Valley Creek cfs anomolous spikes

[lestrout]

For the past several days, there's been a lot of concern over strange spikes of water flow from 15 to 30 cfs, according to the USGS gauge at the Turnpike. At first VFTU feared that a water main break was underway. The last fishkill was 3 years ago, almost exactly, but AQUA has been making steady progress ungrading the antiquated water supply infrastructure. We checked with the National Park and Treddyffin Township Engineer to find no reports of any breaks. The VFTU monitoring stations above and below the Knickerbocker Landfill project at Ecology and Valley Creek Parks show no unusual activity, so whatever's happening is between Rte 29 and the USGS gauge.

Several of the chloride metrics show unusual spikes, and this week has been unusually frigid, with USGS showing water temperatures right at 32 degrees, which is freezing. I can't recall ever seeing it that low, being that Valley is spring feed and has considerable bottom release inflow from the quarry.. The contractors and DOT has put down a lot of salt with the snow we've had, but it's been so frigid that the usual slushy daytime meltoff hasn't happened. Turbidity is fine - unusually a water main break clouds up the stream considerably.

In any case, if anyone is on the water and sees anything unusual, particularly dead fish, please let us know.

https://waterdata.usgs.gov/nwis/uv?site_no=01473169&legacy=1

 

[Swattie87]

Any chance it’s just ice affecting the gauge? A lot of the USGS gauges are showing screwy readings due to ice currently. Look at the link on the site and all the white on the map, indicating the gauge isn’t reading normally. From just eyeballing it, I’d say 2/3 or more of the gauges in the state are currently having issues.

I know Valley has a strong limestone influence, and it would be more difficult for it to freeze than a freestoner, but perhaps the gauge is in a location (slack water area) that may freeze more easily. Totally speculation, as I’m not terribly familiar with Valley’s gauge. I recall where it generally is, but don’t remember the details of the water it’s around.

Edit: Just took a look at Valley’s gauge, and the spikes coincide with the gauge indicating a temperature of 32F. There weren’t any prior when it was reading above freezing, even if just by a little bit. I’d say ice buildup overnight with some mild thawing during the day affecting the gauge is the most likely culprit. In the absence of any evidence to support the other things you mentioned Les.