Landscaping for Water Conservation: A Permaculture Perspective
When the rains slow and the heat arrives in the Pacific Northwest, smart watering and landscaping strategies can really make a difference in the health of your plants, your water bill, and your yard’s impact on the larger goals of water conservation. Wildlife and pollinators can also struggle to access moisture, and our backyard water strategies can help them conserve their energy for their important work by providing easy water sources. Lastly, summer is the time of vacations, outings, and visitors, so it’s important to have smart solutions in place for getting water to your garden even when you are out of town or busy having summer fun. Let’s discuss landscaping for water conservation from a permaculture perspective so you can save time, money, and waste of our fresh water resources during the dry months of summer.
Table of Contents
Why Water Conservation Matters
Permaculture Concepts For Water Conservation
Landscaping For Water Conservation
Supporting Wildlife + Pollinators Through Water Features
Why Water Conservation Matters (Even in the rainy Pacific Northwest)
Water is an important finite resource, and its dwindling supply can have huge impacts on our ecosystems and human populations. Globally, water scarcity is a growing crisis creating a lack of water for drinking, sanitation, agriculture, and healthy ecosystems. Although 71% of the Earth's surface is covered with water, the oceans hold approximately 96.5% of Earth's water. Only 3% of the planet's water is freshwater, and only 1.2% of freshwater can be used for drinking. According to the United Nations, over 40% of the global population currently experiences water shortages, and this figure is expected to grow in the coming years. Fresh, clean drinking water is one of the most limited resources on the planet, and sustainable access to water will be one of the defining issues of our time.
In the United States, the average water footprint (including both household use and the amount of water used to produce the goods and services we use) is over 1800 gallons per person every day! Many of us, especially in developed parts of the world and areas like the rainy Pacific Northwest, can take the availability of water for granted as we make choices in our homes and landscapes. Unfortunately, such significant daily water consumption is not sustainable over time. If you are interested in learning about your water footprint, there are calculators online to understand the full impact on water resources of our lifestyle choices, including household water use as well as water use that occurs in the process of providing goods and services we utilize.
The Pacific Northwest is known for being a wet, rainy place, so is it really something homeowners need to pay attention to in our climate?
In fact, even with its rainy reputation, the Puget Sound region ranks only 56th in the nation in average rainfall. Rainfall varies greatly across the Pacific Northwest. For example, Seattle ranks 32nd among the 50 largest US cities for rainfall, with much of the region's rain instead falling in particular areas of the state (such as the Olympic Peninsula). More importantly, WHEN we get the rain is as important as how much we get. The PNW has a Mediterranean climate. Therefore, it gets lots of precipitation from Fall through Spring, but very little in the summer, when demand is the highest. Most of our region’s water is stored in the annual snowpack on surrounding mountains. Even when there is a good snow pack, by the end of the summer, our region experiences low levels in our streams, reservoirs, and groundwater. At this point in the year, the water needs of people and their landscapes compete with those of migrating salmon, other wildlife, and vegetation. This leads to increased fire risk, stress on our already suffering salmon populations and all the food chains they nourish, and decreasing water quality as quantity decreases.
With climate change, scientists are predicting warmer temperatures leading to less snowpack and more rain during the rainy season, resulting in less stored water for use during warmer months. Combining lower snowpack, drier summers, and increasing populations, water suppliers are already predicting they could have insufficient supply to meet demand.
If we all get in the habit of using water-efficient behavior every day, we can help ensure that there’s enough water for our communities, businesses, and the environment. Specifically, landscaping is a large source of water use in the home environment. On average, residential landscapes may use about 50-70% of household water during peak summer months. However, this is also an area where we can make a significant impact in our water use by creating water-conscious landscapes.
Permaculture Concepts for Water Conservation
The ethics of permaculture — care for the earth and care for people — guides us to use water thoughtfully and return it to the system without contaminants after our use. The ethic of fair share asks us to limit our consumption in order to leave enough clean water for others, including our animal and plant neighbors.
The general motto in permaculture when it comes to water is “slow it, spread it, sink it” with the addition in some cases of “store it, share it”. Basically, permaculture thinking is looking for ways to catch the water as close as possible to where it falls, hold it on-site for use as many times as possible, and then return the water (without contaminants) back into the ground to replenish our aquifers, rivers, and lakes. The goal is to make the path that water takes to exit the system as long as possible.
