Friday, April 12, 2013 at 12:51PM
By Jessica Romer, Community Initiatives Coordinator
Each summer, as we see green lawns, abundant flowers and trees all around us, it is easy to forget that we live in a semi-arid climate. Though the Rocky Mountains in Colorado create the headwaters for four major watersheds, not all of this water belongs to Colorado residents. Colorado headwaters supply water to nineteen other states and Mexico. Thus, drought in Colorado is not just a local issue – it is of international concern. Drought is not uncommon in Colorado; in fact it rears its head somewhere in the state almost every year, resulting in forest fires, crop failure and consumption of water reserves. However, severe drought only pays a visit every decade or so. Our most recent drought in 2002 was more severe than in decades past, but relatively short-lived.
As of April 8th, Denver Water’s reservoir supply is well below that of 2002. From Denver Water: “The Denver area is in the second year of a serious drought that’s not getting better. Denver Water’s reservoirs didn’t fill last year, and the mountain stream flows that feed our reservoirs are expected to be well below normal. Based on the conditions we are seeing today, this may shape up to be Denver’s worst drought on record.” Statewide, snowpack is at 69% of normal. Despite our recent precipitation and lower than average temperatures, a March update from the CO Water Conservation Board and CO Division of Water Resources states that “275% of normal precipitation would be needed to reach average peak snowpack statewide, which typically occurs on April 8th.” It is very unlikely at this point that we will catch up.
Drought is particularly concerning because its length is unpredictable. Thanks to the planning efforts of water utilities, we typically have enough water to withstand a one to two year drought. Though droughts that last longer than two years are rare, we must think longterm. It can take years to replenish reservoirs, so there are no quick fixes to drought. Water utilities are genuinely concerned about being able to conserve the water supply after this year, so we must plan and act with the assumption that the drought will continue.
Denver Water has changed their slogan from the familiar Use Only What You Need to Use Even Less. As citizens, mandatory water restrictions challenge us to consider what we really need versus what is habitual and comfortable. When water is as easily accessible as turning on a faucet or spigot, we take for granted the readily available water. For example, Denver Water tells us that three to seven gallons of water run out of a hose every minute that it is on, depending on the pressure. If we water our garden for twenty minutes, the simple math tells us that we just used 60-140 gallons of water. That doesn’t seem like much when you consider that in 2012 some customers paid just $4.81 per 1,000 gallons of water. But we must broaden our perspective and see ourselves as individuals within a community of water users. Denver Water has stated the need to save 16 billion gallons of water this year. We cannot do this alone.
On April 1st, Denver Water declared a Stage 2 drought with mandatory restrictions. Vegetable and annual gardens in Denver Water’s service area may be watered any day of the week with a handheld device or drip irrigation. Denver Urban Gardens is taking one step further to require watering before 10:00am or after 6:00pm in DUG community gardens. You can view a full list of Denver Water’s restrictions here.
Outdoor water use accounts for 55% of residential customers total water use in Denver; the other 45% of water is used indoors. Toilets use 11%, clothes washers use 9%, showers use 8%, leaks use 7%, faucets use 6% and so on. The EPA estimates that more than 50% of water used in outdoor landscapes is wasted due to poor irrigation practices.Because of the enormous potential for improvement, water conservation programs often target outdoor water use.
Overall, Denver Water is asking for a 20% reduction in outdoor water use. Given that water use overall has decreased since 2002, this year’s reduction will be harder to meet than in the last major drought. Rates are also increasing by up to 20% this year. However, if we are able to meet the 20% reduction, the 20% rate increase will be irrelevant.
As community gardeners, we are presented with both an opportunity and a responsibility to model efficient water use and to educate our neighbors regarding water conservation. As DUG community gardens are very visible in the community, it is imperative that community gardeners model resourceful and efficient watering practices. We want to be exemplary stewards of our community watershed.
Community vegetable gardens actually use about half the amount of water as an equal size area of turf, and are relatively water efficient due to hand watering practices, not to mention gardens produce a valuable product in the vegetables grown. These reasons contribute to Denver Water’s decision to support vegetable gardens, so long as they continue to enact wise water practices.
The first step in practicing smart water use is becoming aware of how we use water and how the soil and plants use water. In the vegetable garden, we can follow a few simple guidelines and become experts at reading our plants and environmental indicators so that we use just the right amount of water, no more and no less.
