Sept 28, 2012 – Cell 3 half full

Dredge and Rainey Report
Cell 3 half full

September 28, 2012

Summary of accomplishments:

Repaired leaking hydraulic hose; oil change; replaced spud cable with SS;
Dredged 11.5 hours into Cell 3 this week
Total time pumped directly into Cell 3 (.366 acres) = 37 hours
Total time in study cells = 183.5 hours

Impediments: heat

Two weeks ago, the dredge hose was moved back along the canal bank by 40 ft, and in the 16 hours of dredging since then, we made it to the limit of its reach again. There are no spare sections to add, so before we dredge next, the entire hose configuration will need to be moved from the boardwalk to the northeast side of the pond.

Note: Google Earth has April 2012 photography of our dredge operations at:
Please Click On This Hyperlink to See the Study Area Map

Signs of fall continue: blue-winged teal are flocking together and circling, a pair of merlins were spotted this week and will probably stay the winter, the first vulture has returned from its breeding area elsewhere, and gulls and terns are losing their black hoods.

This report can be downloaded in PDF file format by clicking the Dredge and Rainey Report, Cell 3 half full hyperlink.

Monday, September 24

Our 17-ft boat, the Avocet, was launched at noon at the Intracoastal City public boat landing. As I was pulling up to the Shell Morgan dock for fuel, I saw Timmy just leaving. Since we don’t  have diesel at the dredge, I followed him back to the Rainey headquarters to pick up all the empty diesel cans I could find and unload my gear. By the time I was reloaded, I didn’t have time to make the round trip before our afternoon, Audubon Louisiana staff call. Timmy decided to come with me to drive while I listened in as best I could to save time. We had to cut the engine and drift when I needed to talk.

Back at the dredge, we unloaded all of the diesel fuel onto the dredge, and Timmy changed the oil on both the Crucial hydraulic unit and water pump. It had been over a year since its last oil change. This is not an easy task for either engine. The drain plug on the Crucial is in an awkward spot and a drain conduit has to be created each time. The heavy water pump has to be lifted up off the deck to drain it. We had plenty of sorbent pads on hand and managed the job with only a few drips of oil making it to the water. Timmy also reattached the repaired hydraulic hose to the pump. My job, of course, was to hand him things, which meant running around the dredge, back and forth to the boat where all the tools were. We put down plywood and a tarp this time to keep from losing anything through the deck grate.

Tuesday, September 25

The sun was late this morning, with sunrise close to 7:00 am. In two weeks, the sun moved from the left side of the island in our backyard pond to the middle, on its way to its winter rendezvous. We had gathered the day’s gear and headed out in both of our small boats by 7:15.

Figure 1. The sun continues its march to the south.

Figure 1. The sun continues its march to the south.

With the oil change out of the way, the next item of maintenance was replacing the left rear spud cable. The galvanized cable was rusting and showing signs of fatigue, so to avoid the nasty affair of trying to raise the spud with a broken cable (see May 8), we changed it out to stainless steel (SS) while it was still connected. This involved laying the 24-ft spud down on the deck.

The spud has two pins that hold it upright, one underwater. Timmy pulled his boat around to the stern to reach them, while I climbed our little step ladder to tie a rope around the upper handles. Using the winch, I raised the spud out of the mud and pulled on the rope from the bow of the dredge, until I could get it to rotate against the A-frame of the dredge. Then it had to be lowered to go under the frame, which meant it was pushed back into the mud and would no longer rotate. Timmy got on top of the Crucial unit and I took the remote control into my boat that was tied alongside. With the boat pushing on the dredge to rotate it and Timmy pushing on the spud, we managed to get it under the frame and pulled down onto the deck.  The old cable was stripped out and the new stainless steel cable was attached and threaded onto the winch. To stand the spud back up, the process was reversed, and new stainless steel cotter pins were inserted into the spud pins. Now the only cables that aren’t SS are the left traveling cable and the pump cable.

Figure 2. Left: Timmy working to attach the new SS cable to the winch. Right: To replace the rusty cable on the spud, it had to be laid on the deck.

Figure 2. Left: Timmy working to attach the new SS cable to the winch. Right: To replace the rusty cable on the spud, it had to be laid on the deck.

Figure 3. The hose float had to be cleaned of barnacles before we could use it for the outfall.

Figure 3. The hose float had to be cleaned of barnacles before we could use it for the outfall.

The last time we dredged, we had to deal with a sunk pontoon which was extremely difficult to move and impossible by hand. So this week, we took a float off of the canal-side hose to put on pond-side outfall. The float was encrusted with barnacles and slippery algae, and it took the two of us a good 45 minutes to clean it off where we could handle it without getting cut up. Timmy smashed and scraped with a piece of wood and I smashed and washed with my boat brush.

