The water well indeed has a mechanic that adds water over time. This is implemented through periodic checks that add water based on rain intensity and time intervals. Currently, the fill rate is a random number between 1 and 5 every in-game hour, and additional water is added when it rains, depending on the rain intensity. I will add sandbox options for these features. Specifically, I will provide the ability to change the multiplier for the rain intensity fill rate and provide a method to adjust the hourly fill rate.