These concepts have been implemented throughout history, as can be seen in the water-wise methods of the rice terraces of the Philippines, rain collection ponds in Peru, the tassa method of farming in Africa, and the Aztec Chinampas (floating gardens). However, this motto of “slow it, spread it, sink it” was coined in the late 90’s by Brock Dolman and has become widespread among water conservation advice for homeowners, businesses, and government policies. In Brock’s own words: “When I began working in urban stormwater management and low-impact development, I brought the perceptual design method worldview of permaculture. Permaculture is a method of how to create regenerative and socially just systems that are based on natural patterns and processes. So when I was looking at stormwater management and green infrastructure, we used those tools—the principles of protracted observation, stacking functions, relative location, planned redundancy, and using onsite resources. These are permaculture design principles. They apply to everything we do.”
When it comes to storing water, most think of rain barrels catching water from house gutters or a system of water tanks and cisterns. These are great options to consider for a landscape. However, there are also many other ways to store or slow water that can work at any scale without a lot of added infrastructure.
Store water in soil. Soil is by far the largest reservoir of water on the landscape, and increasing the soil’s water-holding capacity is the cheapest option among water storage options. We can increase water storage by:
Building up the level of organic matter in the soil, which improves its ability to hold water.
Increasing the amount of vegetation on the land to cover soil and reduce evaporation.
Creating earthworks, like swales and basins, that can increase infiltration and recharge the shallow groundwater.
Store water in vegetation. Thick vegetation can create a large reservoir of water storage on the leaves and branches, and in the living biomass of the plants (which are 90 percent water by weight). The interaction between established deeply rooted plants and fungi in healthy soil systems allows for an amazing network of water redistribution, allowing the whole plant ecosystem to thrive even under dry drought conditions.
Store water in the ground. Small changes in topography, like swales and basins, can catch water and help it infiltrate the ground. Small basins filled with organic mulch, like wood chips, can catch and hold water at individual plants or plant groupings. Leverage points like home roofs can be identified to intercept water early in its flow and direct it where it is needed or an area where it will soak in slowly, like a rain garden or pond.
Landscaping for Water Conservation
Here are ways that you can implement these broader permaculture water management concepts in your yard.
Reduce your lawn
Lawns not only require a huge amount of water (and often water pollutants) to maintain, but also take up space that could be serving a better water storage system. Grass that is mowed short for a manicured lawn results in short roots and compact soil, which, as outlined above, leads to quicker runoff and less infiltration of precious rainwater. Allowing grass to grow long or transitioning it to a native meadow or a larger native perennial planting will promote deeper roots that can draw water from deeper in the soil and redistribute it to the upper soil horizons. In turn, this will create a healthy soil network and a highly effective soil sponge for holding water.
Choose native plants and group plants by microclimate
Native plants that are adapted to the rain and climate conditions of your local area and the specific location (microclimate) where you plant them will always thrive best without extensive watering. Choose drought-resistant plants if you are planting far from a natural water source. Choose water-loving plants where there is already a natural water source. Group plants that have similar water needs together so that if watering is needed at certain times of year, you can adjust your irrigation or hand watering to each area’s specific needs.
Plant densely and use ground covers and mulches
Bare soil leads to water evaporation and run-off. This loss of moisture is greatly reduced when soil is covered by plants or wood chip mulch. Mulches, ground covers, cover crops, and generally dense plantings also contribute to soil building and protect the soil web at the soil surface from the harsh elements, further improving the ability of the soil to hold water. It’s especially important to plant on sloped areas where deep-rooted and shallow-rooted groundcover species can be utilized to stabilize the soil and reduce water runoff and erosion.
Improve Soil
Soil that is deep, not compacted, and high in organic matter (full of broken-down and decomposed plants and animals) will hold large amounts of water. Basically, you want your soil to act as a sponge to allow water to soak in and stay for a long time rather than running off the surface or draining quickly out of your landscape. Improving soil means adding organic matter like compost and mulch to the soil, focusing on growing deeper and more diverse roots to feed the soil web, loosening compacted soil with calcium amendments like lime or gypsum, and keeping soil covered from the elements. Other methods to explore for creating soil that retains water include adding biochar or planting into Hugelkultur beds.
Reduce impermeable surfaces or use them to direct water consciously.
