February 8, 2013 – Resume Dredging

Dredge and Rainey Report
Resume Dredging

February 8, 2013

 

Summary of accomplishments:

  • Most of Cell 3 is at -1” ML or better
  • Pumped for 4.75 hours into Cell 3
  • Total time pumped directly into Cell 3 (.366 acres) = 64.5 hours
  • Total time in study cells = 211 hours

Impediments: low water in the pond and canal

This report can be downloaded in PDF file format by clicking the Dredge and Rainey Report, Resume Dredging hyperlink.

Summary:
This week was the first time we could dredge since December 5, 2012. Winter fronts have kept water levels low in the canal and/or the pond, or it rained for weeks at a time, preventing us from finishing Cell 3.

Tuesday, February 5

Timmy was tied up in town today, so I brought myself out in the Avocet and made it to the house by 10:00. Timmy had told me the water levels might be good for dredging, so I unloaded my gear and replaced it with dredge gear. By 10:37, I was at the pond. An adult brown pelican eyed me from the outer containment, and 3 black-necked stilts nervously stalked across the mudflat in Cell 3.

Figure 1. At the pond, I was greeted by a brown pelican on the outer containment and 3 black-necked stilts in Cell 3.

Figure 1. At the pond, I was greeted by a brown pelican on the outer containment and 3 black-necked stilts in Cell 3.

I was disappointed by the water level when I got there. There was plenty of water in the canal, but it hadn’t made its way through the marsh to the pond yet, and it was still 3” below marsh level (BM). I could see by the wet/dry contact that it was on its way in. Perhaps an hour or two would bring it up enough. I took my time admiring the new vegetative growth and taking pictures.

Figure 2. Pond water level was at -3" ML.

Figure 2. Pond water level was at -3" ML.

Figure 3. Wasps were again in the forward battery box.

Figure 3. Wasps were again in the forward battery box.

By 11:00, I was on the dredge. Since it has been 2 months since we last dredged, I thought it would be a good idea to run all the engines whether I dredged or not.

The battery box for the traveling cables was once again full of wasps, and I needed to connect the wires for the winches. Using a long stick, I lifted the lid and then sprayed it down with wasp killer. While waiting for the wasps to clear out, I started the hydraulic unit and lifted the pump off the deck.

The water pump wouldn’t even try to start. Upon inspection, the battery cables were corroded, so I loosened them up, wiggled them around a bit, and tightened them down again. The water pump started and I pumped water through the hose to clear it. When the water was turned on for the pump jet-ring, most of the jets were clogged. I got out a drill-bit of an appropriate size and used a hammer to tap it into each jet nozzle while the water was on slow. I had to do this several times before I could get most of the rust-crud to flush out.

Figure 4. The jet-nozzles had to be cleaned out before the jet-ring was ready for use.

Figure 4. The jet-nozzles had to be cleaned out before the jet-ring was ready for use.

The tractor drive (that moves the pump forward and back) wouldn’t work at first. The buttons on the control elicited no response. As I was winding up the control cables, I pushed it again and the pump moved. Apparently, there is a loose wire and the control will only work if hung up a certain way. With everything working, I hesitated. Surely it wouldn’t hurt if I dredged for just a little while? It had been an hour or two, water was headed into the pond, and there was good water level in the canal. I couldn’t resist. I pulled out the chairs, dropped the pump, and started pumping.

I dredged for about a half hour when the left traveling cable control hung up and the cable broke. I continued dredging to the right for another half hour. When it was time to start the swing back to the left, I put everything on pause while I got in the boat and fixed the cable, retying it to a tree. I finished the swing to the left and shut the dredge down so I could go to the pond.

As I had feared, the pond water level had not increased enough to prevent the water pressure from forcing exits under the containment. There was an amazing amount of fluid mud in Cell 3 and a nice delta at the outfall, but the water level had not come up so the fluid mud only raised the level to -2” BM. Cell 2/1 was obviously receiving huge amounts of sediment as well, with deltas showing near the dock and marsh, and significant flow burbling under the plywood containment. However, the heavier material was staying in Cell 3, and I thought it would be worth another delta.

Figure 5. Fluid mud to 2" below marsh and a new delta at the outfall with just an hour of pumping.

Figure 5. Fluid mud to 2" below marsh and a new delta at the outfall with just an hour of pumping.

Figure 6. Cell 2 (right) was full of suspended sediment escaped from Cell 3. Exposed mud of Cell 4 is to the left.

