It takes a significant amount of water to create energy. Likewise, it takes a significant amount of energy to extract, move and treat water.
U.S. power plants withdraw 143 billion gallons of fresh water every day. That’s more than the amount withdrawn for irrigation and three times as much as is used for public water supplies.
Water and Electricity
When we think of water and electricity, hydropower is usually the first thing that comes to mind. But power plants that use coal, oil, nuclear energy or natural gas are also water-dependent.
By burning coal or natural gas (or by maintaining a fission reaction), these power plants generate heat. The heat is then used to boil water, produce steam, and turn turbines. Much of the water used by these plants is needed to cool the steam they generate.
Withdrawal vs. Consumption
In order to better understand how much water is used by power plants, we must first define some terms.
Water “use” by power plants comes in two forms: withdrawal and consumption. Withdrawal refers to the amount of water a power plant extracts from a lake, river, aquifer, or other water source. Power plants that use “once-through cooling” technology withdraw large volumes of water a single time. They then discharge it directly to waste.
Withdrawal is important for several reasons:
Water intake systems can trap aquatic wildlife
Water withdrawn for cooling (but not consumed) is returned to the environment heated, potentially harming wildlife
Power plants that tap groundwater for cooling can deplete aquifers.
Consumption refers to the water that evaporates in the cooling process. Consumption reduces the amount of water available for other uses, such as sustaining ecosystems. Plants that use “recirculating cooling” technology tend to have lower rates of water withdrawal, but consume much more of that water through evaporation.
So How Much Water Do Power Plants Use?
A 2013 report published in Environmental Research Letters found that, in the year analyzed (2008), U.S. power plants:
Withdrew some 50 trillion gallons of water
Consumed 1.6 trillion gallons of that water
Used freshwater (non-ocean) sources for 86 percent of those water withdrawals and 96 percent of the water they consumed.
This means that about 100 billion gallons of freshwater is withdrawn daily and several billion gallons consumed.
How does this compare with our other water needs, say, agriculture?
When it comes to withdrawals, power plants are number one. According to the most recent available data provided by U.S. Geological Survey, the power sector is responsible for more than 40 percent of freshwater withdrawals.
On the consumption side, agriculture is the biggest user. (Much of the water used to irrigate fields doesn’t make it back out.)
What Can Be Done?
As climate change continues to affect precipitation and temperature patterns across the country, water-dependent energy production could be inhibited.
There are several ways we can address the water-related impacts of energy use:
Designing appliances, buildings, and vehicles to be more energy efficient. This is the simplest and most cost-effective solution. The less energy used, the less water required.
Retrofitting old coal or nuclear power plants with more water-efficient cooling systems. According to scientists, this could potentially double water consumption, but could reduce water withdrawals to a mere fraction of current use.
Encouraging (i.e., incentivizing) the expansion of renewable technologies (such as wind and solar energy) that require no water usage.
December 3-7 at the Long Beach Convention
and Entertainment Center
Irrigation Show 2018 is the only national trade show designed specifically for irrigation professionals.
It’s where the irrigation industry comes together to network, learn and promote irrigation. (Did you know it’s also the world’s biggestirrigation trade show?)
Register by Nov. 1 to save on education classes, full registration and exhibits. Discount housing is also open, and attendees can book their hotel online.
To download the Irrigation Association’s 24-page Registration Brochure, click here.
More than 4,000 distributors, dealers, contractors, consultants and growers are expected to attend this year’s event in Long Beach, California. You’ll have the opportunity to:
Check out new and innovative products, technologies and services.
Explore new suppliers.
Learn about the latest business trends and irrigation best practices.
Network with current business partners and with industry leaders who share the Ohio IA’s commitment to efficient irrigation.
New This Year: Radio Row
Radio Row is a dedicated space for radio stations and podcasts from across the country to provide live broadcasts and interviews with irrigation professionals and experts attending the Irrigation Show. See some of your favorite ag radio and podcast hosts live and in action.
Extended Floor Hours
This year, show floor hours have been extended to 10:00 a.m. to 5:00 p.m. on Wednesday, Dec. 5, and 10:30 a.m. to 3:30 p.m. on Thursday, Dec. 6.
