DIY School
D. Gallons per minute available
· Using the previous information, refer to this chart to determine how many gallons per minute (g.p.m.) are available for your system.
· Example: With a meter of 5/8”, a service line of 3/4”, and water pressure of 55 p.s.i. you would have 10 g.p.m available.
Determining Gallons per minute
Find your available g.p.m on the chart and write it in below:
| Size of | ||||||||||
| Water Meter | Service Line | Water Pressure ( p.s.i. ) | ||||||||
| 30 | 35 | 40 | 45 | 50 | 55 | 60 | 65 | 70 | ||
| 5/8” | 1/2” | 2.0 | 3.5 | 5.0 | 6.0 | 6.5 | 7.0 | 7.5 | 8.0 | N/A |
| 5/8” | 3/4” | 3.5 | 5.0 | 7.0 | 8.5 | 9.5 | 10.0 | 11.0 | 11.5 | 13.0 |
| 3/4” | 3/4” | 5.0 | 7.0 | 8.0 | 9.0 | 11.0 | 12.0 | 14.0 | 15.0 | 16.0 |
| 3/4” | 1” | 7.5 | 10.0 | 11.5 | 13.5 | 15.0 | 16.0 | 17.5 | 18.5 | 19.0 |
Note: If your service line is longer than 75 feet from the main source or is old enough to have corrosion inside, a simple flow test can be performed. Time how long it takes to fill a bucket of a known size, from one of your outside faucets. Convert this to gallons per minute using the following formula:
Bucket size ( in gallons ) x 60 = G.P.M
Seconds to fill
Example: A two gallon bucket that fills in 15 seconds means that available flow is eight gallons per minute. (2 x 60) / 15 = 8 G.P.M
E. Draw your Layout Plans:
In addition to the information above you’ll need an accurate scale drawing of your yard. Check this list to make sure you have included everything:
1. Outline of house and other buildings
2. Patio, sidewalk, driveway and deck
3. Fences, walls, and planters
4. All lawn areas
5. Trees, shrubs, ground cover and garden beds
6. Location of water source and service lines
7. If your water is supplied by a pump, show the location of the pump and well
Now label the parts of your drawing, and lightly shade in those areas to be watered.
