Rain barrel diverter diversions

It turned out that deciding how to get the water into the barrel was a major issue.

There are two main issues:

• Open or sealed barrel system?  A sealed barrel system uses watertight connections everywhere.  An open barrel system usually has water entering through the open top of a barrel.
• Diverter or open barrel top?  Should water enter the system through the top of a barrel, or through a tube from a diverter?

There are many kinds of downspout diverters available.  After wading through the characteristics of many, it became apparent that there were a few different types:

• Offset diverters - usually a Y-shaped downspout with a lever for manually selecting whether to send all the water to the water barrel or down to the ground through the rest of the vertical downspout (or a new replacement for the rest of the downspout).
• Automatic diverters with automatic overflow.  A single tube goes to the rain barrel.  The barrel must be of the sealed type, so when the barrel is full the tube will fill with water and all water will then go down the downspout.  There is one exception to the "sealed type" rule: If the barrel is connected to the diverter through the side of the barrel, an automatic diverter which is installed at the same height as the barrel's opening can work.
• Diverter and overflow tubes.  One tube goes from the diverter to the rain barrel, and an overflow tube comes from the rain barrel to the downspout.  If the overflow tube is below the level of the rain barrel's overflow, this can work with an open barrel system.

Decision: Open barrel system

I wanted to keep the intake both simple and allow maximum capture.  So I decided to simply cut the downspouts above the level of the barrel and put in new elbows, directing the water away from the house and toward the open top of the barrel.  All the water will be aimed at the barrel, and I'll deal with the overflow in the barrel and on top of it.

That means that I will use a design where there is a wide opening in the top of the barrel.  So it will be an open barrel system instead of a sealed barrel system.  The exact aiming of the downspout can be adjusted by adding a short length of downspout, or a short flexible downspout extension.

Catching rain water is against the law - ksl.com

Oh, great. Utah requires a "valid water right" in order for you to use rain water that falls on your property. I'm glad I'm not in Utah.

Catching rain water is against the law - ksl.com

How much water can I collect?

I want to use rainwater in my garden, but how much might I get?  Will one 55 gallon barrel be more than enough, or can I expect more water than that?

Calculating how much water is available

The formula for calculating how much water my roof will collect is:

[ Collection area (in square feet) x 144 (square inches per foot) x Rainfall (inches of rain water depth) ] / 231 (cubic inches per gallon) = Gallons of water

Those square feet are based on flat land, so the slope of my roof doesn't matter.  With a house that's about 50 feet by 30 feet, that's 216,000 square inches.  If I capture all of a one-inch rainfall that's 931 gallons.  Okay, so one inch of rain is a lot of water.

How much rain can I expect?

I'm in Minnesota, and the average rainfall during each month of the growing season (April - October) is:

2.06   3.06   4.17   3.95   3.69   2.91   2.29

That's 22.13 inches total, divided over 7 months is a little over 3 inches a month, so there's about one inch of rainfall every 10 days.

931 gallons every 10 days.  That does seem useful.  At a minimum I can keep the dry flower box damp.

Average rainfall for each state

You can find your state's average rainfall in the table below, which came from the NOAA.  This is a rough estimate, as many states have wetter and drier areas.

Total Precipitation in inches by month
 Climatology by state based on climate division data: 1971-2000
  
