179 lines
9.4 KiB
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179 lines
9.4 KiB
Markdown
---
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layout: post
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title: "Collecting rain, an on-going experiment"
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tags:
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- croyfamilyfarms
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- rain
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---
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My neighbors must surely think that I am some kind of lunatic. Last spring I
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dug up half of the dying sod in the front yard and installed three 8x4 foot
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raised garden beds. Then, last fall, I started banging around with a few, bright blue,
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55 gallon food-grade steel drums, in the car port, which I picked up to catch
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rainfall for my [garden](https://twitter.com/croyfamilyfarms). In this post, I
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will detail my initial results using a home-brew system using these metal
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barrels.
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While Sonoma county is not in drought, and hasn't really been off target
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rainfall in recent years, the concept of catching and storing excess rainwater
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is one which appeals to my "sustainable gardener" ethos. Second to that, I
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strive to be **cheap.** Therefore, if I wanted to store water for use in the
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garden, I needed to find a way to put together a rain collection system for not
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a whole lot of money. I was able to acquire five of these blue barrels
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for _zero_ dollars, quite the steal! Some researching online leads me to believe
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that these barrels may only hold up for two to five years depending on how
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rapidly they rust as the seasons come and go. This motivates another two
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criteria for my rain-collection system: simple and easily replaceable.
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<center>
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<a data-flickr-embed="true" href="https://www.flickr.com/photos/agentdero/31090151421/" title="Fully connected rain barrel assembly"><img src="https://c1.staticflickr.com/6/5484/31090151421_97aaa959dd_z.jpg" width="640" height="480" alt="Fully connected rain barrel assembly"></a>
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</center>
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### Hardware and Design
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The priciest component of the setup is one which I expect to last effectively
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forever, the downspout adapters. These adapters are a thick plastic which
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should survive the elements, and are designed to reduce sending sediment,
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leaves, and other garbage down into my rain barrels, helping keep the barrels
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themselves simple. The cost of the adapters also factored into the design of
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the system. Since they were the most expensive component, I aimed to use as few
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downspouts as possible, and join barrels together into barrel systems which
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could be fed by a single downspout.
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At the top of each barrel is a large threaded hole, roughly 2" in diameter,
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and a narrow 3/4" threaded hole. The 3/4" hole set the standard for sizing
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piping I used to connect everything together.
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Initially I looked at purchasing and fitting a hand-pump to the larger 2"
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threaded hole. There are many hand-pump assemblies which can be purchased but
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the cost was prohibitive, from $30-50 for lower quality plastic pumps, up to
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$200 for durable metal hand-pumps.
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I ended up drilling holes in the sidewall towards the bottom of each barrel
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large enough to insert a 3/4" threaded bushing, which a friend welded into
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place. Be careful when buying drill bits and always wear your safety glasses.
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I sheared the guide bit of one of the circular drill bits when creating the
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holes in the barrels and sent it flying across the workshop. The downside to
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working with steel drums is, as you might expect, steel is _hard_. I drilled
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the holes about 4-5" above the base of the barrel, to allow sediment to settle
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to the bottom without clogging the output valve.
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When my friend finished with the barrels, I set about connecting the different
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barrel systems using the following hardware:
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* A few 10' lengths of Sched 40 3/4" PVC pipe
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* 10 3/4" threaded-to-unthreaded PVC couplers
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* 5 threaded 3/4" plastic ball valves
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* 5 threaded 3/4" metal nipples
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* 2 unthreaded 3/4" plastic ball valves
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* 4 unthreaded 3/4" PVC plugs
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* 6 unthreaded 3/4" PVC T-fittings
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* 2 unthreaded 3/4" PVC 90° elbows
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* 2 large band clamps
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* PVC cement
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I won't dwell too much on the actual pipe fitting, since anybody with a
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measuring tape, hacksaw, and PVC pipe can measure out and connect pipes
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successfully. In my installation there are two "barrel systems," connected to
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two separate downspouts. Each barrel system is connected together through the
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welded bushings (bottom piping, egress), and through the top 3/4" threaded
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hole (top pipeline, inlet).
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The top piping allows water and air to be exchanged as the barrels fill. The
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bottom piping, which is itself independently valved for each barrel, allows
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equal filling of the barrel system and provides the spout for pouring water
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into a watering can.
