Pumping rain Rain water needs to be taken out of Home Sewers - Gravity problem
Can an outdoor sump pump safely handle the rain water off of the back of my jhouse (about 15 squares), my patio water (20 X 30 space concrete, and a sump pump from my basement that pumps currently into my sewers but needs to be rerouted to this same outdoor source? In other words, how much water is too much water for an outdoor sump? Also, any info on a back-up generator for this outdoor pump?
You need to find out what the capacity of the pump is in gallons per minute, and also figure out the square footage of the space you are trying to drain. For example, if you have 1000 square feet of surface area, a good rule of thumb is 1 gpm for every 24 square feet of surface area for a worst case 4" per hour storm will give you the gpm requirement. So, for 1000 square feet divided by 24 = 41.6 GPM pump. Then you need to figure the friction and elevation losses, so if your rising 10 feet off the pump before the water spills to gravity you need to factor in a 10 foot head loss when selecting a pump which will effect the gpm rating.