How much pressure does a rain-collecting barrel put out?

Question

In my state it is still legal to collect rain water in barrels. I was considering it to water plants and bushes around the house. How much pressure do these things put out? Is it a dribble, sprinkle, or could I wash the Pontiac?

Thank you.

Answer 1

Pressure is a function of how much water is in the barrell and the size of the outlet.  

But it doesn't take long to empty 50 gallons using a regular garden hose.  You can use the outlet valve to do a very nice drip watering job though.

Answer 2

900 mb

P.S.-Why drive a Pontiac when you can drive a Mercedes-Benz?

Answer 3

Only if the barrel was 30 or 40 ft off the ground(that's a high roof) fresh water puts out about 1 lb psi  per foot of height.

Answer 4

No pressure, unless you keep the barrell up on the roof.  The water will just find it's own level.