Figure 6. Cell 2 (right) was full of suspended sediment escaped from Cell 3. Exposed mud of Cell 4 is to the left.

I untied the rope to the hose and moved the outfall over. As I was tying it off, I noticed a marsh hawk (northern harrier) hunting along north pond marsh, so intent on the ground that she didn’t seem to notice me.

Figure 7. Marsh hawk (northern harrier) hunting the marsh along the north end of the pond.

Figure 7. Marsh hawk (northern harrier) hunting the marsh along the north end of the pond.

I returned to the dredge, and saw Timmy pass down the main channel on his way back from town.  The tide was coming into the canal with a strong current, and the water level in the canal was up a foot from this morning. I restarted the dredge to finish the dredge swing, but I didn’t quite make it to the south side before the left traveling cable broke again. The dredge was in a good position to leave it where it was, so I shut everything down and secured it for the day. When I was packed up in the boat, I didn’t try to fix the broken cable, but tied a rope to shore to keep it from drifting out of line.

A trip to the pond showed a second delta as a result of the last event and fluid mud pushed up onto the surface at the south end of Cell 3, filling in some of the mud cracks that had formed there, and adding another layer to the fill.

Figure 8. Two deltas from today's dredging show at the top left of the image and fluid mud is evident throughout the pond.

Figure 8. Two deltas from today's dredging show at the top left of the image and fluid mud is evident throughout the pond.

Wednesday, February 6

The morning started with a light fog that softened the light and sounds of the awakening landscape. A scattering of ducks and wading birds flew past in the cool air. As the sun rose, I watched through binoculars as three deer crossed, one by one, from the marsh to the safety of the tree-covered island.

Figure 9. Morning color.

Figure 9. Morning color.

Figure 10. One of three deer crossing between marsh islands in the early light can be seen in the suns reflection.

Figure 10. One of three deer crossing between marsh islands in the early light can be seen in the suns reflection.

This week we were scheduled to conduct a shorebird survey, and the weather/tide conditions dictated that this had to be the day. Erik Johnson, Audubon Louisiana’s Director of Bird Conservation, had planned to come out, but had to be in Grand Isle instead. Timmy loaded the 4-wheeler and trailer onto the Goose and by 7:30 we were on our way down the canal to the chenier and beach.

Figure 11. Water hyacinth and trash covered most of the beach.

Figure 11. Water hyacinth and trash covered most of the beach.

By 8:00, we were on the beach. It was very windy and cool, the tide was up, and recent rains had flushed water hyacinth out of the water ways into the Gulf nearshore area. The beach was thickly covered by water hyacinth and trash, obviously deposited in several onshore events. Very little of the beach was exposed.
We headed west at first, but the birds on the small amount of exposed sand flat were too active and staying just out of reach of good binocular view. We decided to head toward Audubon property to the east instead.

There really didn’t seem to be many shorebirds other than Sanderlings, or any birds at all, as we trundled around the trash and water hyacinth raft. A Ringed-billed Gull here or Herring Gull there, a few Savannah Sparrows and lots of Sanderlings. We were becoming concerned that our count wouldn’t reflect the obvious value of the Rainey Wildlife Sanctuary beach.

Things started to get interesting as we made it to the area sheltered by the breakwaters. Wave refraction and currents do strange things to the sediment around breakwaters, creating circular embayments with high beaches, separated by tombolos of sand that sometimes connects the breakwater to the beach. With the high tide, each isthmus is submerged creating sheltered islands behind the rocks.

Figure 12. A stilt sandpiper was actively feeding in water up to its belly and dipping its head all the way under water.

Figure 12. A stilt sandpiper was actively feeding in water up to its belly and dipping its head all the way under water.

Gulls, terns and pelicans seemed to enjoy the wind-shelter of the tiny beaches adjacent to the rocks. A Snowy Egret fished next to a very active shorebird that was up to its belly in the water, sticking its head all the way under water. That turned out to be a Stilt Sandpiper, with its behavior described perfectly in the field guide.

As we set up the scope and were checking out the smaller birds on one tombolo, I spotted a rather odd looking jumble on the next one that looked like large bubble wrap or a lumpy carpet from this distance. The scope revealed it to be two tightly packed groups of Sanderlings mixed with plovers – a lot of them! More plovers were actively feeding spread out over the limited beach. Knowing that they were likely to leave as we approached, we did a quick count of 75 Piping Plovers and 150 Sanderlings. Then I realized there were Dunlins mixed in, and subtracted them from the total.

