Next Phase of Mouth-Bar Dredging Starting
The next phase of San Jacinto West Fork mouth-bar dredging should start December 1, according to Houston Mayor Pro Tem Dave Martin. This will start Phase 2 of a Texas Water Development Board grant announced in January of this year (although the phases were numbered differently at that time).
Small Strip of Bar Will Remain for Now
Contractors have already removed all but a few square feet of the above-water portion of the mouth bar. Only a tiny strip remains that will be used for safety purposes during the next phase.
“The dredge operator is using this land mass temporarily for safety reasons. The next phase will be mechanical dredging working off of floating barges. In the event that during the dredging process, a barge is damaged, the equipment can be readily offloaded onto the Mouth Bar land mass, preventing water damage to this equipment. We anticipate moving into the new location beginning December 1st,” said Martin.
Next Phase Includes Another 260,000 CY
Martin says the next phase includes dredging north of the area just completed (the above-water portion of the mouth bar) to a depth of six feet. See the black cross-hatched area below.
The numbers in the map above represent current depth in feet plus tenths of a foot.
- Purple numbers mean greater than six feet.
- Dark blue means five feet.
- Light blue means four.
- Green means three.
- And yellow means 2 or less.
More Mechanical Dredging For Next Phase
Martin says the next phase will consist of more mechanical dredging. That means more excavators working from pontoons. See pictures below.
Yesterday, two worked the edges of the area of interest.
A veteran dredger suggested they may be excavating test holes. Why? They could be looking to see how dense the silt is; that could affect the horsepower needed for hydraulic dredges in later phases.
They also could be looking for submerged trees. In a previous phase of dredging between West Lake Houston Parkway and the D1 marker below, dredgers ran into trees along the north side of the river, so they had to make up extra volume on the south side to meet objectives.
Photos Taken November 17, 2020
The Google Earth image below from last year shows where I photographed two dredges (D1, D2) yesterday in relation to where the mouth bar used to be.
Below: actual images of the dredging and dredge area.
In the picture immediately above, dredging in the next phase will take place in an arc around and behind that sliver of sand on the upper right.
Another Million Cubic Yards
Earlier in the year, the City announced that FEMA had agreed to dredge another million cubic yards. We do not know at this time where FEMA’s million cubic yards will come from. That might be yet another phase that dredges a channel between the dredges you see in the photo above.
Stephen Costello, the City’s flood czar, said in October that he was hiring an engineering consultant to determine the optimal course of action.
Posted by Bob Rehak on 11/18/2020
1177 Days since Hurricane Harvey