Brown water
After something of a dry spell, during which I was able to drive my truck out of the yard without sliding about, there’s been a lot of rain lately. My truck is back to sliding, but that’s a minor issue compared with what happens to all that rainfall.
What happens is that the rain hits the land and runs downhill. It channels into dry gullies. If the rain is heavy enough, flash floods occur and wash all before them – dirt, rocks, trees. But any kind of heavy or prolonged rain will wash earth and debris down the gullies. All those gullies lead to the ocean, channeled under roads by culverts (bottom photo).
When the runoff reaches the ocean, it forms a distinct area of dirty brown water in the blue Pacific Ocean (top photo). The contrast is striking and easily visible from miles away. Over time, the brown and blue water will begin to mix until the delineation is gone, but part of that process is the dirt from the brown water settling to the ocean floor.
This kind of runoff is one of many threats to coral reefs around the Big Island. It’s not just dirt in the runoff, but also pesticides and other chemicals that can be washed down into the reefs, damaging the coral. There are hundreds of gullies and only a few places have erosion prevention measures to help mitigate this pollution.
So while Hawaii may be considered paradise, it has its share of challenges. And the problems associated with runoff and pollution are more visible and obvious than most.
Posted in response to this week’s Friendly Friday challenge on the theme of ‘Contrasts.’ See more responses here.
The photo illustrates the problem most graphically.
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It’s a very visible problem, that’s for sure.
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This is quite a common problem now. All the pesticides put into the soil are mixing with the rivers and seeping into the water table. Of course it then ends up in the sea. Just another thing we are doing to kill off our oceans.
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Sad, but true.
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Wow. The runoff is really in stark contrast to the deep blue of the ocean. I didn’t realize about the pollution and chemicals. So sad.
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It is unfortunate and it’s a big task to control all the runoff into the ocean. Don’t think it will happen in my lifetime.
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Oh…
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Fantastic post, Graham. AndI live the environmental aspect of your post. Dirty runoff is a worrying threat to the coral reefs of Australia too, especially with large scale industry, heavily fertilised agriculture and mining abutting the coast whet the reef grows and some actively discharging effluent into the sea.
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Thanks. Quite how the coral survives these days, I don’t know, but it seems to be hanging on. There are so many threats, the runoff issue is low on the list. The corals that can adapt the best will be the ones that survive.
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Darwin would are with that!
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Darwin would agree with that!
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I was going to say that too!
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Sadness! 😔
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Yes it is. An identical patch appeared today after more rain.
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😕
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