By Sean Fleming, Master Gardener Volunteer
What are water quality and water conservation, and why do they matter?
Water conservation is using water efficiently, so less needs to be drawn from rivers, lakes, reservoirs, and aquifers. Water quality is about keeping pollutants out of all those major water sources, as well as smaller water bodies like backyard creeks and ponds.
If we use water efficiently, your water bill is lower, there’s less need to build additional water supply infrastructure, and more water is left in lakes and rivers for the ecosystems that need it and for people to enjoy recreationally. And for groundwater, it reduces the likelihood of drawing down your well to the point that you and your neighbors run out of water. More broadly, lack of abundant clean water deeply affects not only fish, but also birds, mammals, forests, and beneficial insects – and of course people and pets. We all live downstream, and someone else’s pollution can wind up coming out of your kitchen faucet.
How can gardeners contribute?
Gardeners interact with, and affect, the landscape and the water cycle more than many folks do. Here are some important general steps you can take:
- Use water-wise plants and natural landscaping. Native plants are usually a good bet, because they generally don’t require irrigation. Many non-native plants work too, if you pick the right ones. Mulching and composting help by retaining water and decreasing evaporation. Landscape design is important too – rain gardens are one example that helps water quality.
- Water efficiently. Providing gardens with more water than they need is wasteful and expensive, of course, but it also triggers erosion and runoff of sediment and chemicals. It can even wash fertilizer out of the root zone of your crops. Use drip irrigation or water plants directly instead of sprinklers where possible, and optimize your sprinkler system so it evenly distributes the right amount of water. It usually gives you a better garden too!
- Be judicious with your selection and use of fertilizers, pesticides, and other natural and non-natural chemicals. Many of these things will wind up in natural water bodies. Even overuse of organic fertilizers can be a huge water quality problem, contributing to algal blooms in lakes and oceans for example.
- Be mindful of your non-gardening choices too. Get rid of pharmaceuticals, paint, and other household chemicals by disposing them at the appropriate recycling and disposal center, for example, and use water-efficient fixtures and appliances.
Does this really make a difference?
Yes! These may seem like small things, and individually they are – but when you add them up across the whole country and over the years, they really add up.
In fact, water quality and conservation is, overall, an environmental success story. Some estimates suggest that total national water use has remained at about 1970s levels due to efficiency improvements. And in many industrial areas, water quality is much better now than it was a few decades ago. The days of rivers literally catching fire – this actually happened to the Cuyahoga River in Ohio, which was polluted with flammable chemicals – are thankfully over.
That said, there are major challenges looming, especially in the West, where a combination of relatively dry climate and tremendous population growth are severely pressuring our water resources, natural ecosystems, and water supply infrastructure. Even here in Benton County with our soggy winters, the natural summer drought period requires careful water management, especially as the regional population and economy grow, increasing water demand. Plus, more people generally means more pollution. Each of us can do our part to mitigate those impacts going forward.
How does the water cycle work?
But how does your garden plot fit into the big scheme of things? How can your choices contribute to – or contribute to solving – water conservation or quality problems? The answer lies with the water cycle.
The world’s water is all connected in a big loop. Water evaporates from crops, forests, lakes, seas, and oceans; it’s transported hundreds or thousands of miles in the atmosphere, through storm systems and the jet stream for example; it falls as rain or snow, contributing in turn to glaciers, groundwater aquifers, lakes, and ultimately rivers; and it then flows back to the ocean.
Your garden is a step in that journey, and the water passing through kind of “remembers” what it saw there. As rain falls on your vegetable patch, chemicals you’ve added will dissolve and then be transported as runoff, or downward to aquifers, and either way can wind up in a creek, which flows into a bigger stream, which joins with a big river, and so forth.
Plus, withdrawals from rivers and reservoirs for water supplies, like watering your vegetable garden, collectively add up to a huge modification of that natural cycle. The change is often destructive. For example, dams on the Columbia River for water supplies, flood control, and hydropower generation have destroyed salmon migration patterns and habitat availability. In extreme cases, like the Colorado River, so much water is taken out for human use that the river no longer makes it to the sea.
Practical information resources for gardeners
Here are some great places to look for information about specific things you can do to improve water quality and conservation in your own garden:
- General tips about water conservation in dry western Oregon summers.
- 7 basic steps for creating and maintaining water-efficient landscapes.
- How to build a rain garden.
- Quick guide to 10 low-water perennials that thrive in dry situations.
- How to design and maintain a water-efficient landscape.
- A gardener’s guide to protecting water quality.
- Irrigation, groundwater quality, and crop production.
- Detailed guide to water-efficient plants for the Willamette Valley.