor estimators of how long it will actually take a kid to do something. They are, in theory, experts in their subject area and any work given would not be practice for them.
No idea if your kids' administration would be receptive but we had a great experiment. I had the teachers all swap homework with another teacher and actually DO it for a week. Guess what? It took most of them 2.5 to 3.5 hours!
We established a new policy as a staff that homework for middle school should be no more than 1.5 hours a night, including independent reading time that they are required to document. One month into the school year and it seems that most students are doing about 1 hour a night now. I find this pretty reasonable since they are allowed to choose any type of book for independent reading and that is 20-30 min a night (we require 2.5 hours a week documented)
Long story short- there IS something you can do about it. I would highly recommend keeping a calendar for two weeks of how much time your child spends doing homework. Actual time, not going to the bathroom, getting another snack, texting time. Take it to the particular teacher or to the admin and discuss if they think it's reasonable. Chances are, they have no clue how long it's actually coming out on the back side.