# Filling city pool - how fast?

How quickly can a city fill a swimming pool that holds 200,000 gallons? The figures a city employee gave me would indicate they were pumping in 3000 gallons per hour. Is that even possible?

3000 gallons an hour sounds reasonable to be… and it would take a little over 2 1/2 days to fill the pool. Why does that surprise you? There are huge pumps that can move water a lot faster than 3000 gallons an hour…

A standard garden hose is about 5-10 gallons per minute or 300-600 gallons per hour.

When I managed apartments, we had a pool that was only 20,000 gallons and when we needed to drain and refill it, we used two garden hoses at once to get the job done in about 6 hours.

To get to 3,000 gph would take take a few garden hoses, but a swimming pool that big would obviously be using something with higher flow. In fact, 3,000 gph isn’t all that much; even my koi pond has a 5,000 gph pump. A single 3" hose can deliver as much as 25,000 gph (cite with lots of other numbers for comparison).

Given that 3000 gph would take almost 3 days (67 hours) to fill a 200,000 gallon pool, I almost wonder if the city employee is wrong about the flow rate.

Fire departments sometimes get called upon to fill swimming pools. A 200,000 gallon pool is not so huge.

An Olympic sized pool (50m long, 2 m deep, 10 lanes wide) is about 660,000 US gallons. A deeper section such as a separate diving well adds a lot of volume.

It is certainly possible to pump well in excess of 3000 gal/hour A low capacity fire department pump might only deliver 500 gallons per minute. The capacity of the hydrant is often the limiting factor in using higher flow pumps. The local Volunteer Fire Dept where I grew up had pumps up to about 1200gpm.

ETA: At 500 gpm it would still take 6hr 40 min to fill a 200,000 gal pool if you can pump at that rate non-stop.

My 355,000 gallon community pool filled from a 4" water line in 8 hours.

When I was in the Coast Guard, there was nothing special about a 250 gpm pump. That could pump 15,000 gallons in an hour. The small ones were 90 gpm. They can pump 5,400 gallons in an hour.

How do they fill swimming pools in Munich?

Mark Spitz.

Because it just didn’t sound legit to me. More to the story – the pool has a leaky filtration system. Depending what figures are to be believed, they would have had to pump in a minimum of 2400 gallons per hour to keep it filled.

News stories… What is the idea of pumping ? Pump from where to where ?

Why wouldn’t the regular town mains by filling the pool ?
The pool is leaking. Maybe the pump is collecting the leaking water and returning it, so as to neutralise the leak.