The New Water Wise Irrigation Drop-By-Drop

This Section will cover the steps you need to take in the field to collect the information you'll need to design or retrofit your system properly.  In Resources I've included a checklist for you to use while collecting your field data.

Sprinklers, either spray or drip systems, need hydraulic pressure to operate properly.  In this short lecture I'll discuss the importance of proper pressure for your system.

Many of you will be on a water meter and paying a utility water bill.  So, how do you calculate how much water is available when you are on a meter?  In this lesson we'll cover that topic and the way you can get this information when you only have a static water pressure reading.

How do you know how much pressure or gallons per minute you have available?  In this lecture I'll show a couple of ways to determine these critical factors.  If you are on a private well there is an explanation of how to determine you GPM in Resources.

Now that you have the hydraulic information you need it's time to do some simple mapping of your property so you know what areas you may want to plant -whether it's lawn or shrub beds.  By mapping and actually doing a simple design/layout of turf or shrub bed areas you'll be able to plan your new irrigation system more accurately and write up a parts list for when you go shopping.  In this lecture I'll explain a simple method to mapping your site.

Using the techniques I covered in Lecture 9, try mapping all or part of your property.  Maybe it's just a lawn or shrub bed, maybe it's your whole back yard.  Regardless, this is an important step in creating an efficient irrigation system.

We've covered a lot of ground in this section.  In this last lecture of the Section I'll do a quick recap of what we've learned so far.

In this Section I'll cover how to draw your plan to scale, how to read a manufacturer's catalog (and why it's important!) and how to select the best irrigation for your situation - either spray or drip systems.  We'll also cover sprinkler layout for when you want to use spray or rotors.  In Resources I've provided links to irrigation catalogs by both Hunter and RainBird Irrigation.  These are two of the most popular and available brands but all manufacturers will have this info online if you Google it.  Also a PDF on how to read a scale rule is available for download.

Throughout the course I've used the architects scale since that's what is used in the United States, however many of you will be designing in metric scale.  So, here it is, how to use the metric scale in design - how to read it and what does this 1:50 or 1:100 mean....

With your site survey in hand we'll now review the steps to draw a scaled drawing of your site.  I'll be explaining this using imperial (feet & inches) measurements but the overall technique is the same for those of you using metric tape measures and metric scale rules.

Sprinkler selection is an important aspect to efficient irrigation.  A good rule of thumb is to use spray for lawns and very low ground covers and drip irrigation for shrub beds where growing plants can block spray heads.  Trees should be irrigated separately from lawns and shrubs - they need their own system.   In this lecture we'll look at different types of sprinklers and where they might be best used in the landscape.

In this lecture we'll start laying out sprinkler locations for a lawn area.  For this we'll be using a landscape plan I developed for a client and you can work along with me as I select and place sprinklers for the turf.  In this exercise I'll be using RainBird PRS pop-up sprinklers with MPR Spray Fixed Arc Nozzles.  In Resources you can download a copy of the blank Site Plan we'll be using.  There are two sheets of plans for download.  One is full size at 24" x 36" with a scale of 1/8" = 1' 0" and one is size A3 metric with a scale of 1:100 - both are of the same plan.  There is a link to the RainBird Irrigation Catalog in the resources section of Lecture 12. 

A completed Irrigation Plan using this site is available for download in Lecture 27.  The size of the paper for this download is both 24" x 36" and 11" x 17".

As we've seen, sprinkler selection can be somewhat subjective.  The goal is to choose the best sprinkler for the situation, place it for minimal overspray and always shoot for head-to-head coverage.  Better to have sprinklers that throw too far than not far enough, leading to dry spots and dead plants or lawn.  In our next Section I'll be discussing drip irrigation in the landscape.

Drip, or Micro Irrigation, is by far the most efficient way to irrigate your shrub beds and even your vegetable gardens.  In this Section we'll look at what different components make up a drip system, we'll discuss individual emitters vs. inline drip and how to design your system so that it works properly.  At the end of this Section you'll be much more comfortable designing and installing your own drip irrigation!

In this Lecture I'll cover the basic components of a drip irrigation system.

