I look after a five-acre pond that’s thirty miles north of NYC. There’s not much to it. I keep the sluice clean, maintain the concrete and earth dam, and once every year or so I struggle to get a permit for a few irradiated (sterilized) carp to keep the weeds down (see note below). I’ve been doing this for twenty-five years.
In dry years the water level has fallen below the sluice a few times, but this has only happened in late summer. So far, 2012 is setting up as an extremely dry year. The overflow of this pond is down to a trickle. The water level will fall below the sluice in a matter of days.
The dry conditions extend past my little pond to most of the East coast. These slides from NOAA show the rainfall over the past 90 and 30 days. Many areas of the country have had 25% (or less) of average rainfall.
It’s not just the USA that is looking at a drought. The UK is dry as a bone:
A contributing factor to the change in rainfall pattern over the past three-months is that the two year long La Nina cycle is ending. ENSO neutral conditions in the Pacific Ocean have been re-established. From the April 16 report from NOAA:
The timing of the sharp reversal of water temperatures in two of the regions of the Pacific where the transition is taking place match the onset of the dry conditions:
The computer models forecast a shift from ENSO neutral conditions to a full El Nino over the next six months:
The record spring heat, the explosion of tornadoes and the below average rainfall have prompted a variety of reports blaming climate change for these occurrences. Maybe, maybe not. If the observable weather patterns are attributable to the change from La Nina to El Nino conditions, then there would be nothing unusual about it at all.
Look at how the Pacific Ocean has flip flopped from La to El conditions over the years:
My pond is designated as a class B watershed area for NYC’s water supply. As a result, there are many restrictions. (Basically it must stay as it is). No chemicals are permitted, so algae are an issue. Carp eat the green stuff, but if they multiply, they can devour all the vegetation. This would starve the water for oxygen. Hence the need for a permit to get the carp, and the requirement that the fish must be sterilized.
In mid-April the average overflow into the reservoir system is 2m gallons per day (I keep track), enough for 10,000+ people. As of today, that is down to zero. If the dry spell is extended much longer, water restrictions will be imposed on a wide section of the country.
To those NYers who do get some water from this pond, I’m doing my best to keep it clean for you. As far as I can tell, the whole system is pretty good.
There was one time that two deer fell through the ice and drowned. They bloated up and floated for a month. Stank like hell before they sank. That’s part of the mix too…