- Author: Jeannette E. Warnert
- Author: Dohee Kim
Long before European settlers arrived in America, the Los Angeles River was an important source of food and water for native peoples. Europeans settled the Los Angeles area in part because of the river and fertile alluvial soils it provided. The river and its tributaries frequently flooded and changed course, forming wide alluvial floodplains that extended across southern Los Angeles from modern day Santa Monica to Long Beach. When Los Angeles began its transition to teeming metropolis and settled these flat floodplains, the river's natural characteristics led to disastrous flooding.
In the interest of saving lives and property, civil engineers sloped the banks and encased them in more than 30 miles of concrete, a move that completely altered the fishery. In 2010, UC Cooperative Extension completed research that indicated life is still capable of being sustained in the LA River, despite the concrete and influx of pollutants from local storm drains and sewage treatment plants.
Working with Friends of the Los Angeles River, an organization interested in restoring the LA River to a more natural state, UCCE natural resources advisor Sabrina Drill surveyed the fish population in the river's eight-mile Glendale Narrows area, a section that, because of its underlying geology, was left with a natural bottom. The researchers discovered a diverse and bountiful fish population in this stretch of the river.
"To our surprise and delight, toxicity reports show the small number of fish we tested to be free of mercury and have extremely low levels of PCBs," Drill said. "This may not be true for the rest of the river. Glendale Narrows is one of the cleanest sections, probably because the natural river bottom cleans itself and because of the high quality effluent coming out of upstream water reclamation plants."
The survey identified eight species of fishes, none of them native, plus tadpoles and red swamp crayfish in the river. The eight fish species are: fathead minnow, carp, black bullhead, Amazon sailfin catfish, mosquito fish, green sunfish, largemouth bass and tilapia. They hail from Africa, South America, Eastern North America and Asia.
Whether reestablishment of native species to the river is possible remains to be seen, and may not be the most important factor in river restoration.
"Difficult though it may be, you can't make the LA River what it used to be simply by digging up the concrete," Drill said. "Because of all the development, the water we import, and changes in hydrology, temperature, and water quality, it's not the same system it was before people settled here."
According to Drill, large-scale habitat restoration and restoration of some historical floodplains will dramatically enhance the ecological function and natural beauty of the Los Angeles River.
Drill has also served as part of the Technical Advisory Committee for the City of Los Angeles/U.S. Army Corps of Engineers project to restore and revitalize portions of the LA River since 2008. Recently, she began field work to update to the Los Angeles River Fish Study, which she co-authored in 2008.
To view a video about fishing in the LA River, click here. The seven-minute documentary, created by film maker Megan McCarty, includes an interview with Drill.
- Author: Melissa Womack
California has experienced record dry conditions with an explosive wildfire season approaching. The state even declared May 4 to 10, 2014 "Wildfire Awareness Week," urging residents to prepare homes for potential wildfires.
"Creating and maintaining a defensible space is critical for the protection of homes," said Chief Ken Pimlott, director of CAL FIRE. "It has never been more critical to strengthen our fire prevention efforts, in light of the elevated fire conditions we have been experiencing in California. We have increased our inspection staffing and now we need the public to make sure they, too, are prepared for the increased fire risk due to drought."
Homeowners can easily create a defensible space to help protect their homes and improve their chances of surviving a wildfire through easy maintenance practices. A minimum defensible space of 100 feet around your home is required by California law (Public Resources Code 4291). Check with your local fire department for specific defensible space requirements in your area.
Creating a 100-foot space around the home is oftentimes the easiest and most effective first line of defense against wildfires. According to "Landscaping Tips to Help Defence your Home from Wildfire," the goal of the law is to protect the home while providing a safe area for firefighters.
A buffer between structures and trees, grass and shrubs help slow or stop the spread of wildfire. Break your property surrounding the home down into two zones.
-Remove all dead plants, grass and weeds (vegetation).
-Remove dead or dry leaves and pine needles from your yard, roof and rain gutters.
-Trim trees regularly to keep branches a minimum of 10 feet from other trees.
-Remove branches that hang over your roof and keep dead branches 10 feet away from your chimney.
-Relocate wood piles into Zone 2 (see below)
-Remove or prune flammable plants and shrubs near windows.
-Remove vegetation and items that could catch fire from around and under decks.
-Create a separation between trees, shrubs and items that could catch fire, such as patio furniture, wood piles, swing sets, etc.
-Cut or mow annual grass down to a minimum height of 4 inches.
