Saw this on The Engineering Network's website and thought to share here:



It’s the last half of October, the rains still pours like it was June. Even farmers didn’t ask for this much. Then Cameroon, wicked Cameroon opened up their dam. Oh damn. They‘ve had more than enough water to run their turbines. But here is Abuja, Kogi, Edo, Kwara, Delta, NIGERIA flooded. Help! Help!! Help!!! NEMA springs into action. Aaarrrgh. The deed’s done. Millions displaced.

“The Government is on top of the situation; measures will be put in place to forestall re-occurrence.”

Measures? While the Nigerian FG goes on to strengthen diplomatic ties with neighboring sovereign States and probably hold meetings with the heavens in a bid to talking someone up there into pouring less rains on our geographical space, the wise lives with the reality this new world presents, he does little things to protect himself, his family and his property from the floods, things as little as erecting SANDBAGS.

Yes sand! Present everywhere. Even the raging flood brings some more sands to you. “You could have curtailed my rage with these.” It seems to say. How many people however know the potency of sands as one big floodwater fighter?

Woven polypropylene sacs (BAGCO bags will do) filled with sands become useful armory for fighting floods. A barrier can be created with these sandbags as a flood mitigating measure. With a few simple calculations on the quantity of sand in each bag, number of bags required and the height of the barrier, all can go sleep in his property behind the sand bag barrier getting more assured than almost any government promised measures of prevention.

Quantity and Quality of Sand Needed

Fill every bag a little above half-capacity with sand. Sand is the easiest material for filling and shaping sandbags. Silt and clay in bags will form a good barrier, but working with those materials is more difficult.

Barrier Location

When selecting the location for the barrier, take advantage of natural land features that keep the barrier as short and low as possible. Avoid obstructions that would weaken the barrier. Do not build the barrier against a building wall due to the forces the barrier may place on the building. Leave at least 8 feet to maneuver between the barrier and buildings for observation, pumping seepage water and other activities.

Estimate Sandbags Needed

To get an estimate of the number of bags needed, note that a formidable wall is formed with a barrier base three times in length of the proposed height and a pyramidal/triangular formation for height more than one foot is better than a rectangular formation.
With those known, The U.S. Army Corps of Engineers recommends the following formula for calculating number of bags needed per linear foot of wall.
N = ((3*H) + (9*H*H))/2

N -- Number of bags required per linear foot of barrier
H -- Barrier height (feet)

It follows that for a 3 feet high barrier, the number of sand bags needed per linear foot of wall is 45.
N = ((3*3) + (9*3*3))/2 = 45

Therefore, if the wall is to be 100 foot long, get 4500 bags. You sure don’t have to wait for the floods to come before you start gathering.

Stacking Sandbags

Place the first layer of bags lengthwise on the barrier (parallel to the flow), lapping the bags so the filled portion of one bag lies on the unfilled portion of the next, with the tied or open end of the bag facing downstream. Offset adjacent rows or layers by one-half bag length to eliminate continuous joints, similar to what is done laying bricks. Compact and shape each bag by walking on it to develop barrier strength and create a tight seal. Continue to walk on the bags as succeeding layers are placed.

Sealing the Barrier

Cover the sand bike piles with plastic or cellophane papers and place on them one layer of sand to hold firm.

Disposing of Used Sands

They have done their jobs but have become contaminated. You can imagine rubbish that came with the floodwater. These sands should therefore be properly disposed of. They are not supposed to be used by children for play but would serve well for typical construction purposes.

Nobody's strong enough to stand upright under a flood of weak materials but sandbags could be made sturdy enough to stand against a flood in its rage.


Source and Pictures: http://go.engineer-ng.net/profiles/blogs/building-simple-sand-barriers-against-flood

This sounds like building the great wall. How about we encourage the dredging of the Niger.

Abeg forgive spelling. Phone typos.

saintneo: This sounds like building the great wall. How about we encourage the dredging of the Niger.

Abeg forgive spelling. Phone typos.

I think so too. Only the great wall is much more taller than what writer asks to build. Great advice, I think.

great piece, hilarious but educating.
A practical approach to flood mitigation

Truth be told is that dredging of the river niger and its tributaries was poorly done; that is why we are suffering this flood but instead our politicians are pointing to the release of water by Cameroon which is the greatest lie of 2012.