Luckily, the partially sunk pontoon was close to the pond shore and the water level was low  (-1.5” below marsh level), so that a piece of plywood on top of the soft mud could be used to reach it. Both of us worked to get the connection loose. Since there was no slack to pull it apart, I hammered on the connection while Timmy pulled on the brace that kept the hose on the pontoon from slipping. Once it was free, I tied the loose end of the pontoon rope to the free end of the muddy hose and we pulled it ashore to attach the orange float. I walked the rope around to the marsh on the other side to see if it was long enough still attached to the pontoon. However, when I tried to pull it, the very first tug landed me on my back in the thick marsh – my hasty knot had pulled free!  After extracting myself, I headed back to the pontoon, where I had to feel around in the mud to untie the other end of the rope, and Timmy tied the next knot onto the hose.  We walked the rope around the marsh again to pull the float to a new position, this time successfully.

Figure 4. The hose was disconnected from the pontoon, a float attached, and the end of the hose was pulled into a new position.

Figure 4. The hose was disconnected from the pontoon, a float attached, and the end of the hose was pulled into a new position.

By this time, it was getting hot – it was 98° degrees on the thermometer in the sun, so we were happy to get back in the shade of the dredge canopy. To make sure everything was working properly after all of our maintenance work, we dredged for an hour and a half. I made one trip to the pond after about 45 minutes and pulled the outfall over a few more feet to spread the effluent. Our end of the day visit to the pond showed that the effluent had made a nice delta to marsh level, and the mud plume had circled Cell 3 in a counter-clockwise rotation all the way past the dock and along the containment.

Figure 5. The plume from the outfall circled the cell to the north and west along the dock and containment.

Figure 5. The plume from the outfall circled the cell to the north and west along the dock and containment.

It was just too hot to continue, and we had spent 8 hours working, so we shut down the dredge for the day, and headed back to the house. After we and the day cooled down a bit, we headed out to Vermilion Bay to shop for supper. We found a great area referred to us by some friendly gulls, and came away with a cooler of speckled trout.

Figure 6. A successful shopping trip to Vermilion Bay landed us speckled trout for supper.

Figure 6. A successful shopping trip to Vermilion Bay landed us speckled trout for supper.

Wednesday, September 26

Dawn found us in Christian Marsh to survey the waterfowl population and review the vegetation plantings along the terraces. Sitting quietly in a blind, an amazing number of common gallinules (moorhens?) could be counted as far as you could hear. I almost dropped my binoculars when a least bittern called from the reeds at my feet. Red-winged blackbirds and grackles tried to land on us before winging away in startlement. Summer and black ducks passed over, as well as numerous flocks of blue-winged teal that Timmy said were staging for their southern crossing. Double crested cormorants, great egrets, snowy egrets and roseate spoonbills also floated across.

On our ride back, we passed the terraces that had been constructed and planted this year, and observed a range in the success of the vegetation. Some of the terraces showed very healthy, dense stands of spreading smooth cordgrass (Spartina alterniflora), others were somewhat spotty.

Figure 7. Dawn from a duck blind, and thick marsh grass on a terrace that was a result of a planting project this summer.

Figure 7. Dawn from a duck blind, and thick marsh grass on a terrace that was a result of a planting project this summer.

Back at the house, I had to work on an overdue article for Wingspan, and Timmy took care of some of his manager duties. I sent off a draft and packed up my computer with the rest of the dredge gear to work on it onboard the dredge.

I headed out by myself to get the dredge prepped. At 12:30 the water level in the pond was right at marsh level. The sky was partly cloudy, and the temperature measured 95° in sun and a comfortable 88° in the shade with a light breeze. With a beach umbrella set up to block the southern sun, I started dredging just before 1:00; and Timmy arrived about 30 minutes later. It took about 35-45 minutes to dredge across the canal. The new hydraulic winch is operated by a shunt valve that automatically shuts the pump off when the pump is raised or lowered. This is more efficient at moving sediment as there is less time wasted pumping just water.

Timmy dredged and I multi-tasked – I operated the side-to-side winches, kept the water pump fueled and swapped out the spuds while working to refine the article on my laptop. Since I was focused on composing, he did have to occasionally remind me to move the dredge, and seemed to get a lot of amusement out of whistling at me over the engine noise and watching me jump!

At 3:30, Timmy used the Avocet to move the left traveling cable back to another tree along the bank, and took a trip to the pond where he moved the outfall around. Pete Lege came down the canal to check the alligator lines on his side of the canal and I had to let the right traveling cable down so that he could pass. Around 4:30, Timmy left to head back to the house, and I stayed to dredge one more roundtrip across the canal.

I noticed huge splashes down at the bend of the canal, dug out my binoculars, but couldn’t figure out what was causing it. I thought perhaps a large alligator had been caught on one of Pete’s lines, but the splashes were too widely scattered. I continued dredging and watching. I finished my line at 5:30, shut down the dredge and loaded the boat, and the splashes were still ongoing, so I drove down to the area and shut off the motor. No splashes. I drifted, a few small fish jumped, a small gator cruised along the bank, a gar rolled. No splashes. I have no clue what was making 3-ft splashes for over an hour, but clearly there was a lot of feeding going on. Timmy
suggested it might have been sharks, because alligator gar (as I thought it might be)don’t usually feed together in a group.

