A have a dear friend who loves data, is so good at it, and also loves data fun facts. She shared one with me that will make your life (and possible guilt) easier:
People think they are saving water when they hand wash their dishes, but! The on-average threshold for saving more water in the dishwasher vs. hand washing is… 8 dishes. If you have 8 dishes and only 8 dishes (on average; the size would matter too) you will save more water if you wash them in the dishwasher than washing them by hand.
When I run my dishwasher, I always have more than 8 dishes in there, but this has completely eased my guilt at wanting to have it full the brim. You’re doing a good thing! Feel no guilt!
–Renee Roederer
Smuggling Grace 