Rainwater Basics:
On a 1000 square foot structure, you can collect 600 gallons of water from a 1" rain event.
Over the course of year, many clients could collect 30,000 or more gallons of rainwater.
Plants love rainwater.  It picks up nitrogen as it falls to the earth and does not have any harsh chemicals or salts.
Design Ideas:
300 Gallon Tank on a Stand
300 Gallon Rainwater Cistern on Stand
Downspout feeds into a basket

Basket Close Up - leave a gap between the downspout and the basket.

First Flush Diverter
 There is a cap at the bottom of the righthand pipe with a small hole in it.  Water will drain naturally, but remove the cap occasionally to flush out leaves and debris.  When it starts raining, leaves and debris will fill the right hand pipe.  When the water reaches the "T" it will feed into the system.
Below are some tips hopefully making it easier for you design your rainwater system.  No two systems are exactly alike and often there are multiple ways to achieve the same goal!
    - Pre-Design
    - Design
    - Installation
    - Purchasing
  • What are going to use the water for?  Tank size is often determined by what you want to use the water for. We can use 70% of our water on irrigation!  
  • How much can you collect?  Most people are shocked to learn how much water they can collect.  In Central Texas, where we get about 32" of rain in a normal year, a one story 2000 square foot house can collect 35,000 gallons of rainwater a year.  Don't design a system that tries to direct that much rain into a 300 gallon tank!
  • How much space do you have?  Lots of times space is a limiting factor.  Are there trees that prevent installation of large tanks?  How high are the eaves on your house?  Seven foot tall tanks work well for eight foot eaves.  Is there a fence in the way?  We've temporarily removed fencing to get tanks into place.
  • Are you applying for a rebate?  Many municipalities offer rebates from $0.50 / gallon up to $1.00 / gallon.  In some instances you need to be pre-approved before you purchase and install your tank.
  • Are you part of an HOA or POA?  Great news!  In 2013 the Texas Legislature passed a law prohibiting HOA's from banning rainwater harvesting systems.  They might limit the location, but they must allow rainwater tanks.  If your HOA is unfamiliar with this law, tell them to see Texas Property Code Sec 202.007.
  • Sizing the tank:  A one inch rain collects 600 gallons per 1000 square feet of covered space (roof).  Rule of thumb: plan for aRainwater Tank with First Flush Diverter 2" rain event.  Therefore if you are collecting off of 500 square feet, that will produce 300 gallons on a 1" rain.  Therefore  500 gallon or larger tank would be appropriate.  For larger surface areas, consider using multiple tanks.
  • Size the inlet and overflow: If your tank is 1000 gallons or less, you are probably only collecting from one downspout.  In that case a 3" inlet is probably fine.  If you have 6" gutters you might want to go with a 4" inlet.  If you have multiple downspouts, you can still go with 3" PVC piping, but at some point expand to 4" and have a 4" inlet.  Rule of thumb: match the overflow size to the inlet size.
  • Choose an outlet size: If you are just going to attach a garden hose, go with a 3/4" bulkhead connection.  That will allow you to screw in a spigot.
  • Pump or no pump: Many people want to pressurize the water to be able to pump into the house or run an irrigation system.  Within city limits pressurized systems need backflow protection devices.  Another option is to buy a submersible sump pump.
  • Keeping debris out of your tank:  If your gutters clog with leaves your tank will clog will leaves if you just run it directly into the tank.  Gutters screens are your first line of defense.  You may also choose to use a basket on the tank.If neither of those options are doable, a first flush diverter is recommended.
Installing Your System:
  • The tank needs to be installed on a solid base.  We recommend crushed granite or a similar base.  The simplest thing to do is get some treated landscape timbers and form a square about a foot wider than your tank.  Fill with 2" - 3" of crushed granite and tamp down.  The tank can sit directly on the crushed granite.  Of course, a concrete pad also works!  Keep in mind water weighs 8.3 pounds per gallon, so a 2500 gallon tank weighs over 10 tons when full!
  • Moving the tank into place:  Large tanks slide easily across 2 X 4's.  Tanks can also be tipped on a bottom edge and rolled.  Do not lay a large tank on its side and roll it!
  • Positioning of fittings:  Generally do not position the overflow above the outlet.  If you decide to plumb the overflow, the pvc pipe will come down where your outlet is!  The overflow should channel water away from the tank and house towards a low lying area.
  • Bulkhead connectors: Important!!! These are threaded on both the inside and outside.  You will only be able to screw things into the inside of the bulkhead!  The outside threads are reversed thread and only accept the locknut.  Therefore a 3/4" bulkhead accepts a 3/4" spigot, for example.
  • Painting the PVC:  Choose a metallic gray spray paint to make the overflow and inlet look like metal.  Rustoleum (TM) makes a good product available at The Home Depot.
  • Securing the top:  The top of your tank needs to be secured in place so it doesn't blow off.  Four self tapping sheet metal screws should be included with your tank.  We recommend pre-drilling the holes about an 1 1/2" from the edge.  There is a lip  at the top of the tank.
Purchasing Your Tank:
  • Lead times are 3 - 4 weeks.
  • A 50% deposit will get you in the production schedule.
  • We accept cash, checks, and credit cards.  We will email you an invoice and you can pay online through a secure transaction portal.
  • We do not need the tank inlet/outlet form with your order as that is the last step in the process, but the sooner the better!
  • We will contact you when the tank is ready to schedule pick up or delivery.  Saturdays are always an option but we need to plan for it!
  • We use a third party for shipping logistics.  They pick up the tank at our factory, palletize it and ship it with insurance.  Tanks over 7' tall cannot be shipped.  Shipping can add one to three weeks.
Questions?  Need more help?  Call or email!