Of the 100,000 litres of water used, approximately 40 per cent is used outdoors. One of the easiest ways to save thousands of litres of water around the home is to reduce the water used on landscapes. An efficient irrigation system can play an enormous role in contributing to these savings. Importantly, conservation techniques in the garden save not only water but money, time and effort as well as benefiting the natural environment.
It is widely accepted from this outdoor water use, up to 50 per cent is wasted from inefficient irrigation systems alone. With water costs primarily on the increase from most of the main water retailers in Australia, this creates immediate economic impacts to any business or homeowner as well as longer sustainable impacts in the future.
With populations increasing and water not being an infinite resource, we need to start becoming smarter with our outdoor water use if we wish to preserve our long-held entitlements such as:
- Social benefits that can include mental health and well being, physical health, safe playing areas, surfaces and socialising.
- Environmental benefits such as lower air temperatures, better air quality, plant-soil-water balance, conservative water use, pollution entrapment and less run-off due to over-watering.
- Economic benefits such as reduced maintenance costs, lower water cost, less time to manage irrigation sites and reduced plant replacement cost.
Did you know that 97 per cent of water on the earth is saltwater, with only three per cent being potable, and only per cent of it accessible as the other two per cent is captured within the ice caps?
One of the main components to the anatomy of an irrigation system is the controller, and whilst the term has been used for many years in the irrigation industry, the name is a little skewed. We have to ask ourselves does the controller really control the irrigation or is it really just a simple timer that a contractor, landscape maintenance team or property manager has programmed to start and stop at pre-determined times to what they think is an acceptable quantity of water to maintain that landscape?
A true controller actually ‘controls’ that irrigation rate of water that is needed for that part of the landscape or open space either based on what has happened in terms of weather or what is going to happen or a combination of both. It therefore becomes "smart."
There's more to smart technology than this, so we can't automatically define this as a smart controller. I believe there is a difference that is sometimes confused or glossed over by creative marketing departments in their endeavour to simplify the message.
We have smart meters, smart phones, smart TVs, smart fridges, smart pyjamas, smart watches...the list is becoming longer and longer each day. The one common link to these is connectivity via wif-fi, sim, or Ethernet with the ability to send and receive data or instructions either automatically or when we want or need. Simply adding this function to a timer does not instantly turn this timer into a smart controller.
There are a number of features this controller must have on top of that ability to simply connect directly to the user via their smart phone, tablet or personal computer. Here is a list of water management or irrigation scheduling items prior to simply adding the ability to communicate remotely through one of the above portals:
- Weather stations for receiving daily high and low temperatures plus rainfall data as a minimum requirement with additional inputs such as solar radiation, wind, humidity and dew point to assist in improving accuracy. These units have come down in cost and can be installed on the actual site for accuracy or using the connected smart technology to a number of weather websites. Whilst these may have a higher accuracy in terms of the data, they lose their accuracy if the actual weather station is simply too far away for the actual irrigation site.
- Input for the type of sprinkler or emitter that is used on that irrigated site. The controller must be able to incorporate this data for the individual solenoid valves or zones that are required when irrigating. This determines when the irrigation is operating how much water is being applied and what rate. This is typically in millimetres per hour.
- Input for the type of plant used on that irrigated site, once again by solenoid valve or zone allowing the system to determine whether that plant type requires little to no water in order to actively grow or higher amounts of water. Such examples may be native trees and shrubs for little water or annuals, cool season turf requiring a higher water use.
- Input for determining the soil type and the slope of that particular area of irrigation. Soil types have different infiltration rates, and when used in conjunction with the above sprinkler rate of application, you can ensure the water is applied in a manner that will allow the water to absorb into the soil profile as opposed to ponding or puddling on the surface or running off down the slope.
The above inputs allow the controllers to take the data and work out for each solenoid valve evapotranspiration (ET) being a combination of evaporation and transpiration. These inputs are more important on a controller prior to adding the ability to just remotely access a timer. To improve the capacity and add further smarts to the above ‘must haves’ we can then add some of the below to particularly allow the landscape maintenance (LM) teams and irrigation water management to monitor far more efficiently multiple controllers over wide geographic.
- Connection to web-based software for the LM to easily access from smart phone, tablet or PC anywhere anytime to make the necessary programming changes or react quicker by using functions such as rain delay of impending rainfall forecast. The key here is web-based and not computer software driven to ensure continual updates.
- Flow sensors to determine a data log of water used plus the ability to determine by solenoid or zone a high flow or low flow event such as a broken sprinkler head or burst pipe. It is important to isolate this issue automatically as well as inform the LM of the problem via email.
- Web-based software ensures the ability to create a range of reports to ensure the system is working correctly, who is using the system, to show water saving reports to analyse the data in order to make better more refined water management decisions on the hope to saving more water.
We irrigate our landscapes trying to ensure the correct amount of water at given point of time, for a given plant type on a given soil type with a given sprinkler type with the objective of applying enough water to have a healthy attractive looking landscapes.
Most professionals are able to achieve this when they are there by visual inspection. However, as we become more and more time poor, there is an ever growing list of smart controllers to choose from to help automate this decision on a daily basis as opposed to maybe weekly, fortnightly, bi-annual or unfortunately just once a year.
Most of us have seen the effects of under-watering, but even over-watering can have negative effects with continual run-off, staining of kerbs, pathways, building damage though ground movement and - as important to the plant - killing them with kindness.
As homeowners, landscapers, building property owners that care about sustainability, the health of their landscapes for the stakeholders that use them and reducing costs we can use the smart technology that exists and will continue to evolve through building management systems and building automation systems driving and maintaining the fundamentals of good irrigation scheduling.