Sand boil pops up as Mississippi River levels remain extremely high

Sand boil pops up as Mississippi River levels remain extremely high

BATON ROUGE, LA (WAFB) - A sand boil has popped up near the Mississippi River as water levels continue to be extremely high.

(Source: WAFB)
Sand boil popping up near Mississippi River not a cause for concern

The sand boil is located under the I-10 bridge along River Road. City officials have placed sandbags around the boil, which is about 6 feet across, to contain the water. The boil is about 80 feet from the toe of the Mississippi River levee just under the bridge.

When the river gets extremely high, like it is now, the weight of the high water adds pressure, which pushes water through the soil layers under the levee. If the water can find a weak spot in the soil layers, it seeps to the surface. If it can find an especially weak spot, it may actually bubble, or boil, to the surface.

(Source: WAFB)

This is a very small boil, at least for now. It appears the Department of Public Works is proactively surrounding this boil with sandbags given that the river level is expected for remain high for weeks to come, however, this boil could get more active as time goes on.

Seepage along the lower Mississippi this spring is potentially becoming a bigger issue than it was during 2011, when the water was slightly higher than it is now.

The main reason for the added seepage is largely because the river has been unusually high since late September/early October (a time when hydrologically, the Mississippi is normally at it’s low point of the year), and has been above the “archaic” 35-foot flood stage since early January. Given the latest forecast, we are on target to possibly endure the longest run of water above 40 feet in at least 25 years.

Anyone who travels along River Road may notice a number of things:

  • Ditches are just about full. Yes, there have been a good number of rain days recently, but rain amounts have been below normal. These ditches are reflecting under-levee seepage.
  • Pastures are soft/soaked and there’s standing water around the subdivision currently under construction just below Farr Park (BREC Horse Farm) from seepage
  • Of course there are the usual issues in places like the Riverbend subdivision, but the Levee District says they’re getting seepage comments/complaints from places never reported before
  • Grass cutting on the levees may be limited to the upper half, keeping the tractors off the softer soil near the levee’s base

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