Impermeable driveways and pathways (just like compacted soil!) do not let rainwater infiltrate the earth, leading to increased evaporation loss, runoff, and water build-up where it is not useful. Either convert impermeable surfaces to permeable ones or use the impermeable surfaces to direct water to a rain garden or other well-designed water catchment system.
Rain barrels, tanks, and cisterns
One impermeable surface that is useful in directing water where you need it is a roof. A chicken coop roof can direct water into a chicken waterer, a greenhouse roof can lead rain into a water trough for filling a watering can, and a home roof can collect water in barrels for watering the landscape plants. There are easy-to-assemble small to large-scale rain catchment systems available on the market that help homeowners capture and store water and then direct it where they need it. However, even a bucket under a downspout that directs water to your favorite plants rather than a mud puddle by your driveway is a low-tech example of a water conservation mindset. Take water from where it is abundant to where it is scarce. Store water in the rainy season to use in the drier months.
Smart Irrigation and Watering Strategies
It's believed that about 50% of outdoor watering is lost to evaporation, wind, and runoff that results from inefficient irrigation systems and methods. Compared to sprinklers, a well-designed drip irrigation system reduces runoff waste and evaporation. In gardens and smaller planting schemes, small-scale methods of slow and water-wise irrigation might be used. These include, for example, the use of clay pot Ollas that allow water to slowly seep out into the soil around plant roots as needed. Wicking beds are another water-wise option, which involves creating raised beds with a reservoir of water at the base. Water is drawn up through the growing medium above through capillary action, providing water for plants growing in the bed.
Grey Water Filtration Landscaping
Permaculture helps us make connections between nature, our gardens, and our homes. Designs can be about more than just food production or gardening. For example, grey water from sinks and washing machines in our homes can be filtered for use in irrigation through plant-based filtration systems, or reed beds.
Earthworks
Adjusting the land’s topography to capture and direct water has been used worldwide throughout history. This can be simple acts of moving earth with a shovel to create depressions and channels, or can be large-scale earth moving with machinery to set up your landscape for optimal water dispersal and infiltration. All of the following water conservation earthworks can be explored at any scale.
On-Contour Swales and Berms are level channels created across a more gentle slope that help to prevent runoff and erosion, slowing and capturing runoff and facilitating its infiltration into the soil. The berm is the mound on either side of the swale. The swale (wetter) and berm (drier) are then planted with appropriate plants. Another form of swale that might be used in a permaculture design is a bioswale, or vegetated swale, typically planted with species that help to filter water from stormwater and runoff.
Check dams are also commonly added along drainage channels or bioswales that slow the course of the water through the system, increasing the amount of water infiltrated into the ground.
Terracing can be used on slopes too steep for a swale. They slow the flow of water downhill and increase infiltration, and can provide level areas for growing.
Infiltration basins or sunken gardens lower than the surrounding soil level are sometimes incorporated into a design to catch water within the landscape.
Keyline designs identify ridges and valleys in topography to construct interconnecting channels, ponds, and earthworks to spread out water flow and optimize infiltration of rainfall. This more technical earthworks method and planting scheme is used to reduce erosion, prevent floods, improve soil, mitigate drought, and move water from waterlogged areas to drier areas.
Rain gardens are specific types of infiltration basins, into which rainwater harvested from a home roof or paved areas is directed. These are planted with native plants that can tolerate wet and dry conditions as rainfall fluctuates throughout the year.
Eco-Ponds, Wetlands, and Bog Gardens are different ecosystems that can hold water in the landscape and serve as a habitat for plants that like wet or waterlogged conditions, as well as aquatic and marginal pond species.
Supporting Wildlife & Pollinators through Water Features
Besides “slow it, spread it, sink it”, some add the “share it” to the motto of ethical water use. In our urbanizing landscapes, our wildlife and pollinator friends have fewer freshwater sources in their home landscapes. Our landscaping choices can add features that offer up watering opportunities for our non-human friends. Whether it’s a small frog pond, creek water feature, bird bath fountain, larger-scale eco-pond, or simply bee waterers scattered throughout your gardens, you can make life a little easier for these hardworking members of our ecosystem while also holding water in your landscape and recycling water for multiple uses.
-
Irrigation timers are the modern way to keep your garden watered while you are busy or out of town. They can be hooked up to drip irrigation as well as sprinklers. However, if you have a smaller space like a raised bed or pot that does not have irrigation, try an Olla watering pot to keep your garden moist for up to a week. This watering method, which has been used across cultures throughout history, involves an unglazed clay vessel buried in the soil within two feet of the plants so that it slowly releases water to the soil as it dries out.
