A Green way of using rainwater with the convenience of city water. The attached solar regenerated pump enables you to water plants with pressure, even when the water in the barrels falls low enough that it barely passes the level of the faucet. The sun-warmed water also aids in the growing of plants as it does not shock them. The twin 85 gallon barrels are raised onto a very sturdy 4x4 box assembly from recycled wood, held together with new carriage bolts because the total weight of all the water when full is approx 1700lbs. This frame is resting on eight 2 inch thick 18 inch square cement pads to prevent sinking. The barrels are raised to increase the head pressure and decrease the work load on the pump.
Vote for me if you think my idea is worth passing on to show people being green doesn't have to mean sacrificing quality or convenience . Thank you for taking the time to look at my instructable!

Step 1: Water Supplied From Mother Nature

link barrel to downspout. ensure top of barrel remains below level of water entry. I found the Watersaver attachment for the 3x4 downspout pipe works perfectly. In order to enable adequate water flow to the barrel I adapted the Watersaver attachment by drilling out the side and adding a flange for a 1inch PVC fitting. I sealed this by using a rubber gasket and additionally using a silicone sealer. Ensure there is a downward slope between the downspout and the barrel entry.

Step 2: Overflow Back to the Downspout

ensure you have a complete path for water from the downspout to the barrel or barrels then from the overflow to the downspout again.
1" pvc overflow line from last barrel back to downspout. ensure you maintain a drain angle towards the downspout or sediment could collect in the line.

Step 3: Downspout Drain Connection

1" pvc entry back into downspout. ensure pvc pipe does not fully block 2"x3" downspout and keep the downward slope to the pipe to make the water flow towards the downspout.

Step 4: Manifold

common connection point for using water.
this photo of the manifold is before I put the water gauge on. (shown on intro and last step)

Step 5: Water Filter

filter the water from the barrel to protect the pump. keeps the roof sediment from wearing out the pump. This water filter will last forever, as it has a reusable nylon mesh filter inside, that only requires periodic rinsing.

Step 6: Battery Box With Power Switch

keeping the battery and pump protected from the elements inside a full size battery case .

Step 7: Inside View of Battery Box With Motor

An inside view of the standard size battery case and equipment layout. the solar cell was left with clamp connections in order to enable quick removal of the battery case lid for cleaning and maintenance.
The pump was recycled from an older sailboat. The battery is a standard size lawn tractor 12v, and with proper maintenance should last 6-10 years before being needing to be recycled at the depot.
An older car battery that just doesn't have the power to crank the car fast anymore would be more than adequate for this application, and a great alternative to buying a new battery.
The 5.5W solar cell was also recycled for a fraction of it's original cost from an online classified, and solar cells have a lifespan of aprox 15-20 years. I wanted this little project to last as long as possible before needing any repairs.

Step 8: Flowjet Pump

closeup of Flojet 4405-143 pump particulars
another pump that I have seen that is almost identical to this is made by shurflo
This type of pump is used in RV's or sailboats to supply water pressure, as well as for using as a wash down pump on boats.
I chose this type because it had an internal pressure switch that stopped it from running all the time, only turning on when the water pressure in the hose drops. In addition I got a super deal on it secondhand.
There are many different styles of pump available that will be more than adequate for this application. It depends on your budget, and availability of secondhand pumps in your area.
Other things to consider would be whether or not you want the pump running all the time (lawn sprinkler) or only when you press the trigger on your hose nozzle. Without a built-in pressure switch, the pump would run all the time as soon as you turned on power. In all types of applications, make sure the pump output pressure does not exceed the pressure rating of your hose/pipe or you might burst it if the outlet was closed or blocked unexpectedly.

Step 9: Water Gauge

As the water level changes inside the barrel the level inside the tube will follow the same level.
This was fun to install as I didn't want to waste all the nice rainwater and drain the tank before I drilled a 3/4" hole in the bottom of the tank to install the angled shut-off valve. Reminded myself to only use a battery powered drill :)
I reused some 1/2 inch plastic tubing that I had left over from another application and connected it to a 3/4 inch angle valve with a shut off (which came in handy during install)
I sealed around and under all penetrations into the barrel (valve and screws) with a two part epoxy that was a water proof filler and sealer.
It is important to not completely seal the tube or the level will not change to reflect the level in the barrel.