Educational Opportunities
You can discover great ideas, learn new skills and earn CEUs with some of the industry’s most experienced professionals. Landscape irrigation topics for educational classes at this year’s Irrigation Show include:
Pumps and Soils
Landscape Irrigation Design
Advanced Irrigation Wiring Methods
Hydraulic Troubleshooting
Alternative Water for Landscape Irrigation
Landscape Drip Irrigation Design
Two-Wire Technology Systems for Landscapes
The Business of Landscape Irrigation Contracting
One-hour seminars will provide detailed coverage on a focused topic in landscape irrigation. Seminars are open to all attendees with a full registration. Participants will earn 1.00 CEU for each hour. This year’s topics will include:
Weather-Based Irrigation Controllers
Low-Impact Development and Irrigation
Impacts of Irrigation in Building Rating Systems
Using Drones to Improve Irrigation Management
Certification Exams
Exams for the following certification programs will also be available at this year’s Irrigation Show:
But by grouping together plants with similar water needs, homeowners can improve their irrigation system’s efficiency, avoiding both overwatering and underwatering. With hydrozoning, the plantings that require less water are situated farther from the water source.
The Hydrozone Plan
When creating hydrozones, you first want to identify the specific water requirements for individual plantings. (Information on water needs can be found through your local extension service.)
Wherever possible, consider replacing high-maintenance plants with native plants that would naturally require less water.
Once water needs of plants are identified, you’ll want to create four categories for watering: Routine Irrigation, Reduced Irrigation, Limited Irrigation and No Irrigation. When labeling your zones, consider not only types of plants in that area, but also element exposure.
For example, areas that receive direct sunlight will require more water than those located in shade. Similarly, for plantings situated at the top or bottom of a slope, you’ll need to account for runoff and accumulation.
Let’s take a look at each of the four zones.
Zone 1: Routine Irrigation.
This is the area that requires the most water. It’s the highest-maintenance hydrozone, and typically encompasses turf grasses, particularly in high-traffic areas such as playgrounds. (Other areas of your lawn may be zoned differently, and even allowed to go dormant or semi-dormant during dry spells.)
Early morning is considered the best time to water a lawn, with less chance for evaporation and wind loss. Conversely, try not to water your lawn late in the evening; the grass will stay wet all night, and become more susceptible to disease. When watering a lawn, be sure to wet the soil to a depth of 4 to 6 inches.
This zone can also include any water-loving trees and shrubs you may have, such as eastern red cedar or elderberry bushes.
Zone 2: Reduced Irrigation
Zone 2 generally includes areas that are used less for activity, such as shrub and flower beds located near the main entrance of a home.
The amount of water this zone requires depends on the maturity of the plants, amount of direct sunlight received, and depth of mulch.
The soil here should remain somewhat moist, not crumbly dry and not dripping wet. You want to make sure these plants receive enough water to thoroughly replenish the plant’s moisture. (Hint: After watering, the soil should feel like a damp paper towel.)
Zone 3: Limited Irrigation
This is a minimal hydrozone, for areas of your landscape requiring little irrigation. It may include buffer zones between homes, road verges (strips of vegetation between the sidewalk and street) and embankments.
This zone is an ideal location for native plants that will survive primarily on rainfall, with just occasional irrigation to enhance the plants’ health. The Ohio Department of Natural Resources can offer plenty of suggestions.
Zone 4: No Irrigation
The last hydrozone is reserved for areas that require no supplementary water supply. This could include utility areas, mulched parkways, and naturally existing vegetation or xeriscapes.
When hydrozoning, keep in mind the ways in which the various areas are used. Lush “oases” or higher water-use zones are often located closer to the house, while more natural areas with low water needs are placed at the back or edges of the property.
Your hydrozoning plan may take a bit of tweaking and modification, but it will eventually result in an environmentally friendly and thriving landscape.
Along with that intense summer heat comes the prospect of drought. Which means we may have to make some agonizing decisions regarding which plants in our yards and gardens to save and which plants to let go. For some of us, that can be like having to make a “Sophie’s Choice.”
So before the need for these difficult decisions becomes a reality, there are some things we can do to make the most of the water that will be available.
The Importance of Mulch
Did you know that more than 50 percent of the water applied to bare soil is lost through evaporation? Of course, the rate of that evaporation increases with higher air temperatures, solar radiation and wind. But applying mulch in landscape and garden beds can help to recoup almost all of that moisture loss, depending on the type of mulch used. (Added bonus: Mulch helpskeep the plant roots cool.)
For landscape plants and perennial flower beds, for instance, gardening expertsrecommend applying shredded bark or wood-chip mulches on top of bare soil at a depth of 3-4 inches. Surprisingly, however, these same wood-chip mulches should not be used in vegetable gardens and annual flower beds. Why? Because when decomposing, they cause soil microbes to deplete the soil’s nitrogen reserves. This makes the much-needed nitrogen unavailable for use by the garden plants.
Organic Composts
With vegetable gardens and annual beds (or wherever the soil is regularly tilled or disturbed), organic mulches that break down more quickly are advisable. These would include well-rotted compost, animal manure, lawn/yard clippings and any combination of these.
To increase the effectiveness of grass or compost mulches, try this:
Place one to two moistened sheets of newspaper on top of the soil, slightly overlapping the sheets
Cover the newspaper with a layer of compost mulch.
