Wow!

The contractor has started removing vegetation from the sides of the stream and the effect is stunning. Removing a patch of overgrown shrubs opens up a whole area to sunlight and opens vistas that no one has seen in years (maybe decades). In consultation with City staff and the project landscape architect, non-native and selected native vegetation is being removed. As you can see in the photo, natives to be preserved in the midst of exotics to be removed are tagged so the heavy equipment operators can easily see what is what. Some natives have to be removed due to their condition or location, but the vast majority of removals are exotic invasives (privet and pepper). We will be re-using all of the vegetation that is being removed--some tree trunks will be used in or around the stream and everything else is being chipped to use as mulch around the Nature Center.

Getting Ready to Remove Vegetation

Today City staff, the contractor, and the construction manager walked the reach of the stream between the weir and the first place the trail crosses the stream downstream of the weir, talking in detail about vegetation removal. The contractor now knows what vegetation is to be removed and what is to remain. To let the equipment operators easily see what is to be done, bright paint was sprayed on trees that are coming out. In addition to removing a lot of non-natives (mostly Brazilian pepper and privet), these removals will open up the stream to sunlight, making it possible to grow shrubs below the tree canopy and further strengthening the stream banks.

Getting the Muck Out

I promised to write more about the muck, so today's post is all about muck. The first order of business in restoring the stream is to remove all the material that has accumulated on the bottom so we can create a more natural stream bed. If you have pulled out a branch that was stuck in this muck, you know that the stuff is sticky, gooey, and often smelly. The smell is from the decomposition that happens in an environment without oxygen (anaerobic decomposition). While there is some oxygen in the water, there wasn't much in the muck. But as I mentioned the other day, the muck doesn't smell. We let it dry out for a few days before we started removing it, and it appears that the drying got enough oxygen into the material to stop the anaerobic decomposition. This was really good news and has made this phase much more pleasant than it otherwise might have been.

We are spreading the muck in the undeveloped part of the Nature Center south of Willow Street. You can see it as you drive by from the eastbound lanes. The pile is about 4 feet high and covers about a half of an acre (as of this writing). Unless my math is bad, that's nearly 1,000 cubic yards. Later on, some of this might be mixed with sandy soil and recycled into the new stream banks.

What does the streambed look like without the water?

Now that the water has been drained out, a lot of the streambed looks like a wide, flat road. As the silt and muck has accumulated over the years, it has filled in all the nooks and crannies that were once there. What is left has almost no variation--no places for water to eddy or swirl, no places for fish to hide, no places where the water can speed up, no places for anything other than the shallow and slow flow from the north lake to the south lake. With no water covering it up, the evenness of the bed is remarkable.

I'm surprised that the muck doesn't smell really bad. After 30 years of anaerobic decomposition under the water, I was prepared for some pretty nasty odors. So far, the material that is being dredged out of the streambed just smells like mud. That's a relief!

Calling all mycologists

Here are some more examples of fungus found near the stream restoration construction site. Post IDs if you know what these are.

Name that Fungus

What is this? I assume it is a fungus of some sort. This photo was taken inside the construction area, downstream from the dam separating the stream from the lake, on the streamward side of the walking trail. The whole thing is about 1 foot in diameter.

Please Respect the Trail Closures

After years of planning and preparation, the Nature Center Stream Restoration is finally under construction. That means that the stream is now a construction site, and, as such, must be closed to the public. Rather than closing the entire Nature Center for the duration, we have closed only those trails that are within the construction area. We have put fencing across the trails at the closure points and put up maps showing which trails are open during construction. For everyone's safety, please respect these closures. When you are out walking the trails and you see a fence blocking the trail, please don't work your way around the fence to continue on the trail, even if other people clearly have done so. It costs us time and money to keep putting the fences back when patrons move them.

We can't put a fence all the way around the stream to cordon off the entire zone--too difficult, too expensive, and would damage too much of the vegetation. Instead, we are counting on every Nature Center visitor to cooperate with the trail closures and stay out of the construction zone.

So when you are out enjoying the beautiful natural environment, please keep your eyes open for construction signs and help us complete the stream restoration on time and within budget.

Critter Patrol

The stream has been draining since Monday. As it drains, we are doing everything that we can to make sure that no wildlife gets trapped by the receding waters. City of Long Beach staff, construction staff, and Nature Center volunteers have kept sharp eyes on the streambed for the telltale signs that animals may be in danger of getting stuck. A ripple on the water's surface might indicate a fish in a shallow pool. A small movement in the mud could be a crawfish working its way out. A tiny, muddy flip-flop could be a pollywog. All of these signs send the watchers reaching for their nets and buckets, to catch the animals and deliver them to the nearest lake. Hundreds of fish have been rescued, along with dozens of pollywogs, quite a few crawfish, and one turtle.

The rest of the stream water should be out by the end of the day on Friday. Then we will let the muck dry for a few days before the contractor begins taking it out. More about the muck in a future post.

Construction has begun!

Bright and early on the morning of Monday, October 5, 2009, the crew from Mike Bubalo Construction and PRM staff gathered at the Nature Center to start construction. The first order of business was to identify exactly where the trail closure fencing would go. Once those locations had been determined, Bubalo sandbagged the weir at the north end of the stream and built a dam at the south end to keep water from the lakes out of the stream. Later in the afternoon, Bubalo began pumping water out of the stream, over the dam, and into the south lake.