Elkton, MD rainwater: 37,698 gallons off a roof
Elkton, MD: gallons off the roof each year
37,698gallons a year
That is a 1,500 sq ft asphalt roof under Elkton, MD's normal 47.4 inches of rain, about 795 gallons for every inch that falls.
In Elkton, MD 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 Newark 3.9 Ssw station (2.3 mi away). Elkton, MD ranks 7th wettest of the 23 cities covered in Maryland.
Month by month in Elkton
| Month | Rain (in) | Off the roof (gal) | Garden shortfall (gal) |
|---|---|---|---|
| Jan | 3.50 | 2,782 | |
| Feb | 2.85 | 2,265 | |
| Mar | 4.35 | 3,457 | |
| Apr | 3.40 | 2,702 | 118 |
| May | 3.81 | 3,028 | 67 |
| Jun | 4.91 | 3,902 | |
| Jul | 4.17 | 3,314 | 22 |
| Aug | 4.87 | 3,871 | |
| Sep | 4.03 | 3,203 | 40 |
| Oct | 4.14 | 3,290 | 26 |
| Nov | 3.12 | 2,480 | |
| Dec | 4.28 | 3,402 |
Jun is the wettest month (4.91 in, 3,902 gal off the roof); Feb the driest (2.85 in). Garden shortfall is what a 200 sq ft vegetable bed needs beyond the rain that lands on it, April to October.
What size rain barrel for Elkton
Best fit: one 55-gallon barrel, which delivers about 204 gallons to the garden in a normal year (74.4% of its need).
If you set one up, a 55-gallon barrel with a downspout diverter is the whole job. Check that the overflow points away from your foundation, because most of Elkton's roof water will pass straight through it.
| Tank | Water used (gal/yr) | Spills over (gal/yr) |
|---|---|---|
| 55 gal | 204 | 36,143 |
| 110 gal | 204 | 36,143 |
| 165 gal | 204 | 36,143 |
| 275 gal | 204 | 36,143 |
| 550 gal | 204 | 36,143 |
| 1,000 gal | 204 | 36,143 |
| 1,500 gal | 204 | 36,143 |
| 2,500 gal | 204 | 36,143 |
| 5,000 gal | 204 | 36,143 |
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 Maryland?
No statewide rainwater harvesting regulations; check county for local incentives
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