Rain: friend and foe?

Fallbrook’s recent deluge of rainfall is fraught with good and bad scenarios. Rainfall has an impact on three major areas in Fallbrook: water we use in our homes and for agricultural irrigation, water that reduces fire danger and water that nurtures our natural plant life.

Rainfall to offset water purchases

Joe Jackson, Fallbrook Public Utility District civil engineer and 20-year veteran of water wars, is frustrated. Ten years ago he spearheaded an effort to transfer one of FPUD’s three water permits to divert water at Sandia Creek to capture water at Lake Skinner. During the 1993 storm season, Jackson says, Lake Skinner captured 12,000 acre feet of water. If Fallbrook’s water permit was in place in 1993, it could have used 1,000 acre feet of that water, a value of $500,000. Although everything is in place to use the permit now, a judge imposed yet another public hearing before the Federal watermaster steering committee. It won’t take place until January 18. “And now, guess what? For the first time in ten years, it’s raining,” Jackson says. “We’re not going to be able to catch that water and I’ll be dead by the next time we get another chance!” Jackson faults bureaucratic red tape for the delays. During the summer months, it seems like the approval times are reasonable, hence Jackson’s frustration at yet another delay. Asked why he thought the delays occurred, he responded, “There are people more interested in process than results.” To put this in perspective, from June 20, 2004, to January 7, 2005, Fallbrook received 16.68 inches of rainfall and the only capture tank now is on Red Mountain — minuscule capacity compared to the need.

Green now, but fire fuel in October

Chief Bill Metcalf, North County Fire Protection District, has other concerns. While he isn’t a climatologist, he believes it will take years to end the drought. A look at the reservoirs indicates they’re still down, but as far as the impact on fire danger there’s good news and bad news. In the short term Metcalf says everything is green. But the only plants that have turned green are those alive, whereas the dead and dry brush and trees which fuel fires are still there. Once they’ve dried out, the danger returns. In the canyons there is a tremendous amount of brush. The riverbeds and canyons are problems, but “the ones we tend to think of most dramatically are DeLuz canyon and the area along I-15.” Metcalf’s optimistic for a while. “The fire danger has significantly lessened,” he says. Although a flush of green after a rain would appear to lessen fire danger, Metcalf explained the method they use to determine fuel moisture is more scientific. First, a piece of wood cut from live vegetation is weighed, then baked to remove all moisture, then weighed again. The percentage of moisture loss is expressed as fuel moisture. This process is repeated regularly. For live fuels or growing plants can have up to 300 percent of their weight in moisture regardless of its variety, Metcalf says. Dead fuel moisture is influenced by how much its exterior absorbs water, which can change on a minute-to minute-basis. “Moisture in dry fuel can drop into the single digits and go up like a candle,” Metcalf says. “All it will take is a few days of sunshine and a Santa Ana wind blowing, and we’ve got a problem,” Metcalf says. The irony of this wet weather is although it produces lush plant growth, next September or October when it’s brown, it’s a hazard. “In wet years we grow fire fuel, but later on we pay a price,” Metcalf warns.

Nature welcomes the rain, but does agriculture?

Fallbrook’s resident tree expert, Roger Boddaert, believes the rain will enable the region to start to come out of its seven-year drought. Because of the drought, Boddaert says, the native trees, particularly pines and oaks, were going into water stress. When they don’t have proper moisture they start to shut down, leaving them vulnerable to insects and pathogens. Two current concerns are the beetle and borer infestation of pines and oak root rot. Most of the pines in Fallbrook are not native; thus, they live in some degree of constant stress. Drought makes them even more susceptible to insects or disease. Even though oaks may not appear to be thirsty, they grow naturally alongside rivers and creeks, sending their roots deep into aquifers. They also process moisture through their leaves, so when rains of this consequence occur they become laden with water and heavy. Some Fallbrook oaks infected with root rot and other types of pathogens are falling victim to water saturation and losing limbs or toppling over. “I’m getting many calls from people asking for help. What can we do? Can we brace the tree?” Boddaert says. Tree weight is significant and can determine whether the tree can be saved. “We’re talking about boughs and branches that weigh tons, not pounds. When the root system has also been affected by root rot, there is more danger of the tree falling.”

As far as agriculture goes, Boddaert says, “This rain is a good douche for avocados; it’s fabulous for cleaning the leaves.” The rain rids avocados and citrus of red spiders and mites. “Avocados are real drunkards, too,” he quips. “Although avocados have enormous canopies and weight, they do not seem to be as breakable as oaks,” Boddaert says. Rain of this duration also flushes salt and chemical residue left in the soil from irrigation water. Boddaert cautions that although on the plus side the rain will help build the water table, soil and water pathogens will flourish — a dilemma facing flower growers. Proteas, for example, hold water in the cups of their flowers. They have to be cleansed of water before they are packed and shipped to avoid rotting en route.