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The top piping is sealed with PVC cement, except for the inlet pipe which I may
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wish to change the length of later. The bottom piping is also sealed with PVC
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cement, except for the egress pipe which I may wish to change the length of
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later as well.
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The water pressure for the system depends on the "height" of the water stored,
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so each barrel system is also raised on stacked cinder blocks. If you intend on
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raising water barrels, use cinder blocks, or cross-braced 4x4 pieces of wood
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because **water is heavy**. When considering water pressure with such a system,
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it is important to consider the _top_ height of the water, not the height of
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your spigot. When the barrels are full, the water height is about 5', but as
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the water level lowers, the pressure will drop accordingly. Since we're only
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filling watering cans, instead of attaching hoses, this isn't a concern for us.
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But if we were to attach a hose, it would be important that the hose-height
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during use remain below the top-height of the water in the barrels.
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---
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**NOTE**: My first design used brass valves, which look like a normal hose
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spigot, do **not** bother with these. They restrict the water flow, only use
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ball valves which, when turned, allow full use of the pipe diameter.
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---
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Cumulatively, once I experimented with the design, each system took no more
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than 30-45 minutes to assemble, not including curing time for the PVC cement.
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<center>
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<a data-flickr-embed="true" href="https://www.flickr.com/photos/agentdero/33554958431/" title="Northerly rain barrel system"><img src="https://c1.staticflickr.com/3/2861/33554958431_a74a6d9e05_z.jpg" width="640" height="480" alt="Northerly rain barrel system"></a>
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</center>
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### Mistakes Made
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Of course, I made some mistakes in this experiment, many of which can be
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corrected as soon as the barrels are emptied for the season.
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* The downspout near the "south crop" receives the water from almost the entire
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backside of the roof and can fill in less than a couple hours during a steady
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rain storm. I want to add more capacity to that side of the house, which would
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likely require re-orienting the barrel system.
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* The barrels shouldn't be sitting level but should slope slightly to allow air
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to push up through the exposed 3/4" threaded hole in the top where water
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enters. Currently, two of the barrels are leveled incorrectly and air gets
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trapped as the barrels fill with water. Unfortunately this air must be manually
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allowed out, by unscrewing the plug in the larger hole, in order for those
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barrels to fill entirely.
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* The downspout chosen for the "north crop" receives an adequate amount of output
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and also rapidly fills during a steady rain. But the water requirements for the
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north crop, which receives 12+ hours of sun during the summer, will far outpace
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supply. Although I am experimenting with better water conservation techniques
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for the north crop this summer such as: rice straw covering. oolas, and
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better timing for sporadic deep waterings, I will definitely serve the north
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crop the entire summer with water from the rain barrels.
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* The lip of the barrels should be shielded from the rain with a roof of some
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form, as water can collect in the tops of the barrels and sit stagnate for
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mosquitoes or rust.
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After the 2017 season has depleted the rain barrels, I expect to spent a
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weekend inspecting, reconfiguring, and improving the system, but that will have
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to wait until all that heavy water is gone.
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### Conclusion
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The most significant conclusion that I can draw from this experiment, and the
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data I have collected, is that my wife is **incredibly** tolerant to my
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nonsense. Bright blue 55-gallon steel drums aren't the most inconspicuous
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addition to our yard, but it seems that my idiotic excitement at barrels full
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of water wins her over.
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A more practical conclusion is that this project has been worth it, for no other
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reason than making me really consider my **water budget** for the season. I
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know for a fact that I will not reach September without depleting all 275
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gallons of stored water. That's okay, the water is there to be used, but I'm
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considering how much water different plants, soil types, and plot locations
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need.
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Another conclusion to take away from the first year of this experiment is that
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**cost is king.** When I first scoped out rain barrels, some vendors in the
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area, including our local recycler, were charging $25-35 **just for one
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barrel.** I'm not aging fine wine in these barrels, I'm storing dirty water
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which rolled down off my roof. While I didn't keep detailed receipts on this
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system, I estimate that I spent less than **$100** total. Considering the cost
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of water, with this cheap of a system, I am still unlikely to break even unless
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the system is usable for 5+ years, which I doubt will happen. In spite of any
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financial incentive, the rain water is unfiltered, and also not chlorinated,
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which I expect to be better for the overall plant and soil health. Only time
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will tell however.
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Although the system is small, it's preventing 275 gallons of drinking water
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from being used for agriculture, and at the end of the day (for $100) that
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makes me feel good.
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