-
Lawn: 5 AM and 5 PM, 6 days per week with one off day for the mowing day. Run times will vary depending on the type of irrigation heads and nozzles being used.
Vegetable/annual flower gardens: 30-45 minutes, 3-4 times per week with drip irrigation and varying run times for other types of overhead watering (extra if very hot or new transplants/seedlings). Water daily for seed germination.
Newer perennial plantings: 45 minutes of drip irrigation every day with one day off per week. To avoid transplant shock during the first 8 weeks from planting, run drip every day plus additional hand watering as needed.
Established perennial plantings: 45 minutes, 3-4 times per week in the summer drought period.
-
Blacklotus recommends 4-6 inches of screened arborist wood chips to retain moisture, reduce weeds, and add to soil building as they decompose over time. Depending on the application, living mulches ( low-growing drought-tolerant plants and ground covers such as clovers, Irish moss, thyme and other herbs, sedums, comfrey, bulbs, lettuces, root vegetables, vining vegetables, etc) are also something to be explored as a cover for soil between your larger perennial plantings.
-
Some options to consider as a replacement for your lawn include:
Drought-tolerant eco-lawn or pollinator meadow
Native trees, bushes, and ground covers (see native drought-resistant plant list below)
There are many seed mixes to choose from and instructions for ecolawns, prairies, and pollinator meadows available at these two local seed companies:
Be sure to select a mix native to your area to avoid spreading invasive species.
-
Sedums
Sedum oreganum. Oregon stonecrop.
Sedum divergens. Cascade spreading stonecrop
Broadleaf stonecrop (Sedum spathulifolium)
Grasses
Karl Foerster
Hakonecholoa macra
Festuca glauca -blue fescue
Miscanthus sinensis
Trees
Western red cedar (Thuja plicata).
Bitter cherry (Prunus emarginata).
Pacific madrone (Arbutus menziesii).
Oregon white oak (Quercus garryana).
Ponderosa pine, Willamette Valley form (Pinus ponderosa).
Shrubs
Blueblossom (Ceanothus thyrsiflorus).
Red flowering currant (Ribes sanguineum).
Red osier dogwood (Cornus sericea).
Blue elderberry (Sambucus mexicana).
Red elderberry (Sambucus racemosa).
Evergreen huckleberry (Vaccinium ovatum).
Hairy manzanita (Arctostaphylos columbiana).
Mock orange (Philadelphus lewisii).
Oceanspray (Holodiscus discolor).
Oregon grape (Berberis nervosa).
Tall Oregon grape (Berberis aquifolium).
Nootka rose (Rosa nutkana).
Western serviceberry (Amelanchier alnifolia).
Wavy-leaved silk-tassel (Garrya elliptica).
Groundcovers
Kinnikinnick (Arctostaphylos uva-ursi).
Coastal strawberry (Fragaria chiloensis).
Wild strawberry (Fragaria virginiana).
Woods strawberry (Fragaria vesca).
Herbs and ferns
Douglas aster (Aster subspicatus).
Blue-eyed grass (Sisyrinchium bellum).
Camas (Camassia sp.).
Western red columbine (Aquilegia formosa).
Goldenrod (Solidago sp.).
Douglas iris (Iris douglasiana).
Oregon iris (Iris tenax).
Oregon sunshine (Eriophyllum lanatum).
Pearly everlasting (Anaphalis margaritacea).
Cascade penstemon (Penstemon serrulatus).
Sword fern (Polystichum munitum)
Salvia dorrii - purple sage
Yarrow (Achillea millefolium).
Annuals
California poppy (Eschscholzia californica).
Farewell-to-spring (Clarkia amoena).
Globe gilia (Gilia capitata).
Final Thoughts
The design of your home landscape is always a place where you have the opportunity to embody your values and take action to support the health of your families, your communities, and your planet. This is definitely true when it comes to water conservation since our backyards often represent a large part of our water consumption. There are many worthwhile ways to contribute to water conservation in your landscape, so you can choose which elements work for your lifestyle, aesthetic, space, and budget. Many of these shifts will also lower your water bill, save you time, and beautify your yard at the same time. For any larger projects in which you would like assistance, Blacklotus has the permaculture-based design skills, installation team, and tools to make your water-conscious landscape a reality with you.