I couldn’t leave without checking the pond, so headed back to the dredge site and tied off my boat. As I walked the trails to the boardwalk, I could hear a commotion in the pond. There was a congregation of over a dozen snowy egrets in the fresh mud just to the northwest of the outfall that were squabbling over fishing rights, with a couple of tri-colored herons and grackles looking on. As we pump mud in, it concentrates the minnows and other aquatic creatures into the decreasing areas of water, making fishing easy. They finally noticed me as I stepped up on the boardwalk and scattered to the four winds. The grackles and tri-colored herons are more tolerant and just moved over to the Cell 4 walkways. As I walked the boardwalk, I also spotted a common gallinule in Cell 3 darting under cover, and a large alligator cruising next to the outer containment. A flock of teal I had not noticed burst from behind an island and took off to a quieter neighborhood.

Figure 8. Over a dozen snowy egrets were squabbling over fishing rights in the fresh mud. The outfall was on the other side of the marsh island behind them.

Figure 8. Over a dozen snowy egrets were squabbling over fishing rights in the fresh mud. The outfall was on the other side of the marsh island behind them.

Figure 9. Large alligator cruising just outside of our outer containment.

Figure 9. Large alligator cruising just outside of our outer containment.

Thursday, September 27

Sunrise was at 6:56 am. We went to the pond first to move the outfall float to the west. The water level had come up slightly to about an inch above marsh level. The cumulative result of pumping had developed a nice delta complex along the southeast section of Cell 3.

Figure 10. The southeast section of Cell 3 is fairly full with a delta complex above marsh level. This view is to the north from the walkway at 5a.

Figure 10. The southeast section of Cell 3 is fairly full with a delta complex above marsh level. This view is to the north from the walkway at 5a.

Figure 11. The dredge operators: Timmy with the pump control, Karen with the side-to-side controls.

Figure 11. The dredge operators: Timmy with the pump control, Karen with the side-to-side controls.

By 8:30 we were back on dredge to prep and get started. It was 76° in the shade, fair, and breezy. At 9:20, Pete came by to pick up two alligators on his lines. Alligator season will close soon and he was picking up lines as he went. As soon as he had come and gone, Timmy left me dredging to go to the pond to move the outfall. The hose had been too difficult to move with the thick mud above the water level and he thought it might be easier once we had pumped some water and fluid mud in to help the hose slide. With the fill up to marsh level in the area we were working, he wanted to move the outfall every 30 min to an hour to spread the denser material.

After lunch, he went to the pond and was gone for over an hour. I was beginning to think I would have to go look for him and was envisioning him stuck headfirst in the mud. However, he did return, and reported moving the outfall several times and leaving it looped over itself. After 5.5 hours of pumping, we had to stop, as I needed to leave this afternoon and needed time to clean up and pack up.

We went back to the pond to view the results of this week’s effort. The fluid mud looked to be at least half of Cell 3 with multiple deltas above water level, which was itself 1.5 inches above marsh level. With a total of 37 hours, we were right on schedule for a half-full cell. We had some muddy water escaping from the containment right at the dock, but we determined this to be a minor flow that was going into Cell 2 anyway. More muddy water was backflowing into Cell 5 through containment 5a, but this was expected and also a benefit.

It was nice to leave knowing that Cell 3 was half full. October is a full month of meetings and other activities, so I’m not sure when we will be able to dredge next.

Figure 12. Cell 3 was determined to be half full after a cumulative result of 37 hours of pumping. Fluid mud is past the islands in the center. The view is to the north-northwest from the walkway at 5a.

Figure 12. Cell 3 was determined to be half full after a cumulative result of 37 hours of pumping. Fluid mud is past the islands in the center. The view is to the north-northwest from the walkway at 5a.

Figure 13. This is an estimated status of the study cells as of September 28, 2012. Green lines are containment, orange line is a planned containment, dashed blue line is the hose configuration in the pond, yellow lines are the boardwalk and walkways, white dots represent the positions of PVC marker poles.

Figure 13. This is an estimated status of the study cells as of September 28, 2012. Green lines are containment, orange line is a planned containment, dashed blue line is the hose configuration in the pond, yellow lines are the boardwalk and walkways, white dots represent the positions of PVC marker poles.

Karen A Westphal and Timmy J Vincent, National Audubon Society
Louisiana Coastal Initiative and the Paul J Rainey Wildlife Refuge
6160 Perkins Road, Suite 215, Baton Rouge, LA 70808
225-768-0921 office, kwestphal@audubon.org

 

This entry was posted in Dredge Reports, Marsh Restoration, The Paul J. Rainey Wildlife Sanctuary. Bookmark the permalink.