Going Underground in the Salt Creek Watershed

"Curvature Drain"

Orange County is built on arid land, a coastal desert. In the San Joaquin Hills, South Orange County, houses are built on hilltops and roads are built in canyon bottoms. In this land dominated by fog and sun, rain is a rare treat. The mud that makes these hills is oceanic sediment, deposited over ten million years ago when the sea level was much higher. This mud is largely clay, and is filled with sandstone outcrops and rocks. Water does not sink into this mud very well, and when it does, the land slides. Water usually runs off the hills in sheets in heavy rain, and floods the streets and impermeable clay. Because of this, a massive network of storm drains runs under the area, all emptying into the local ditch–er, creek. The drains mentioned here all drain the Salt Creek Basin, which are the most easily accessible of the large drains. I won't disclose entrances because Its fun to find them or search for them. In the following post, three of the largest tunnels are lectured on which I have given names to make them more interesting.

"Curvature Drain"

Looking in the entrance. Notice the difference in graffiti
to the top image.

This first one I will share is the first one I truly explored, I knew of several others but never checked them out until this time when I went with a friend. It carries Salt Creek a quarter mile under a main street. The first half is the part I've explored; a seven-foot diameter reinforced concrete tube under road fill. It does not have many interesting features but is fun because of the low water flow and easy access. The second half is older, and much more slippery. I haven't explored it yet because of the extra effort needed to do so. It is a corrugated metal pipe seventeen feet in diameter.

Looking out from inside.

Into the depths

One of my all-time favorite pictures. One second exposure.

Same properties as above photo, just out of focus.

At this point, the water falls several feet down steps into the bottom of the corrugated metal tunnel.

The insides of these tunnels is very humid, thus the light creates a beam.

Looking toward the entrance. 

Same as above, with flash. That's an eighteen-inch pipe coming in on the left

Gross inflow.

The icky inflow into this drain.

"Baking Soda Drain"

The foreboding entrance

This next drain labyrinths underneath a large network of streets and runs comfortably for over 1.25 miles until becoming too small. This is one of the largest drains to flow into Salt Creek, as it is a tributary. It starts as a ten foot concrete tube at its outflow into Salt Creek, and at the point I turned around it was still at eight feet, after about three-quarters of a mile underground. The lower part is full of graffiti, as is expected, and it has many interesting mineral deposits within. I will return one day with a better camera.

This drain is about ten years older than the previous one, so it shows more signs of wear than the former.

Looking out

Deep within. There were frequent water seeps
and mineral deposits on the walls.

Looking up a wet manhole near where we
stopped.

Daylight at last, only one half of this drain
has been explored by me.

Interesting thing about this drain is that if one sings or hums a tone, the resonant frequency to the entire tunnel can be reached. I found the resonant tone to be a low D. The reverberation of this tone lasted for probably thirty seconds.

"Gothic Channel"

The final drain in this post is the last channel before Salt Creek enters the sea at the beach. The seaside entrance has been gated closed to prevent debris from washing into the ocean, so access must be made another way. 

Anyway, this drain is unique because it has three different phases, each built at a different time. The most upstream is two boxes, each ten feet in diameter by thirteen feet high. Two main drains empty into this one: the eight-foot drain from Dana Point (to be explored), and a three-foot drain from a nearby housing development. This channel was built in the early 90s, when the St. Regis and neighboring golf course were built and serves (it appears) to transfer the flow from its new, elevated course after the golf course was built course to the original level it flowed at. This channel is scary to enter if it is too wet, as the entrance becomes very very slippery. This upper part has some... interesting graffiti that I didn't bother taking pictures of.

Down the left channel, the eight-foot pipe coming in
on the left.

Looking out the top and the slippery slope of doom.

The second phase, the middle and oldest one, is a large arch twelve by thirteen feet tall. It is the shortest segment, and this I believe is because it was built along with this southern part of the Pacific Coast Highway. If this is true that would date it around 1926. I haven't examined it for signs of such construction, but I shall in the future. This section is plagued by the infamous "Orange Sludge," a bacteria or algae goo that accumulates in deep and slippery mats in some of the drains. I have discovered one patch in Baking Soda Drain, but other than that not outside of this part of the channel. 

Orange Goo of Doom. The goo is slippery,
deep, and sticks to your shoes, Fortunately
there is ample water to wash in, just don't
put it on your face.

Terrible picture showing the box from
the arch segment.

The third phase of Gothic Channel is the modern box twelve by fourteen feet that was built at the same time as the upper portion and flows under everyone's favorite golf course. It't a very bland structure, but as the high water marks show, crucial to the non-flooding way of life. Interestingly, these lower two sections of this channel are one of the only places where the drain follows the undisturbed creek bed of Salt Creek. Also, these tunnels were built using plywood forms. The arch has wood grain imprints on its ceiling where the arch was formed, and pristine plywood grains are found in the lower and upper channels. At the terminus of this channel, an ozonation port was built to disinfect the water before discharging into the ocean. It is rather pathetic and treats probably 30% of the actual water that flows over, not through, the apparatus. 

From the Seaside entrance. This portion now
has a foot of standing water in it thanks
to the grate.

Overall, the Orange County Labyrinth extends for untold miles under the cities of this area, and provides endless hours of exploring fun for those willing to get a little wet.