We got off the 4-wheeler and bush-wacked through the roseacane and rattlebox to move closer and try not to scare them off. I took a more pictures and we did another count from a different direction, with the same numbers. Later, looking at the pictures with Erik Johnson, we determined that some of the plovers were Snowy and Semi-palmated. Total plover counts for the day were 63 Piping Plover, 4 Semi-palmated Plover, 2 Snowy Plover, 3 Wilson Plovers and 12 Black-bellied Plovers. Not too bad!

Figure 13. Two groups of small shorebirds looked like bubble-wrap or a fuzzy carpet from far away. Black-bellied plovers and ruddy turnstones were on the rocks to the right.

Figure 13. Two groups of small shorebirds looked like bubble-wrap or a fuzzy carpet from far away. Black-bellied plovers and ruddy turnstones were on the rocks to the right.

Figure 14. Plovers everywhere!

Figure 14. Plovers everywhere!

Further down the beach to the east we spotted flocks of Lesser Scaup, White Pelicans, Royal Terns, Caspian Terns, Forster’s Terns, Killdeer, and others. Almost completely camouflaged by water hyacinth, a dead dolphin was rocking in the surf zone. We would have to call that in.

By the time we made our way back from the end of the driveable beach, the tide had come up even more and the wind had picked up. We decided the west beach could wait for another day.

Thursday, February 7

It rained all night, and at dawn the sun struggled to peek under the thick cloud cover. The clouds won. The water level in the canal had been up for a while, so we expected water level in the pond to be up as well. Both small boats were loaded and on the way to the dredge site before 8 am.

Figure 15. Sunrise was a brief glimpse under dense overcast.

Figure 15. Sunrise was a brief glimpse under dense overcast.

The canal water level was at 1 ft so there was plenty of water for the dredge to operate. I was elated to see that the pond water level was at +1” above marsh level (ML). However, the deltas I had made two days ago were below water, once again showing that we needed elevated water level to fill the cell. It was cool, overcast and humid, but now was the time to dredge.

Figure 16. Overcast, 60°, and a light breeze made it a bit chilly on the open deck of the dredge.

Figure 16. Overcast, 60°, and a light breeze made it a bit chilly on the open deck of the dredge.

I went to untie the west pull rope to the outfall and Timmy walked around the marsh to untie the east pull rope. While he was positioning the outfall, I headed back to the dredge to fix the left traveling cable that had broken day before yesterday.

Timmy joined me to get the dredge set up and we started dredging as close to the south bank as we could. The day stayed overcast, around 60°. After an hour, we reached the north end of the swing and Timmy headed to the pond to monitor the flow and to move the outfall around.

The water in the canal was dropping quickly, already 10 inches below what it was when we started 2 hours ago. The remote control on the left winch started hanging open, which caused the rusted cable to break when it overstretched. By myself, I had to put the dredge on pause, get in the boat, tie the broken end of the cable to the boat and pull it to shore where it could be reconnected. Then it was back to the dredge, engage the pump and continue pumping.

Timmy returned after moving the outfall several times and hearing the dredge motor noises change. After only 30 minutes, the left cable broke a second time. The canal water level was getting too low to dredge anyway. We flushed the pump and secured the dredge, then headed to shore.

Fluid mud was brought up to the water level at +1” ML with two deltas evident near the dock. A lot of material had escaped into Cell 2, but not nearly as much as two days ago when the pond was at -3” ML. The flow spreads out and slows when it can move into the marsh and doesn’t tend to concentrate in powerful under-containment scouring channels, so more of the material can drop out of suspension before draining from the cell.

Figure 17. Two deltas near the dock were evidence of the material we had moved in 2 hours.

Figure 17. Two deltas near the dock were evidence of the material we had moved in 2 hours.

With Timmy trying to move the hose by himself, the hose had looped over itself and needed to be unwound. Timmy walked the marsh to pull the hose around to the east, and I walked the walkway for the west rope, to continue the swing of the hose end to the south and west. The small rope was hurting my hands, so I had it wound around my body where I could use my weight to pull. Feeling a bit shakey on the narrow walkway, I worked my way over to the marsh island as I slowly pulled with my body then took up the slack in the rope for the next pull.

