With water becoming a scarce natural resource across our country, water conservation has become a driving design force in the landscape industry. There are many benefits, both for us and our society, that can be seen by adopting water-wise practices in residential and commercial landscapes. Water conservation not only preserves this precious resource but also helps prevent water pollution to our local water supplies. As a landscape architect, these principles are used in my designs to be mindful of our common goal: responsible stewardship of the land.
Water conservation can be defined as the practice of using and managing water and water sources efficiently to reduce unnecessary water usage and evaporation. With that in mind, there are many strategies that landscape architects and designers can adopt to further water conservation in their projects. Let's explore a few of them:
1. Limit turf area:
Since turf areas are one of the biggest culprits in the water wars, reducing those areas will improve conservation significantly. Many homeowners still demand large turf areas, so education should be the first goal in communicating with those customers. Designers should also try to incorporate turf only in areas where dogs and kids will need it. Plan to naturalize the rest of your landscape and let these less demanding landscapes dominate your design. If you must use turf, choose wisely. Fescue turf tends to use an enormous amount of water to keep it lush and green as opposed to other turfgrass varieties. If your customer cannot live without turf, then move to a turf variety that requires less water such as Bermuda or zoysia.
2. Improve soils:
Amend soils generously with rich organic material when planting. Organic soil amendments can include peat moss, wood chips, grass clippings, straw or manure. There are commercial soil amendment products that encourage water retention. These amendments will allow a broader root system on the plants. Better soils allow more natural aeration, drainage and natural water holding capacity of the soil. Amendments also encourage the water's ability to be infiltrated into the ground and prevent runoff. For the designer, adding a specification detailing your suggested soil mix to your plans would be helpful for landscapers to follow when implementing your designs.
3. Mulch all planting beds with a water-retaining mulch:
Mulch forms a protective layer between the plant's roots and the air, encouraging water retention. Most forms of mulch such as shredded hardwood or pine needles retain moisture at the root system of the plants. This is necessary not only for the plant's health but also to keep water from evaporating into the atmosphere. For hot and dry climates, avoid rock or mulch that retains or radiates heat. This type of bed covering can not only burn the plants in summer but will also create a hot and dry microclimate in the area.
4. Introduce a rain garden in runoff areas:
In a low spot of a design area, rain gardens can be a great solution to capturing and cleaning groundwater before infiltration. While dry most of the time, rain gardens only tend to hold water after a rainfall. Designers can utilize native shrubs, perennials and flowers in these areas to create a beautiful and functional landscape bed.
5. Use other methods to capture water:
Many practices utilize the ability to capture runoff or “gray water” to be used and replaced back into the landscape. Some suggested methods are rain barrels, cisterns and even using porous paving. These methods will capture runoff water and, with the use of a pump, can allow that water to be used for irrigation purposes.
6. Use native and drought-resistant plants in the landscape:
Native plants and other drought-tolerant species will naturally use less water than their counterparts. Many drought-tolerant plants are staples at local nurseries. Designers can also check with their local cooperative extension office for lists of drought-tolerant plants in their areas.
7. Group plants according to their water needs:
Designers can divide their plant material choices into water use zones, grouping each according to their water needs. This grouping will assist in the most efficient watering schedule for your customers. Avoid use of high water requiring plant materials. Additionally, designers can add watering specifications to their plans for their customers to follow.
8. Irrigate and water responsibly:
Traditional irrigation practices, which use spray heads to water plant material from overhead, are an inefficient method of watering, especially in bed areas. Spray irrigation also causes evaporation of water before it even reaches the plant material. In areas where natural rainfall is not enough for good plant health, drip irrigation waters plants directly at the root. Unlike spray heads, which encourage evaporation, drip irrigation is an efficient and water-wise way to irrigate. Also, ensure that hoses have shut off nozzles. This will prevent leaks and unnecessary water use.
9. Cover pools:
Encourage your customers to cover their pools to prevent water evaporation. Swimming pools tend to lose an inch or more of water each week due to evaporation. Having your customers cover their pools can save them money and pool water each season.
10. Pressure wash less:
When your crew is cleaning up at a jobsite, have them use a broom to loosen dirt and debris. Once that is complete, only use the pressure washer for a short time to do the final cleaning.
Examples of water-wise practices in design:
In the designs pictured, many water-wise practices were integrated into this backyard to maximize water conservation: rain barrels, funneling runoff from the site into a cistern for irrigation purposes, drip irrigation, drought-tolerant plants and reducing turf areas.
In the example to the right, a low spot of the yard incorporates a rain garden. Drought-tolerant plants were used in this design as well as reduced turf area.
Landscape architects and designers that utilize these practices will find that their designs are more responsible to the environment and save their customers time and money in the long run. Along with following more accountable design practices, their landscape creations will still be beautiful, functional and enjoyable to the customer.