Soaked With Record Rainfall

Posted by on Oct 15, 2009 in Farm Blog | Comments Off on Soaked With Record Rainfall

Earlier this week we endured the worst single October storm to hit this region since the Columbus Day Storm of 1962.  On October 8th, a Super Typhoon named Melor, with 125 mph winds, slammed into Japan, killing at least four, and leaving more than 100 people injured.

NASA Satellite Image of Super Typhoon Melor on October 5, 2009

The remnants of that typhoon then merged with another low pressure system in the Pacific Ocean en route to the coast of California, prompting the National Weather Service to issue this advisory last Thursday night, with an estimate for the storm’s arrival here the morning of October 13th:

“RAINFALL AMOUNTS WILL RANGE FROM 3 TO 6 INCHES…WITH LOCAL AMOUNTS UP TO 8 INCHES. AS OF NOW…THE HEAVIEST RAIN LOOKS TO BE IN THE SANTA CRUZ MOUNTAINS. WINDS TUESDAY AND TUESDAY NIGHT WILL INCREASE TO 20 TO 40 MPH ALONG THE COAST AND IN THE HILLS. GUSTS TO 60 MPH ARE POSSIBLE IN THOSE AREAS.”

The advisory told us the storm would be big, we just didn’t know quite what to expect if the storm really managed to dump up to 8 inches of rain at once.  With five days warning that the storm was heading straight for us, we spent all of last weekend getting prepared.  We’ve been through many big storms in the Santa Cruz Mountains over the years, but 8 inches of rain from one storm seemed absolutely daunting.  By Sunday night we felt we were as prepared as we could be.  The roof tops and gutters were clean, the drains were cleared of brush and debris, we’d stacked some firewood, stocked up on candles, and we fueled up and tested the generator.  The rest was up to nature.

The first of the rains showed up here by about 4AM PDT on Tuesday, October 13th, exactly as predicted.  Winds were gusting so hard that morning that some of our younger bay trees were bending almost at right angles on the hillside, and between 8:00-9:00AM the rainfall amounts here reached a whopping 1.25 inches per hour!  Thankfully the rainfall rate didn’t stay that high, but the rain was heavy, and the winds quite fierce, for the remainder of the day.

Map showing projected precipitation amounts from Tuesday’s storm

I spent most of the daylight hours on Tuesday during the storm completely soaked through to my skin.  When I wasn’t clearing drains, I seemed to be constantly changing out of wet clothes between torrential downpours.  My previously reliable rain jacket was soaked far beyond its capacity to repel any more water, and so much rain had run down into my rubber boots by early-afternoon, that my toes were pruned.

Early in the morning sounds of snapping branches, and cracking tree trunks, filled the canyon behind the house.  The first tree we saw fall during the storm was a rather sickly bay laurel on the hill behind the the chicken coop, and it was snapped almost completely in half during a brief, but severe, wind gust.

Strong Winds Snap a California Bay Laurel in Half

The wind throughout this storm was phenomenal, often seeming to blow straight down, bending tree branches flat down against their trunks.  Then just after 11:30AM, we hear a loud boom from a falling tree, and we lost electricity service to the property.  By Noon another tree fell across our lower parking spot, where less than 24 hours prior we’d had two vehicles parked.

A Sick Tan Oak Tree Decapitated by Tuesday’s Storm

The cars fortunately were unscathed.  However, the winds were only part of the problem…there was also the rain.

Although the drains had been cleared, so many leaves, and so much redwood debris was knocked out of the trees that the drainage ditches quickly filled up, and torrents of water came gushing down the mountain.  Our main drainage alongside the house has a large diameter drain pipe that runs underground, but also has an overflow chase at surface level in case the pipe gets clogged.  By 2PM I was running up and down the hill with a shovel and post-hole digger, clearing out numerous rocks, clumps of mud, and small dams of branches and leaves, trying to keep the water flowing in the direction of the creek.

Dam It!  Numerous Dams of Branches and Leaves Formed Throughout The Drainage Channels

A Dam of Branches and Leaves Blocks The Overflow Channel (left); Blockage Cleared, Restoring Water Flow (Right), but the Underground Drain is Still Clogged

I managed to get all the lower drains cleared at one point, and went to clean out the drain toward the top of the slope behind the house, when another tree came crashing down the hill due to the strong gusty winds…causing me to drop my shovel and run for cover.  The entire afternoon was spent patrolling and cleaning drains, changing soaked clothes, patrolling and cleaning drains, changing soaked clothes…you get the idea.

Thankfully, by nightfall, the storm began to calm down, and by 9PM 8.27 inches of rain had already fallen, in just 17 hours!  That’s an average of almost half an inch per hour.  I can’t complain we really needed the rain…though maybe not all at once would have been preferable.  Although the ground was bone dry prior to the storm, because so much rain fell so fast, most of it seemed to run down the hills, into the creeks, and out into the ocean, rather than soaking in.

With Little Chance to Soak In, the Water Fills the Drainage, and Rushes Toward the Creek

By Wednesday morning the majority of the rain had passed.  Overall we were relatively unscathed, and the total damage here was actually less than we expected for the magnitude of this storm. We did have a number of downed trees around the property, one of which fell across our roadway.  Part of our orchard slope, where we need a retaining wall, did start to slip, but in an area where it has clearly slipped before.

The Toe of the Orchard Slope Collapses

The Toe of the Orchard Slope Collapses

The ground itself didn’t seem completely saturated, but a small underground spring sprung up during the storm, and eroded away some of the soil at the toe of the slope.  Now the storm has passed, the soil seems stable, but we will need to keep an eye on it for the remainder of the season.  Other than that, we did spend a total of 45 hours without electricity, which finally was restored this morning.  Our utility company did advise us to prepare for an extended outage period after the storm caused 209 outages, affecting more than 5,000 customers, in Santa Cruz County alone.  That’s where the candles and our trusty generator both came in very handy!

By yesterday morning the bulk of the storm had passed through, though the skies remained cloudy, with intermittent rainfall, but this morning the sun finally managed to break through, and the ground is now starting to dry out.  All in all this storm, after dumping a total of 8.75 inches here, could have been much worse, and if we had to endure a storm of this magnitude, we’re grateful that it hit early in the season, before the ground was saturated from winter rains.  As much as we need the rain to help put an end to fire season, and an end to our ongoing drought, we’re hoping the remainder of our rainy season will be less…how should I put it? Exciting?!