Timmy had continued walking around the marsh to come help, but hadn’t reached me yet when I felt the rope pop. I let out a yelp – and suddenly I was on my backside in Cell 2! Luckily, I was wearing waterproof pants and boots, and had landed just on the edge of the marsh island. Though my outside was covered in mud, none of it had made it to my skin. It could have been much worse! I managed to get myself back onto the walkway before Timmy could get to me to help, and by that time we were laughing so hard it was difficult to stay balanced again on the 10” wide planks. Had I been just a foot further over, the story would have been a lot different (the fill mud was about 12 inches deep over more mud there). The rope had not broken, but popped a loop off the end of the hose – just enough to get me overbalanced… We decided that the outfall was perfect where it was and tied it off.

Figure 18. The hose was set for the next time.

Figure 18. The hose was set for the next time.

I returned later that day when the sun came out and Cell 3 had time to settle some. The two new deltas were very evident and the fluid mud had settled with about a quarter inch of water on top. We had added a layer of sediment to the earlier fill so that the mud cracks at the south end were smoothed over a bit. I can’t wait for the next time the water level is above marsh. It should only be a few more hours of dredging to fill it completely.

Figure 19. When the water level in the pond dropped by just a half inch, the two new deltas near the dock were exposed.

Figure 19. When the water level in the pond dropped by just a half inch, the two new deltas near the dock were exposed.

I took my usual tour of the site and admired the new vegetation. Savannah Sparrows were everywhere, and I spotted a Sora wandering in and out along the marsh edge. I sat still long enough for it to wander out again for a portrait.

Figure 20. The marsh vegetation spreading into the south end of Cell 3 and a Sora looking for dinner at the north end.

Figure 20. The marsh vegetation spreading into the south end of Cell 3 and a Sora looking for dinner at the north end.

Figure 21. The dredge "John James" in afternoon light.

Figure 21. The dredge "John James" in afternoon light.

Figure 22. Coming "home" after a long day.

Figure 22. Coming "home" after a long day.

Friday, February 8

Figure 23. Another foggy morning at the Paul J Rainey Wildlife Sanctuary.

Figure 23. Another foggy morning at the Paul J Rainey Wildlife Sanctuary.

We had reported the deceased dolphin found on the beach during the bird survey on Wednesday, and Timmy had made arrangements to retrieve it. While he took the Goose through the early morning fog to pick up a vet and Sandy Maillan from the Department of Wildlife & Fisheries in New Orleans, I went to the dredge to fix the broken left cable. The fog and cool temperatures made the boat ride a bit chilly.

At the dredge, the water level was too low for me to get to the bank where the left traveling cable was tied. I stripped the old, rusty galvanized cable from the left winch and cleated it off to keep the dredge attached to the shore. I had prepared the new stainless steel cable the night before by adding a loop guard to one end, and added a “see-me” float before attaching it to the winch. I carefully and neatly wound the new cable onto the spool and hooked the loop around the deck cleat to keep it tight.

Figure 24. The new stainless steel cable and block.

Figure 24. The new stainless steel cable and block.

Then I realized I hadn’t run it through the deck block. I hadn’t intended to use the old block anyway, as it was bent, rusty, and the cable kept getting caught in it. I had to search for the stainless steel block I had bought some time ago in anticipation of this change-out. It wasn’t in my dredge gear on board the dredge but back at the camp in Timmy’s newly reorganized workshop.

Luckily, the block could be taken apart, so I didn’t have to undo my neatly wound winch to get it threaded through. I added a new rope, and tied it all down so it would be ready to use the next time we could dredge.

Figure 25. The old rusty cable and blue rope still tied the dredge to shore, and the new stainless steel cable and yellow rope are set and ready to go.

Figure 25. The old rusty cable and blue rope still tied the dredge to shore, and the new stainless steel cable and yellow rope are set and ready to go.

All of the winches, except the pump, have stainless steel cable now. With that task done, and conditions not right for dredging (low water), I headed back to headquarters to pack up for my trip home.

Since I wasn’t in any hurry to leave, I texted Timmy to see if they had retrieved the dolphin yet. I wanted pictures of the crew if I could get there in time. He reported that they were still working on it. I hurried down the canals to the south end of our property then over to the chenier and the beach access landing. This is private property and not Rainey, and I don’t have permission to cross it without Timmy, so stayed in the boat to wait.

After a long while, Timmy arrived towing the dolphin, but he had had to leave the trailer and the people back on the beach. It was going to be at least another hour before everyone would be back at the boat, so I opted to head home instead. I was disappointed that I didn’t get to meet the dolphin response team.

Figure 26. Retrieving a deceased dolphin for the LDWF.

Figure 26. Retrieving a deceased dolphin for the LDWF.

 

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

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