   State           Jan    Feb    Mar    Apr    May    Jun    Jul    Aug    Sep    Oct    Nov    Dec    Total
Alabama            5.91   5.18   6.65   4.77   4.69   4.59   5.39   3.90   4.26   3.16   4.79   5.01   58.28
Arizona            1.30   1.25   1.35   0.54   0.42   0.31   1.74   2.09   1.30   1.20   0.97   1.13   13.61
Arkansas           3.65   3.61   4.93   4.82   5.20   4.31   3.52   2.87   3.72   4.08   5.34   4.72   50.78
California         4.14   3.95   3.55   1.40   0.83   0.32   0.19   0.30   0.58   1.20   2.63   3.11   22.20
Colorado           0.79   0.75   1.29   1.47   1.92   1.44   2.01   1.95   1.35   1.20   1.03   0.77   15.97
Connecticut        4.30   3.23   4.42   4.30   4.33   4.05   4.19   4.39   4.36   4.31   4.42   4.08   50.39
Delaware           3.92   3.10   4.34   3.51   4.18   3.52   4.05   4.63   4.19   3.38   3.31   3.55   45.68
Florida            3.61   3.17   4.13   2.84   3.92   6.94   7.19   7.26   6.39   3.46   2.88   2.76   54.57
Georgia            5.20   4.49   5.28   3.62   3.58   4.44   5.05   4.66   3.89   3.01   3.55   3.94   50.72
Idaho              2.12   1.72   1.73   1.56   1.97   1.51   0.92   0.84   1.08   1.30   2.07   2.14   18.96
Illinois           1.97   1.99   3.22   3.83   4.31   4.12   3.94   3.69   3.24   2.87   3.41   2.74   39.32
Indiana            2.44   2.31   3.40   3.96   4.47   4.25   4.20   3.88   3.18   2.92   3.62   3.09   41.72
Iowa               0.95   0.98   2.20   3.33   4.23   4.62   4.27   4.18   3.40   2.51   2.13   1.24   34.05
Kansas             0.77   0.91   2.25   2.59   4.18   3.88   3.61   3.16   2.68   2.18   1.73   0.98   28.92
Kentucky           3.77   3.77   4.60   4.19   5.05   4.34   4.47   3.71   3.49   3.13   4.09   4.38   48.98
Louisiana          5.91   4.66   5.32   4.89   5.46   5.20   5.15   4.47   4.55   4.05   5.06   5.38   60.09
Maine              3.46   2.52   3.37   3.46   3.64   3.77   3.74   3.61   3.68   3.70   3.82   3.51   42.28
Maryland           3.66   3.03   4.09   3.43   4.27   3.80   4.11   4.01   4.04   3.38   3.41   3.41   44.64
Massachusetts      4.17   3.34   4.16   4.11   3.91   3.84   3.83   4.02   3.94   4.16   4.35   4.05   47.88
Michigan           2.02   1.45   2.22   2.69   2.94   3.23   3.15   3.58   3.65   2.85   2.77   2.28   32.84
Minnesota          0.86   0.64   1.45   2.06   3.06   4.17   3.95   3.69   2.91   2.29   1.58   0.77   27.44
Mississippi        5.92   4.96   6.30   5.61   5.39   4.47   4.80   3.67   3.81   3.45   5.19   5.64   59.23
Missouri           1.95   2.15   3.51   4.04   4.82   4.26   3.96   3.58   3.97   3.36   3.82   2.81   42.23
Montana            0.80   0.60   0.90   1.30   2.34   2.40   1.65   1.35   1.33   1.05   0.86   0.80   15.37
Nebraska           0.51   0.60   1.66   2.38   3.75   3.45   3.27   2.63   2.10   1.56   1.16   0.57   23.63
Nevada             0.96   0.92   1.09   0.76   1.01   0.63   0.51   0.63   0.71   0.75   0.81   0.76    9.54
New Hampshire      3.42   2.62   3.37   3.50   3.76   3.85   3.94   3.97   3.66   3.95   3.93   3.44   43.42
New Jersey         3.94   2.96   4.18   3.93   4.28   3.77   4.46   4.57   4.14   3.51   3.70   3.71   47.15
New Mexico         0.67   0.60   0.71   0.63   1.11   1.23   2.27   2.64   1.82   1.34   0.83   0.78   14.63
New York           2.99   2.41   3.12   3.42   3.68   4.00   3.81   3.86   4.14   3.48   3.74   3.24   41.90
North Carolina     4.51   3.71   4.67   3.47   4.28   4.40   5.04   4.97   4.78   3.61   3.45   3.57   50.45
North Dakota       0.50   0.45   0.80   1.40   2.31   3.19   2.75   2.10   1.74   1.41   0.73   0.44   17.82
Ohio               2.51   2.27   3.06   3.47   4.06   4.10   4.09   3.77   3.10   2.62   3.16   2.93   39.16
Oklahoma           1.48   1.78   3.07   3.32   5.13   4.24   2.73   2.75   3.80   3.39   2.79   2.05   36.55
Oregon             3.79   3.16   2.93   2.18   1.88   1.27   0.62   0.73   1.07   1.90   3.97   4.06   27.55
Pennsylvania       3.04   2.58   3.41   3.55   4.07   4.45   4.15   3.78   4.08   3.18   3.58   3.16   43.02
Rhode Island       4.45   3.63   4.65   4.32   3.72   3.52   3.20   3.99   3.80   3.79   4.55   4.36   47.98
South Carolina     4.70   3.79   4.64   3.16   3.69   4.72   5.05   5.29   4.51   3.42   3.21   3.67   49.84
South Dakota       0.45   0.53   1.30   2.11   3.10   3.24   2.75   2.13   1.66   1.62   0.82   0.44   20.14
Tennessee          4.65   4.31   5.60   4.51   5.33   4.48   4.67   3.52   3.88   3.32   4.77   5.18   54.22
Texas              1.59   1.67   1.85   2.14   3.52   3.35   2.22   2.54   3.19   2.95   2.02   1.84   28.87
Utah               1.05   0.99   1.21   1.07   1.20   0.64   0.88   1.01   1.07   1.30   0.99   0.82   12.26
Vermont            3.11   2.33   3.07   3.28   3.84   3.93   4.21   4.49   3.97   3.67   3.73   3.19   42.82
Virginia           3.64   3.13   4.04   3.42   4.26   3.79   4.34   3.84   4.00   3.50   3.29   3.15   44.39
Washington         5.38   4.37   3.76   2.71   2.23   1.77   1.02   1.05   1.65   3.05   5.85   5.93   38.78
West Virginia      3.46   3.11   3.97   3.62   4.57   4.23   4.75   4.13   3.51   3.05   3.46   3.43   45.30
Wisconsin          1.22   1.00   1.96   2.86   3.37   4.02   4.07   4.27   3.74   2.50   2.29   1.35   32.64
Wyoming            0.63   0.57   0.86   1.36   2.06   1.58   1.33   1.02   1.14   1.04   0.76   0.62   12.97
  
