Monday, 24 October 2011

Sediment Pollution

It had rained quite heavily last night. 

I had thought it would be a good day to visit the parks and ponds.  But the sight that greeted me on my first stop was terrible.  Never mind that the grasses have had a mud wash in the deluge of muddy water and is looking half-dead but the pond is a murky, earthy yellow from sediment pollution.  The siltation and turbid water is the result of development on the hills further upstream leading to soil erosion when there is heavy rain. And there has been quite some rain in recent weeks and last night.

It is very disheartening indeed.

I could count barely a score of dragonflies buzzing around.  It practically broke my heart.  I had spotted a few rare species here before.  What will happen to the eggs they have laid and to the larvae?

The sight of even the most common of species was such a gift this morning.

Urothemis signata

Crocothemis servilia

Orthetrum sabina

I do think this construction project here is the culprit for the pollution downstream.....

With the removal of  the protective vegetative covering on these soils, loose sediments have been washed into the stream with surface water runoff when there is heavy rain.

This will definitely have a serious and adverse impact on the ecology and water quality in these streams and ponds.  The sediment will choke fish, plants and other life in these ponds.  Not only that, the sediment particles will also absorb warmth from the sun and increase water temperature. 

At the rate things are going, it would be very difficult and probably take a long time for recovery if it does happen.  Eventually, what we may have left is a degraded habitat void of healthy biodiversity.

I did not stay very long and went to another spot where I could sit next to a clear flowing stream.  The sounds of the gurgling water eventually calmed me down and the few dragonflies that flitted about brought some joy to my heart.

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