-Create horizontal spacing between shrubs and trees (see diagram).
-Create vertical spacing between grass, shrubs and trees (see diagram).
-Remove fallen leaves, needles, twigs, bark, cones and small branches. However, they may be permitted to a depth of 3 inches.
Again, prepared homeowners are not only protecting their homes, but also providing a safe environment for firefighters responding to the call of duty. Visit The California Garden Web or ReadyforWildfire.org for more information about preparing your home for wildfire season and for information about fire-resistant landscaping. You can also visit UC Cooperative Extension's Fire program.
Photo Credit of Image 2: CAL FIRE, www.fire.ca.gov/span>
- Author: Janet Hartin
- Author: Ben Faber
The use of graywater to irrigate landscape plants is increasing throughout the United States, particularly in California and other arid states. In the United States, "graywater" often refers to wastewater that originates from residential clothes washer, bathtubs, showers and sinks. It excludes wastewater generated from kitchen sinks, dishwashers and toilets (black water).
As of August 2009, a permit is no longer required for the installation of the following single-family or two-family residential graywater irrigation systems, if other conditions are met (California Department of Housing and Community Development): a) a simple clothes washing graywater system as long as it does not require cutting of the existing plumbing piping; and b) a single-fixture system that collects graywater from one plumbing fixture.
All other systems require a construction permit prior to creation, retrofitting, construction and installation as stated in the actual code. The full text of these standards can be viewed at the California Department of Housing and Community Development (HCD) Division of Codes and Standards website. Because these regulations may change at any time, always check with HCD and local enforcement agencies before developing plans for or installing a graywater system. Cities and counties can impose stricter guidelines than the state, so homeowners interested in installing a system should contact their local jurisdiction for specific regulations concerning graywater handling and use.
Laundry-to-landscape graywater systems are relatively simple to install and are inexpensive. The hose exiting the clothes washing machine is attached to a valve that separates graywater from water destined for the sewer. The graywater is diverted through a one-inch main irrigation line with a half-inch tubing outlets that are placed throughout the landscape, terminating in a valve box set called a "mulch basin." The basin surrounds plants being watered.
Benefits and Risks
Using graywater to irrigate landscape plants can conserve water and electricity and reduce water bills by recycling water otherwise destined for a wastewater treatment plant. Since an estimated 30 to 50 percent of home water use produces graywater, significant savings can be realized. A typical household (2.6 people) produces an average of 90 gallons of graywater each day. While most systems will not supply enough water to irrigate an entire traditionally landscaped yard, most can supply 1/2 to 3/4 of the water required by a drip-irrigated, water-efficient landscape with limited or no turf.
The potential risks should be carefully evaluated before deciding to install a graywater recycling system. Graywater varies substantially in quality and potential risks from site to site. Many household cleaning products contain dyes, bleach, chlorine, sodium, boron and phosphate, which can pose significant human and environmental health concerns and injure or kill plants at high dosages over a short period or smaller dosages over a long period.
Impact of Graywater on Human Health
Because of recent changes regarding graywater reuse under California and other state statutes, research pertaining to long-term impacts and risks of graywater reuse on human health, plant health, soil chemistry and ground and surface water quality is very limited.
Research examining the microbial constituency of graywater indicates that direct contact with graywater can pose a health risk to humans. Pathogens can enter graywater through food sources in the kitchen (which is why graywater generated from kitchen sinks and dishwashers is not recommended). Because pathogens can also enter graywater through fecal matter, avoid water contaminated by dirty diapers.
Graywater should not be applied directly to edible plants or root crops. To be safe, it should be applied only to nonedible ornamental plants. Avoid splashing graywater on neighboring edible plants. Also, graywater should not be applied using sprinkler systems, since droplets containing harmful microbes can become suspended in the air and breathed.
Impact of Graywater on Soil Chemistry and Water Quality
Limited research exists that addresses the fate of microorganisms found in graywater and the impacts on indigenous soil microorganisms, soil chemistry and water quality. Soil, rock and other materials that serve as filters can significantly diminish the threat of water pollution from graywater use.
Impact of Graywater on Plant Health
Because graywater is often rich in nutrients required for plant growth, ornamental plants may benefit from its use. However, numerous studies indicate that graywater may contain significant levels of sodium and other salts that are harmful to plants. In general, evergreens are more salt-sensitive than deciduous trees.
