OPINION: Enjoying The Results Of Rainfall

We hope readers had an opportunity to check out the time-lapse video on our website of Cachuma Lake responding to recent heavy rains, and slowly filling up. It is breathtaking to watch. Although heavy winter rains can be a major pain, we also must acknowledge their overall benefit of bringing something we desperately need — water. It’s easy to overlook the recent years of severe drought conditions when it’s pouring outside, but drought is one of the facts of life in California, and will likely continue to be in all of our lifetimes.

Using devices like this rain chain can help you slow and store rainfall for later use. Photo: Contraption/Flickr-Creative Commons License

Catch the Rain By Slowing and Storing It

If rain gutters are installed on your house, water will be directed into downspouts, where it can move with great force and speed. This is especially true in a large storm. Instead of allowing downspouts to discharge directly on hard surfaces like a driveway, path, or patio, think about ways to redirect downspout water into vegetated landscape areas. 

One option is to replace downspouts with rainchains to slow down the water so it can be more easily absorbed when it reaches your landscape areas. Add a rain barrel or cistern at the bottom of downspouts or rainchains and let it overflow into the garden. 

If rain gutters are not installed, water shears off roof surfaces and can cause erosion damage. Areas under the eaves may be covered in permeable groundcovers such as pea gravel, mulch, or rocks to reduce the compacting force of water falling on bare soil. Spreading fresh leaf and wood chip mulch throughout the garden will slow down water. Healthy soil can withstand even the strongest rain.   

Ways of storing rainfall  

Rainwater can also be harvested and stored. Storage vessels include rain barrels and cisterns directly connected to downspouts  

Stored water can be released gradually into the landscaping between winter rainstorms, building up the soil sponge and ensuring that native plants get adequate water during the winter months when they need it most. If you need water in the summer and capture enough of it during the winter, you may be able to use your cistern water for irrigation  

Both rain barrels and aboveground cisterns can be relatively inexpensive to purchase and easy to install. Mosquitos are kept out using screens. With minimum maintenance and common sense, the water can be kept safe. If you plan to store rainwater, make sure the “first flush” is diverted directly into the landscaping before capturing the rainfall that follows.  

Properly placed trees also are excellent landscaping features to help capture rainfall, allowing it to be released slowly over time into the soil.  


This article was inspired by the 71-page Sustainable Landscapes Program guidebook available at The Water Authority and its partners also offer other great resources for landscaping upgrades, including free WaterSmart classes at 




Historic Rainfall Wipes Out Drought For Most Of California

The latest report on California’s water conditions has been released and the drought monitor shows some encouraging news about our drought levels. Experts say it has very little impact on our local supply. KUSI’s Ginger Jeffries explains.

Valley Water Agencies Say They’re Prepared To Handle This Year’s High Rainfall

Our above-average rainfall is a concern for several water agencies in the Central Valley. While the high rainfall totals are a good thing, there is the task of how to manage and store all that water. The California Water Institute at Fresno State does just that. They say a valuable lesson was learned during the wet year of 2017. “A lot more of the agricultural entities in particular and even some cities are using a lot of their facilities for recharge this year to get much of that water into the ground,” said Sarge Green, Water Management Specialist.

Santa Barbara County, Water Agencies Clash On Ending Drought Emergency Proclamation

Local water agencies say both of these things are true: The drought is over for most of California, and southern Santa Barbara County has water shortages. Office of Emergency Management Director Robert Lewin recommended that the county Board of Supervisors terminate its proclamation of a local emergency due to drought conditions, which has been renewed every 60 days since January 2014. The drought emergency relates to climate conditions, and public peril and safety, and this winter’s rainfall amounts and snowpack indicate that the drought is over, he said at Tuesday’s supervisors meeting.

The first rain after a dry period is called the "first flush." It can wash pollutants off hard surfaces. A better alternative is to filter the first flush through your landscaping. Photo: Skyloader.Creative Commons

Capturing the First Flush of Rainwater

The most important water to capture in your landscape is the first inch of rainfall after a dry spell. This is called the “first flush.”  

Rainfall in dry climates like the San Diego region is often a “first flush” repeatedly due to long stretches between rainy periods. 

The first rainfall washes away pollutants that have gathered on hard surfaces since the last rain. It needs to be filtered as much as possible by landscaping before it goes anywhere else, especially into storm drains that empty into the oceans. 

How much water comes off your roof? 

The shape of your roof doesn’t make any difference. The same amount of water falls on the roof whether sloped or flat. Measure a sloped roof either using an aerial view or from the ground without worrying about the slope itself. Just measure the outside edges the same way you would if it was flat, and calculate the square footage. 

Flat roofs covering a building in one contiguous shape are easier to measure. Some roofs are more complicated. Divide this type of roof into individual squares or triangles. Measure each one at a time, then add the figures together for your total roof area.  

Calculate your potential water capture  

Once you know the total roof area, you can determine the amount of rainfall it generates in gallons, then use the following formula to convert square feet to gallons.  

Formula: Rainfall in Inches x Total Square Feet x 0.62 = Gallons of Rainwater From the Roof 

Example using a 1,000 square foot roof: 1 inch of rain x 1000 x 0.62 = 620 gallons. 

San Diego’s rainfall total for “water year” 2018 was about 3.3 inches. Imagine this amount falling on a 1,000 square-foot roof. The total amount of water runoff during this water year would be 3.3 X 1000 X 0.62 = 2,046 gallons.  

