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the falls was flowing like normal when I was there Thur AM...
save our indigenous and endemic Hawaiian Plants... learn about them, grow them, and plant them on your property, ....instead of all that invasive non-native garbage I see in most yards... aloha
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save our indigenous and endemic Hawaiian Plants... learn about them, grow them, and plant them on your property, ....instead of all that invasive non-native garbage I see in most yards... aloha
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quote:
Originally posted by bystander
I seem to recall it being said that this is an el nino year. The winter is supposed to be drier and cooler. I've noticed the lack of rain for the last few weeks. Before that, someone on this forum was comlaining about the rain.
according to the surf forecasters, this is neither an el nino nor la nina winter.
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The flow has been at 13 CFS for the last 2 readings, vs the median of 264 CFS -& 25th percentile at 40CFS, granted it is not at the low recorded of 6.5 CFS or '78, bit is way closer to the lowest flow than even the 25th percentile flow, so I'm gonna guess that the flow was not 'normal' on Thurs...
Some posters may not even know that the Wailuku at Rainbow Falls is partially diverted, as there is a Hydro penstock above the falls. During lower flow, water is diverted at 10% of flow rate to run the turbine, and then we only see flow increase when the hydro-power is at max capacity... so all of that river flow increase is not seen by the casual observer at the falls, but there has been no power generation for the time this thread has been alive, as the flow rate has been below 1% volume the whole time....
If HELCO is not generating power there, it is a very low flow rate...not "normal" - as an electric company would never have stated up if it was normal to NOT have electricity from their generation source, and Hawaiian Electric Light Co (HELCO) started with the Puueo hydro-generator....
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quote:
Originally posted by Carey
The flow has been at 13 CFS for the last 2 readings, vs the median of 264 CFS -& 25th percentile at 40CFS, granted it is not at the low recorded of 6.5 CFS or '78, bit is way closer to the lowest flow than even the 25th percentile flow, so I'm gonna guess that the flow was not 'normal' on Thurs...
Some posters may not even know that the Wailuku at Rainbow Falls is partially diverted, as there is a Hydro penstock above the falls. During lower flow, water is diverted at 10% of flow rate to run the turbine, and then we only see flow increase when the hydro-power is at max capacity... so all of that river flow increase is not seen by the casual observer at the falls, but there has been no power generation for the time this thread has been alive, as the flow rate has been below 1% volume the whole time....
If HELCO is not generating power there, it is a very low flow rate...not "normal" - as an electric company would never have stated up if it was normal to NOT have electricity from their generation source, and Hawaiian Electric Light Co (HELCO) started with the Puueo hydro-generator....
Carey, your way of explaining all the research you have done and what is going on is greatly appreciated. Thank you for all the work you are doing and for sharing it here on punaweb.[  ]
hawaiideborah
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quote:
Originally posted by pahoated
Even when some folks were complaining about the rain several months ago, others that have been here since the late 80's were saying it was still less than normal. If there is a prolonged dry spell, or less rain becomes more normal, this seems like it would start affecting catchment systems first. How long does a catchment system last without any rain?
Depends on where you are located, makai or Makua.
Depends on size of your catchment.
Depends on how much rain you catch with your system.
We have 12,000 tank with full gutter feed from 2 hip roof structures. In 3 years this tank has never needed filling.
hawaiideborah
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quote:
Originally posted by hawaiideborah
quote:
Originally posted by pahoated
Even when some folks were complaining about the rain several months ago, others that have been here since the late 80's were saying it was still less than normal. If there is a prolonged dry spell, or less rain becomes more normal, this seems like it would start affecting catchment systems first. How long does a catchment system last without any rain?
Depends on where you are located, makai or Makua.
Depends on size of your catchment.
Depends on how much rain you catch with your system.
We have 12,000 tank with full gutter feed from 2 hip roof structures. In 3 years this tank has never needed filling.
Is there a meter of some sort on your tank that can tell you how full it is at any given time?
-Veritas odium parit”(Terence 195–159 BC))-"Truth begets hatred".
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A square foot of horizontal surface receives approximately
0.625 gallons of water with each inch of rainfall.
(6) Surfaces that slope, like your roof, catch less water
per square foot of surface area. So it is not the area of
roof surface that you need to measure, but the roof’s
“footprint,” the area of ground under it.
This is quoted from Trish's book from UH about rainwater harvesting. So an inch of rain on 2000 sq. ft. is 1250 gallons. We divert about half of our rainwater past the tank here in Leilani and for two of us have never had less than a half tank. Similar to PV you buy low-flow appliances to conserve what you get and the less annual rainfall you have the larger collection and storage you need.
Air in the top of the tank is much warmer than the water usually so run your hand up the side and you should be able to tell what the water level is.
Jay
Jay
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Another issue is the waiawi. As it spreads, it uses much more water than the native forest (or the abandoned cane fields), leaving less to run off or soak in.
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And the rain last night allowed the production to resume... but still way below capacity...and 'normal'
There are many issues that may/will be coming upon us in the next couple of decades. I have been studying some of the effects other tropical-subtropical windward-rainforest islands have had the last few decades...our extreme oceanic buffer has protected us from much of what others have had, but within the last four years, we are beginning to see similar conditions...these conditions could be a very abnormal periodic cycle changes, or could be the start of a baseline shift...decades - centuries from now, some may be able to look back with the all-knowing 20/20 hindsight... but for us trying to establish action plans....
All we have is the data that has been taken & the data we are getting at present & try to determine if this IS the 'new normal'....which is why any & all data that anyone may have is sooo valuable (even wacky ol' uncle down the street who says he has written down his rain gauge info for the last 70 years... this is the type of data that some may pass off, but we are trying to get)...so those who have posted stating this is normal, if you have the data, really, not kidding... would love to have it!
How much this will effect our really big catchment, the windward aquifers, has yet to be seen.... but that is what I have been trying to tease, with all of the 'extras' this watershed has....
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I think there is more to it than that. Look at what's happening on the mainland. Super Warm. The weather is goofy all over the world. The jet stream is weakening and weather is just strange. I think the entire planet is heading into unknowns. You can't say what happened last year is the new norm for anything. Sadly I think man is having a huge impact on the weather system. Until then it's ganna be a bumpy ride.
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