Both Point-Source (individual emitters at the plant) and inline drip (where the emitters are built into the 1/2" drip line) have their place in the landscape.  In this Lecture I'll discuss where I feel each application is best used in your garden.

While drip irrigation is very efficient you can do even better by knowing the texture of your soil - the percentage of Sand, Silt and Clay.  The texture will have a direct effect on how water moves and is held within the soil in your garden.  In this short lesson I'll show you how to do a simple jar test that will reveal your soil texture!

Designing your drip system is more than just laying it out on the ground and turning on the water.  Because drip irrigation works on a lower gallon or liter per minute flow rate hydraulics play a vital role.  In Resources you'll find some guidelines for choosing emitter and line spacing options based on the soil texture and slope of your property.  Also, you'll find a Soil Infiltration Rate Table - this is useful information to help you manage your irrigation runtimes to prevent runoff.

A quick overview of what we covered in this Section.

After designing our irrigation we need to balance the gallons (liters) per minute of water available for each valve.  In this section we'll look at how to calculate all of these factors so our system operates properly.

Spray and rotor sprinklers will use the most water per minute of operation.  We need to be sure of how to add up the water being applied compared to the water (GPM) available.  This lecture will give direction so that we don't exceed our design capacity.

While spray systems operate on gallons (or liters) per minute, drip systems are calculated in gallons (or liters) per hour.  In this lecture I'll cover the basics for calculating your water usage for both point-source drip irrigation and inline drip irrigation.

Valves work based on hydraulic principles - mainly GPM and PSI.  When selecting an irrigation valve for your project you want to be sure it will operate within the flow and pressure rates available.  In this lesson we'll look at how to determine these parameters using the manufacturer's catalog.

Being sure that the irrigation pipe is the correct diameter is critical to proper system operation.  Pipe that is too small in diameter for the flow of water will exhibit greater pressure loss through friction as the water moves through the pvc.  In this Lecture I'll go over how to correctly size your pvc piping for optimal performance. 

Knowing what your gallons (or liters) per minute flow rate is is critical to your sectioning your irrigation into separate zones that will operate properly and not overtax the system.  Keeping plants with similar water needs grouped together will also aid in efficient irrigation. In this last Lecture of this section we'll have a quick recap of what we've covered.

I recently had a very old (35 years old!) inline valve fail.  In this lecture you'll see the process I went through to replace and upgrade my old installation

Very often you won't have a lot of room when replacing inline valves.  Roots, hard soil, irrigation pipe, all get in the way!  In this video I'll show some options to explore when you find your workspace is cramped...

Wiring your irrigation valves is pretty straight forward.  One solenoid wire is attached to your "hot" wire (some call this the Signal Wire) that is attached to the station terminal inside the irrigation controller.  The second solenoid wire is tied to the "Common" wire that is connected to the Common (COM) terminal inside the controller.  The common wire is looped throughout your irrigation valves to create a continuous circuit when the valves are activated through the controller. 

So many times I've opened valve boxes only to find them full of dirt that a gopher or other rodent has chosen to  push into the void.  In this video I'll show what I've been doing now for years that really does help to keep your valves being buried in soil.

We've covered a lot of ground as far as designing your irrigation, but it still has to go in the ground.  in this Section I'll go over some basics and offer some tips for when it come to installing your new system.

The POC - Point of Connection - is where you finally tie in to your existing water source thus feeding water into your irrigation mainline.  Ideally you will only have one POC - this allows you to control the irrigation separately from your household water.  Even if you use irrigation water, having one POC is much more convenient and manageable.

Once you've done the wiring at the valves you still need to connect to your irrigation controller.  In this video we'll look at the inside of a controller and how to connect the wires for automatic operation.

Sometimes you just want to change out your existing spray system to a more efficient drip irrigation system.  There are a couple of ways to do this that aren't expensive and are very effective.  In this video we'll look at two ways I retrofitted two of my valves from spray to drip irrigation.

A quick wrap up of this Section and one final tip - get yourself a Soil Moisture Probe. It will help you to manage your irrigation more efficiently as you'll be able to measure how wet or dry your soil is.  As you get to know your garden yu'll have a much better idea of when and how long to run your new, efficient irrigation system!