Even in our dry climate, this rainfall adds up to a lot of water runoff. It’s easy to see how important it is to save as much of this water as possible in a landscape designed to be a sponge instead of a brick.  


This article was inspired by the 71-page Sustainable Landscapes Program guidebook available at The Water Authority and its partners also offer other great resources for landscaping upgrades, including free WaterSmart classes at 




An Atmospheric River Could Bring Torrential Rainfall To California Over Several Days This Week

California has all the elements in place for nasty flooding because of an “atmospheric river” event: Waterlogged soil from an already-wet winter? Check. Many square miles of land scorched by fire? Check. A thick snowpack on the mountaintops? Check. And wouldn’t you know it, the hours are ticking away before another atmospheric river makes landfall somewhere in the Golden State. Welcome to West Coast winter 2018-2019, responsible for a snowbound Seattle (the most snow in February since the Truman administration), a soaked Los Angeles (its wet season rainfall exceeding 13 inches, more than 50 percent above average) and totally stoked skiers in between.

The California Department of Water Resources conducted the second snow survey of the 2019 season at Phillips Station in the Sierra Nevada Mountains. The survey site is approximately 90 miles east of Sacramento in El Dorado County. Photo: Florence Low / California Department of Water Resources.

Mid-Winter Storms Drench California, Boost Sierra Snowpack

A remarkable series of winter storms in January and early February has doubled the Sierra Nevada snowpack and recharged reservoirs across the state of California. With more rain and snow in the forecast, California’s water supply picture is far better than it was a year ago, when San Diego received the second-lowest amount of rainfall on record since 1850.

In San Diego County, Lindbergh Field has recorded more than nine inches of rain since October 1, which is nearly the average annual rainfall of 10.33 inches, according to the National Weather Service. More storms are on the way: NWS has forecast more showers in the next few weeks.

Some of the wettest local spots include Mt. Woodson, which received 4.34 inches of rain in the past five days, Lower Oat Flats with 4.08 inches, Rainbow Camp with 3.6 inches, and Fallbrook and Bonsall each with 3.41 inches.

Local rainfall is important, because it allows residents and farmers to reduce or eliminate irrigation for weeks or months at time while Mother Nature does the work. In addition, local surface water meets about 10 percent of San Diego’s annual water needs. From a supply perspective, it is much more important snowpacks continue to grow in the Rocky Mountains and the Sierra Nevada.

Water conditions far better than 2018

Surveyors with the California Department of Water Resources recorded 50 inches of snow and a “snow water equivalent” of 18 inches on January 31 at Phillips Station, where DWR has conducted manual snow surveys for decades.

This was the second of five snow surveys planned for this winter. More than 50 agencies at the local, state and federal levels collaborate on the Cooperative Snow Surveys Program to collect snow data from more than 300 locations statewide each year. Results from these surveys are crucial to water management in California.

The most recent survey at Phillips Station showed the snowpack as 98 percent of average to date – just shy of the statewide average. By comparison, on February 1, 2018, measurements at Phillips Station showed a snow water equivalent of 2.6 inches – just 14 percent of the early-February average. Snow water equivalent is a standard metric of how much water is held in snow.

In the Upper Colorado River Basin, conditions are slightly better than they are in California – a good sign for a region that has suffered nearly two decades of drought. Precipitation and snow water equivalent were both at 105 percent of average at the end of January.

No shortages are expected on the Colorado River system in 2019, though long-term drought conditions continue to be a concern across the Southwest.

San Diego well-positioned to meet regional water demands

The National Weather Service reports that between Oct. 1, 2018, and Feb. 6, 2019, San Diego County received more than nine inches of rain at Lindbergh Field, which was 165 percent of normal, and more than 11 inches of rain at Ramona Airport, which was 142 percent of normal.

“This winter is shaping up nicely,” said Jeff Stephenson, a principal water resources specialist at the San Diego County Water Authority. “A well-timed string of storms and cooler temperatures is allowing us to leave water in storage for use during the dry summer months – and it’s important that everyone continue to leave off their irrigation systems while there’s plenty of water in the soil.”

No matter how the winter plays out, the Water Authority and its 24 member agencies have enough water to meet regional water demands for the foreseeable future. This is made possible by a combination of investments in drought-resilient resources, including the Claude “Bud” Lewis Carlsbad Desalination Plant, conserved agricultural water transfers and continued water-use efficiency measures.

Rain Harvesters Pocket Funds From City Rebate Program

Recent rainfall is filling the pockets of some San Diego residents who partake in rebate programs for harvesting rainwater. The area is seeing an increase in rainfall this rainy season and many residents are thinking smart. Rainfall totals are up by 2.67 inches since the start of the rainy season in October, according to the NBC 7 First Alert weather team. San Diego International Airport’s rain tracker has seen 3.5 inches of rain since the start of this year alone.

First Of Two Storms Could Drop 0.50 Inches Of Rain On San Diego On Thursday

The first of two Pacific storms will make shore late Wednesday night and drop between 0.25 inches and 0.50 inches of rain in greater San Diego during the day and evening, according to the National Weather Service. Daytime high temperatures will low be in the 60s at and near the coast, and the 50s and 40s inland. The second system is larger and colder. Forecasters say that storm will move into the region on Friday night and drop moderate to heavy rain on Saturday, and lighter, more sporadic precipitation on Sunday and possibly Monday.