No, you do not need a garbage disposal to have a dishwasher. A dishwasher will work without one, and while it's rare to see a home with a dishwasher that doesn't have a disposal, it is possible. The two appliances pair well and are often installed together because a disposal simplifies meal cleanup.

However, your dishwasher should not be used as a replacement for a garbage disposal. Subjecting it to continuous food leftovers can lead to major clogs. If you choose not to install a garbage disposal, you should thoroughly rinse your plates or scrape excess food into the trash or a compost pile before loading them into the dishwasher to prevent plumbing issues.

Garbage disposals can be considered bad for the environment due to their electricity usage, but good for the environment because they reduce the food waste sent to landfills. If everyone used a garbage disposal, it would tax the wastewater treatment facilities in that region, but if we had to choose one of the options, we’d say they are a net positive on the environment when used correctly. 

Most garbage disposals have a reset button that can be triggered with a tool as simple and accessible as your index finger. That said, if you need to perform a more in-depth troubleshooting step, like manually moving the arms inside the unit or rotating the impeller plate, a hex wrench is the most common tool you’ll need. Most garbage disposals come with a hex wrench.

If the cost of repairing a leaking garbage disposal is close to the cost of replacing the disposal, then fixing the unit might not make sense. When deciding if you should repair or replace your garbage disposal, consider the age of your garbage disposal, the cost of the repair, and whether your garbage disposal has had other problems recently to help you decide if the cost of repairing the leak is better than the cost of replacing the disposal.