- Water when the plants and soil need it, not out of habit. With the exception of the beginning of the season when young plants and seeds are establishing themselves, vegetable gardens should only need to be watered two-three times per week. Even in the heat of summer, gardens do not need to be watered daily. Though it may not be intuitive, we are actually watering the soil, not our plants. Plants absorb water through their roots in the soil, and plant roots grow towards water in the soil. When a gardener provides smaller amounts of water on a frequent basis, the roots have no reason to expand into a strong, expansive system. This practice can be very detrimental to plant growth and is an ineffective use of water. The smarter technique is to water less frequently, but deeper. This practice, especially employed early in the growing season, encourages plants to grow deeper roots that will help them to maintain strength during the hotter, drier periods later in the growing season.
In the heat of the day, plants may look droopy, and soil often looks dry from the surface. Before going straight to the hose, take a moment to dig into the soil to determine if the buried soil is as dry as the surface. If so, it’s time to water. Before doing so, use a hand tool to lightly break up the crusty surface of the soil between plants so that water can easily penetrate. This can be done on a weekly basis to encourage soil health throughout the season.
- Get to know your soil. Water must first be able to enter the given soil, and then the soil must have the capacity to hold the water so that it is available for the plants. Clay soils are dense which makes it difficult for water to enter the soil. Once water does percolate into the soil, clay soils will hold water much better than sandy soils. Water percolates through sandy soil very quickly, but also dries out faster, so plants will require more frequent watering. You can easily determine what soil texture your garden has by doing a simple ribbon test. Whether you have clay or sandy soil, adding compost breaks up dense clay soils making it easier for water to penetrate and improves the water holding capacity of sandy soils. Soil enriched with compost can result in a 20% decrease in water usage. Add one to two inches of compost to the garden in the springtime.
- Water by hand. The EPA estimates that gardeners who water by hand use 33% less water than those who use automated irrigation systems. Hand watering allows gardeners to respond to changing soil moisture conditions as watering occurs. For instance, when water begins to pool on the surface, stop watering. Wait for the pool to disappear and then try watering again. If the soil accepts the water, then continue watering until water has penetrated just beyond the root level. You may need to dig around with your hands initially to get a sense of how much water is needed for your soil. This practice uses water more efficiently by getting water into the target area, which reduces fugitive water and is more beneficial to plant health. Be sure to target water towards the soil at the base of the plants, being careful not to water the plant’s foliage.
- Reduce water loss. Evaporation is water loss from the soil surface and transpiration is water loss from the plants’ foliage. To limit evapotranspiration (ET), plan your garden so that the leaves of mature plants are just barely touching. This limits the amount of exposed soil that is susceptible to evaporation. Mulch so that you have little to no soil exposed on the surface. Mulch reduces the amount of soil exposed and in turn reduces the amount of water needed, particularly in sandy soils. Newspapers, straw (my personal favorite), dry grass clippings that have not been treated with chemicals are all relatively inexpensive and free mulch options. As mulch decomposes, it increases the organic content of the soil, which provides a consistent source of nutrients throughout the season. ET is highest during the heat of the day. Watering before 10:00am or after 6:00pm allows plants to better access the water provided to them, as opposed to the water evaporating before it gets down into the plants’ root zones. Water loss can also occur from loose hose connections. Always use a nozzle on the hose for quick shut off. Make sure to tighten your hoses and use o-rings in the base of the hose so that water doesn’t drip unnecessarily. O-rings can fall out of hoses or dry up in our climate, but replacements can be purchased at any hardware store.
So this summer, push your plants to their limits. It will make them stronger in the long run. Water deeply, only two-three times each week. Challenge your fellow gardeners to model responsible gardening practices by collectively using as little water as possible. For example, set up a watering schedule for common areas in your community garden to prevent overwatering. Water conservation will help your garden have less weeds, lower water bills, and help to maintain a positive image of community gardens across the city. Unless citizens take action now to conserve water and reduce consumption, this drought could become a Stage 3 drought, which mandates no outdoor watering (with the exception of some trees). This would be damaging to landscapes and the economy throughout the Metro area. Let’s look at our water use, in our gardens, homes, and workplaces and see just how little water we can use while still meeting our basic needs. Every drop saved is one more drop available for a time when we may need it even more than now.
Each water utility has different reservoirs, supply areas and water systems, and thus each will be unique in their drought declarations this year. Not sure who your water provider is? Check out this website to find out.
tagged Spring 2013, T