Allow the newspaper to decay over the growing season.
Till the decayed paper into the soil, along with the top layer of mulch.
What About Rocks?
Rock mulches should generally be avoided around landscape plants. During the day, the rocks will absorb heat and then radiate that heat back at nighttime. This increases both the heat stress and water needs of plants. In particular, white and other light-colored rock reflects light back onto plants, compounding the heat stress felt by plants during times of drought.
More Drought-Related Tips
Here are a few more guidelines to keep in mind when navigating through a seasonal drought:
Do not fertilize. All fertilizers contain salts that will rob the plants of much-need moisture in the soil. Wait until your plants have fully recovered from the effects of drought before fertilizing. (Plants experiencing drought conditions often appear wilted and droopy because they’re saving their energy.)
Do not prune during or immediately following a drought. To do so would place too much stress on the plants. and send them into shock.
Apply water slowly and deeply to the soil. The best way to maintain your garden is through drip irrigation or soaker hoses that apply water directly to the soil above the root zone. Placing these hoses under two to three inches of mulch helps retain soil moisture.
Hold off on watering until after sundown to reduce evaporative water losses.
July is the peak month for water consumption in the U.S., which is why every July the Irrigation Association uses its national platform to promote smart irrigation practices and technologies.
First launched in 2005, this national campaign continues to gain traction each year as consumers and irrigation specialists alike recognize the positive impact efficient irrigation and water use provides to all of us.
Smart Systems
Among the strategies being presented to consumers, first and foremost is proper programming of automatic watering or sprinkler systems to deliver just the right amount of water at the right time.
Additional strategies include:
Proper landscaping, keeping soil healthy, mulching and routine landscape maintenance
Investing in an irrigation system that uses the best, most flexible, components; has “smart” controls; and meets code requirements (See related article, “Wi-Fi-Based IrrigationTechnology Explained.”)
Watering during the evening and early morning to prevent evaporation, taking soil type and sprinkler placement into consideration
Maintaining the sprinkler system regularly by adjusting sprinkler heads, repairing leaks and monitoring pressure
WaterSense
According to the EPA’s WaterSensewebsite, adopting water-savvy habits also is essential to maintaining and extending our communities’ water supplies, especially during peak use. WaterSense partners with manufacturers, retailers/distributors, and utilities to bring high-performing, water-efficient products to the marketplace.
WaterSense also partners with professional certifying organizations to promote water–efficient landscape irrigation practices. Since the program began in 2006, WaterSense has helped consumers save a total of 1.5 trillion gallons of water, resulting inmore than $32.6 billion in water and energy bill savings.
Take the Tuna Can Test!
Place a few empty tuna cans randomly around your lawn, with some cans close to the sprinkler head and others several feet away. Turn on your system and measure how much time it takes your sprinkler to fill the cans with a half inch of water. Then, try watering for that amount of time twice a week. Gauge how your landscape responds, and adjust based on weather conditions.
Alternatively, you can simplify this system by replacing your standard clock timer controller with a WaterSense-labeled irrigation controller.
Get On Board
Here are just a few of the many “Smart Ideas” irrigation professional can use to promote SmartIrrigationMonth:
Add the SmartIrrigationMonthlogo to your website, ads, customer presentations, field signs, invoices and more.
Submit a press release or letter to the editor of your local newspaper.
Ask employees to add the SmartIrrigationMonth logo to their e-mail signature block.
Host a live demonstration of water-saving irrigation technologies, in the field or at your location.
Feature water-efficient products and services in displays, ads, promotions and product demos with the SmartIrrigationMonth logo.
Use a banner, outside signage or counter sign to encourage customers to ask about smartirrigation.
Make smartirrigation the theme of sales calls.
Give awards to customers and/or business partners who promote water-efficient practices.
Volunteer to speak to a local homeowner association, garden club or civic group.
Water “use” by power plants comes in two forms: withdrawal and consumption. Withdrawal refers to the amount of water a power plant extracts from a lake, river, aquifer, or other water source. Power plants that use “once-through cooling” technology withdraw large volumes of water a single time. They then discharge it directly to waste.
There are several ways we can address the water-related impacts of energy use:
Extended Floor Hours
Early morning is considered the best time to water a lawn, with less chance for evaporation and wind loss. Conversely, try not to water your lawn late in the evening; the grass will stay wet all night, and become more susceptible to disease. When watering a lawn, be sure to wet the soil to a depth of 4 to 6 inches.
Do not prune during or immediately following a drought. To do so would place too much stress on the plants. and send them into shock.
Alternatively, you can simplify this system by replacing your standard clock timer controller with a WaterSense-labeled 
