RoofRainYield

Springfield, MO rainwater: 36,966 gallons off a roof

How much rain a roof in Springfield, MO collects

36,966gallons a year

That is a 1,500 sq ft asphalt roof under Springfield, MO's normal 46.5 inches of rain, about 795 gallons for every inch that falls.

In Springfield, MO a single barrel does most of the work. Storms come often enough that a small tank refills before it runs dry, and a bigger one would mostly sit full.

Rainfall: NOAA 1991-2020 climate normals, the Springfield Wbo station (0.6 mi away). Springfield, MO ranks 12th wettest of the 80 cities covered in Missouri.

Month by month in Springfield

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan2.441,939
Feb2.421,923
Mar3.722,957
Apr5.204,133
May6.054,809
Jun4.943,926
Jul3.873,07660
Aug3.572,83797
Sep4.453,537
Oct3.602,86194
Nov3.612,869
Dec2.642,098

May is the wettest month (6.05 in, 4,809 gal off the roof); Feb the driest (2.42 in). Garden shortfall is what a 200 sq ft vegetable bed needs beyond the rain that lands on it, April to October.

Which tank size is worth it in Springfield

Best fit: one 55-gallon barrel, which delivers about 200 gallons to the garden in a normal year (79.8% of its need).

If you buy one, a 55-gallon barrel with a downspout diverter is the whole job. Check that the overflow points away from your foundation, because most of Springfield's roof water will pass straight through it.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal20035,641
110 gal20035,641
165 gal20035,641
275 gal20035,641
550 gal20035,641
1,000 gal20035,641
1,500 gal20035,641
2,500 gal20035,641
5,000 gal20035,641

Simulated storm by storm through a normal year using the station's count of days with 0.1 in or more of rain each month.

Is rainwater collection legal in Missouri?

No rainwater harvesting regulations

From the 2015 (Pacific Northwest National Laboratory report 24347); not yet re-checked against current law, so check with your state water agency before building anything large. Source