For more information on using graywater in urban landscapes, please contact Janet Hartin, environmental horticulture advisor, at firstname.lastname@example.org or (951) 313-2023. For information about UC Cooperative Extension's other programs, click here.
- Author: Dennis Pittenger
Each step can reduce water needs by as much as 10 percent. The impact on the landscape becomes more severe with each step; so stop with the step that results in enough water savings to meet your goal.
Step 1: Fix the hardware. Walk through the landscape while the irrigation system is running. Look for leaks at valves, heads and other parts of the irrigation system. Also, look for heads that apply water on pavement, are blocked by grass or other plant material, have poor spray or stream pattern, and are out of alignment.
Make the necessary adjustments or repairs. Be certain that spray or rotary heads are adjusted and spaced so that they apply water evenly from one head to another. If they do not, heads should be adjusted or added to get uniform water application. Also, be sure your irrigation controller is able to operate at least three separate programs with at least three start times. If it cannot, then replace it with one that has these features.
Step 2: Identify or create groupings of plants with similar water needs. This practice, known as hydrozoning, makes it easier to match irrigation schedules with plant water needs. During much of the year, most landscape plants need water less frequently and in less quantity than lawns. So, be sure each lawn area has its own valve or set of valves. Other areas of the landscape and garden, such as flowerbeds, groundcover areas, or shrub and tree plantings, should be irrigated by separate valves that can be set to water according to the unique needs of the plants.
Step 3: Assess and improve the irrigation schedules for each watering zone (hydrozone). Be sure the schedules for each valve apply the amount of water at the interval that meets the needs of plants without overwatering. Note how often and how long the irrigation system runs in order to keep the lawn and other plants up to standard. Compare these to the following general schedules and adjust yours down, if needed. In most non-desert locations, established lawns during the summer need irrigation no more than three or four days per week, with at least three watering cycles each irrigation day.
To apply enough water and avoid runoff, each cycle needs to run about 5 to 25 minutes, depending on the heads being use (rotary or fixed spray) and the amount of slope in the planting. Observe how many minutes it takes for runoff or puddling to begin. Then, take one minute off. This should be the maximum time at which you set one cycle. Cycles should be timed so that there is a break of several minutes to an hour between starts for each valve.
Established trees, shrubs and groundcovers usually need less water. Their irrigation should be less frequent (usually no more often than every 4 to 10 days in the summer). But enough water needs to be applied on a watering day to wet the soil about a foot deep. Again, schedule multiple cycles or use drip irrigation to do this without runoff.
Step 4: Reduce the amount of water applied to less than optimum. This practice is sometimes called deficit irrigating. With lawns and other frequently watered plants, reduce the runtime minutes by about 10 percent. For trees, shrubs and groundcovers, it is best to keep the runtime minutes the same and slightly extend the days between irrigation.
Lawns may develop some brown spots, and other plants may develop signs of drought stress.
Step 5: As a last resort, reduce the planted area being irrigated. First, consider reducing turfgrass areas or discontinue irrigating turf areas, as these are replanted more easily than groundcovers, shrubs or trees.
This step is the most dramatic and can yield some substantial water savings if large areas are stripped of plants or go unirrigated. Taking this action can also have significant negative side effects, such as increased heat load and dust in the area because the plants are no longer there to supply evaporative cooling, humidification and wind modification.
- Author: Keith Nathaniel
- Author: Dohee Kim
Last summer, I was reminded of why I get so much personal and professional satisfaction from being part of UC Cooperative Extension.
I was having a discussion with a group of 4-H youth, preparing them for summer camp as staff members. I was talking about their important role to serve as mentors and provide a memorable camp experience to more than 100 youth. It was at that moment when I realized that our program must have been important and meaningful to them because they have volunteered for a week to give that same experience to a new group of kids. For them, 4-H meant something, and they wanted to share it with others. That was a powerful realization.
Like the volunteers, I wanted to share what I experienced as a youth growing up in local youth programs in Compton. Nearly every day after school, I was fortunate to play, learn and grow in an after-school environment that nurtured my interests and skills in a safe place. The program staff were committed to providing this experience to all their youth participants. Field trips and overnight camping trips to Catalina Island as well as year-round sports activities helped to keep me safe and away from unhealthy, risky activities.
I also realized how important non-parental adults can be to young people. They help broaden the context of life and guide youth through experiences and opportunities that lead to a thriving adulthood.
So, I understand why these 4-H youth gave up part of their summer to be volunteer mentors. I, too, felt that need to share my positive youth experience with others. It is a wonderful thing to want to share.