June 7, 2013 – Highwater Dredging into Cell 3

Dredge and Rainey Report
Highwater Dredging into Cell 3

June 7, 2013

Summary of accomplishments:

  • Most of Cell 3 is at marsh level
  • Total pump time this week = 5.75 hours
  • Total time pumped directly into Cell 3 (.366 acres) = 80.5
  • Total Time in Study Cells = 227.3 hours

Impediments: high wind and scattered showers

Summary:   Finally got to dredge!

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

Wednesday, June 5, 2013

Karen (I) came out the night before so witnessed a dawn promising rain. Timmy was working on the water well today. We had moved the pump, tanks, and all equipment to the pump shed, but the system had developed a leak, was sucking air, and not delivering water to the house. I couldn’t really do much to help, so decided to go to the dredge.

Figure 1. Sunrise clouds promised rain.

I made it to the dredge by 10:30 and began the process of hooking everything together. We were at the limit of the hose length and couldn’t dredge any further toward the main canal. All future dredging will have to be on the north side of the canal heading away from the main canal. This will increase the start-up and shut-down process, because the dredge will have to be moved back to the south side of the canal at the end of each day to be out of the way for safe use of the canal.

I tied the front and back of the Avocet to the side of the dredge (the dredge has no self-propulsion), loosened the side-to-side cables, pulled up both spuds and put the remote that controls one of the spuds where I could reach it from the boat. Very slowly, using the Avocet motor, I maneuvered the dredge to the north side of canal and dropped the spud when I got it where I wanted it. The winch cables are only 50-ft long, and are extended as needed by additional length of rope to the anchor points along the bank. At this position in the canal, the right cable needed to be adjusted so that the dredge could swing further across the canal, and the rope connecting it to the anchor had to be pulled off of the bottom and shortened. The process got me and my boat very muddy.

When I got back to the dredge, the water pump wouldn’t start, so I replaced the rusted red battery cable with a new copper one. I finally started the pump at 11:30 (Yay!) and began dredging to the north side of the canal, now “walking” it forward to the west. After about an hour, I stopped when the pump acted like it was clogged, with a drop in pump pressure. I pulled the pump up and cleaned it, tried to pump again, with the same result, so it was probable that the hose was clogged somewhere along its length.

A detriment of working alone, is that there is no way to watch the results at the pond of what is done at the pump in the canal. In order to check on the pumping status, I left the dredge pumping water and went to pond. Water was still moving out of the end of the hose, if only at a third of its volume, so wherever the clog was, it wasn’t complete and there was a chance I could pop it loose. I moved the hose to the south a bit to pull the curve out in case it was holding material at a kink or bend.

The water level was at 1.5″  above marsh level (+1.5” ML), and it was obvious by the difference in water color that there was no leakage of sediment into Cell 2 other than a tiny trickle adjacent to the dock. The higher water level, above the marsh substrate level, was allowing the overflow from the hose to move and filter through the surrounding marsh instead of trying to force its way through the containment. Perfect dredging conditions!

Figure 2. I pulled the outfall to the south to straighten the hose. It was obvious that there was no leak into Cell 2.

I was back on dredge by 1:00, spending only 15 minutes at the pond. Apparently, moving the hose and pushing water successfully loosened the clog, and the pump resumed at the appropriate pressure. After another 20 minutes, I had to stop to move left cable. I stopped again when pumping reached an hour to move the outfall again and verify that it was pumping correctly. We had found that it was best to move the hose every hour when the receiving basin gets shallow, to more evenly distribute the fill. I estimated we are within an inch or two of the targeted marsh level in the deepest parts of Cell 3. The water level at this time had increased to +2.5″ ML.

I dredged for another hour fifteen, and stopped to move the hose once again. The area north and east of the dock was fluid mud at +3″ ML. I moved the hose to point back toward the dock for the next dredging event to make sure that we filled the area around the containment where old leaks had occurred. However, when I texted Timmy and found that there was still no water at the camp, I decided to shut down now rather than dredge for another cycle making it 5:00 or later to make it back to the house.

I marked the rear left corner of the dredge with a bamboo pole so I would know where to start the next time.  I repeated the morning procedure and moved the dredge back to south side of canal, and secured everything for the night.

Figure 3. The last dredging of the day left fluid mud to +3" ML in the northwest corner of Cell 3.

Figure 4. The dredge was working the north (left) side of the canal. The main canal passes behind the dredge from left to right.

Thursday, June 6, 2013

After an evening with no running water (bottled water for cooking and drinking, melted ice in the cooler for washing dishes, and sponge bathing with a quart of water), Timmy headed to the boat ramp early to pick up a water well technician.

I headed straight to the pond to check the water level. Since it was still high at +3″ ML, the dredging opportunity was still open. Unfortunately, the sky was full of wet clouds, and I had to sit on the dredge for 15 minutes to wait for a passing shower. When the sky quit dripping, the dredge was moved to mid-canal, and aligned with the bamboo pole that was placed yesterday. It was 81° at 9:15, with a mix of sun and clouds. Showers came and went from the east to the west, grew bigger and meaner, and then moved back to the east again. I watched a waterspout develop and move off to the north.

Figure 5. The sky changed from sun to rain, to storms with waterspouts, and back to sun.

After an hour at 10:30, I stopped the pump to check the outfall and move it. However, when I walked out on the boardwalk, I could see the dark, rolling sky and hear crackling thunder – I headed straight back to the house to wait for heavy squalls to pass.

The radar cleared before lunch and I was back on the dredge at noon. Unfortunately, the waterpump wouldn’t start again. I wire-brushed and tightened all connections unsuccessfully. A trip back to house for sockets and battery cable, lost a nut – still wouldn’t start.  I texted Timmy for advice, but accidentally found a way to short it to start. Then, the right winch wouldn’t respond to the remote control switch, so I tried to test the connection with another remote. At 1:10, I started pumping anyway and manually pulled the cable to move the dredge.

Figure 6. The hose was moved to the center of Cell 3 after leaving chunks above the waterline at +3". No leakage was evident into Cell 2.

The sky was sunny and it was 91°. After an hour of pumping, I stopped at 2:30 to go ashore and move the hose. With the water level more than +3” ML, there was obviously plenty of material around the dock now, with fluid mud and chunks above the waterline. I was hoping that the fill would make it to the middle of Cell 3 as well, but it was difficult to make sure.  I pulled the hose as far as it would go into the center of the cell for the next dredging event.

Figure 7. Within minutes, the sunny sky was filled with storm clouds.

Before heading back to the dredge, I checked weather radar and discovered that there were some rather nasty looking storm cells moving my way. I was hoping to get another hour of dredging in before it made it this far and hurried back to the dredge. Timmy had been checking weather too, and he arrived, convinced me to change my mind, helped me shut everything down and moved the dredge over. Within minutes, the sunny sky turned gray and stormy, and we barely made it back to the safety of the house before water was shooting out of the sky in streams and deluges and the house was being buffeted by blasts of air.

This effectively ended the dredging opportunity this week, as the rain continued for the rest of the afternoon. I managed to find a big enough break to get back to the boat landing and head home without getting wet.



Karen A Westphal and Timmy J Vincent, National Audubon Society
Audubon Louisiana and the Paul J Rainey Wildlife Refuge
6160 Perkins Road, Suite 215, Baton Rouge, LA 70808
225-768-0921x202 office, kwestphal@audubon.org
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