 Calculated at NOAA-CIRES CDC based on data obtained from NCDC

RainPerfect Rain Barrel Pump

I'll revisit pumping later, but before I forget I'll mention that I just noticed the RainPerfect solar-powered rain barrel pump.  It has a battery to store the electric power from its solar cells, able to power pumping of up to 100 gallons at 13 psi.

The design requires that the control box with the battery and pump (actually I suspect the pump is inside the barrel) are to be mounted on top of a barrel, providing a compact package where the hose is attached.  A pipe under the control box extends down into the barrel.  This can be a problem for a single rain barrel with an opening on the top, but would work on a barrel with a hose intake or on one of the overflow barrels of a multibarrel installation.

More at: RainPerfect™ Rain Barrel Pump by Rule

Rain water safety

I know that urban rainwater is considered to not be potable, but I did consider whether to use it on my few vegetable plants.  I decided not to use it on my tomatoes and other veggies.

Dust and ash (from incinerators and coal power plants) are one source of contamination.  During a dry period, windblown dust accumulates on roofs.  Ash accumulates year-round, depending upon wind direction from the incinerator or power plant.  Minerals and toxins from those can be reduced by not collecting the first rain after winter or after a dry spell.

However, bird droppings and squirrel droppings can't be avoided so easily.  I could test for minerals and toxins to learn what my water is like, but bird droppings are a more random source and I never know when a flock of something will pass by.

I'm not yet interested in adding filters suitable for removing bacterial contamination, so I'll use potable water for the vegetables.  I don't have many of those anyway.  The flowers are thirstier, so they'll get the rainwater.

Almost-free water

I have a small garden area and a flower box that have trouble staying green.  There is sand under the topsoil, so I started by adding more organic matter to the dirt so it would retain water better.  But it's a shame to run the sprinkler every few days when we tend to get rain once a week.  So I started looking at collecting the rain water so I can make use of it.

As we all do, I have limited funds, so I want to spend as little as possible.