Watching Wetland Water Levels – Timelapse Photography

It’s timelapse photography time again…  I downloaded more photos from the cameras at our restored wetland in the Platte River Prairies a couple weeks ago, and have been looking through the images for stories.  One theme that stood out in this batch was the variability of the water level in the wetland through time.

This wetland is directly connected to the water table, but is also supplied by a groundwater-fed stream that brings both rainwater and groundwater from about 25 miles west of us.  Platte River flows and irrigation pumping both influence the water table here in the Platte Valley, as does evapotranspiration by plants – and other factors.  It’s a complicated series of events and processes.  However, in general, we expect the water table to be relatively high in the spring and to decline as summer progresses.  I looked at photos from early June and early July (below) and that pattern of summer decline is apparent this year.

June 8, 2014

June 8, 2014.  A panoramic image created by merging photos from two adjacent timelapse cameras.

July 8, 2014

July 8, 2014.  You can click on each photo to see a larger/sharper version of it.

Seeing the pattern of water level rise and fall through weeks and months is interesting, and timelapse photography allows us to watch that pattern pretty easily.  However, it’s also interesting to look at shorter-duration patterns.  I shared one example of that back in December, with a series of images showing daily water level drops due to evapotranspiration.  Today, I’m sharing a second example of short-term water level changes – this time, it’s due to water coming downstream after a rain event.

In the early morning of June 21, 2014, a big storm system moved through our area, dumping between 2 and 4 inches of rain.  The map below shows the precipitation amounts from that storm.

This photo from http://water.weather.gov/precip/ shows rain amounts for our area on June 21.  The black arrow indicates the location of our wetland.

This image from the National Weather Service (http://water.weather.gov/precip/) shows rain amounts for our area on June 21. The black arrow indicates the location of our wetland.

Rainwater from the storm swelled the stream that flows into our wetland, but also created runoff flow throughout the watershed.  The Youtube video below shows the water level changes in our wetland through the day on June 21, 2014, starting at 7am and ending at 8pm.  The changing light conditions from image to image make it a little difficult to see, so you may have watch it several times to get the full effect.  The foreground, the green peninsula on the left, and the little island just left of center are all good landmarks to help see the water level change.

There’s nothing earth-shattering about stream or wetland water levels rising and falling after a big rain event.  On the other hand, it’s not often we get the opportunity to actually see it happen.  Timelapse photography gives us the opportunity to compress time and see natural processes from a different perspective.  For me, at least, that opportunity helps me better understand and appreciate the variability of the earth we live on.

As always, thanks to Moonshell Media for their help with this timelapse photography project.  If you’re interested in exploring timelapse photography for conservation purposes, you can contact them at 402 817 4313 or info@moonshellmedia.com.

Photo of the Week – April 3, 2014

This week, I present four photographs from one of the timelapse cameras along a restored wetland in our Platte River Prairies.  All four photographs were taken automatically by the camera, and none are particularly striking images, artistically speaking.

Nice sales job, eh?

Despite their quality as images, or lack thereof, they are very meaningful photographs to me.  In fact, the two photos of least photographic quality are actually the two I like best because they tell a story I’ve been hoping for since we first started the wetland restoration project more than 10 years ago.

Canada geese, some wigeon, and a few other ducks sit on the restored wetland in March of this year.  This is a common sight, and a good one, but I was always hoping for more than just ducks and geese to use the wetland.

Canada geese, some wigeon, and a few other ducks sit on the restored wetland in March of this year. This is a common sight, and a good one, but I was always hoping for more than just ducks and geese to use the wetland.

When we first started talking about converting a long sand pit lake (left over after sand and gravel mining operations from early last century) into something different, we had several objectives.  Those included:

– removing the trees around the edge of the site to improve habitat for open-grassland and wetland wildlife species.

–  providing shallow stream and wetland habitat for fish, amphibians, reptiles, invertebrates (including mussels), and other species.

– restoring diverse plant communities including emergent wetland, wet meadow, wet-mesic, and upland sand prairie communities.

– providing habitat for migratory whooping and sandhill cranes and many other waterbird species with similar habitat requirements.

The first three objectives were pretty easy, and we’ve seen abundant evidence of success.  In terms of bird habitat, we’ve always had great utilization of the site by ducks, geese, herons, snipe and other birds during both migration and breeding season.  But no cranes.

Until this spring.

The chance that one of (approximately) 260 whooping cranes will ever land in this particular wetland is very remote, but I have been expecting to see sandhill cranes using the site; if not for overnight roosting habitat, at least as a place to feed and loaf during the day.  After all, there are hundreds of thousands of sandhill cranes here each spring – surely some of them should see this as an attractive place to hang out now and then.  And if we see sandhill cranes using the site, we can reasonably assume that it’s suitable for whooping cranes too (though that’s not universally true).

However, during the 10 years since we started the restoration work, I’ve been looking in vain for a crane of any sort, or even tracks that would indicate they’d been there.  Nothing.  Last year, we had timelapse cameras up during the spring crane migration season but they malfunctioned and didn’t give me any evidence one way or the other.  But this year, I finally got what I wanted.

Three sandhill cranes stand in the middle of the wetland on March 8 of this year.

Three sandhill cranes stand in the middle of the wetland on March 8 of this year.  You can click on the photo to see a larger version of it.

I downloaded images from the cameras in mid-March and immediately scanned through them in the truck, hoping to see some evidence of crane use and – there they were!  Three sandhill cranes showed up in multiple photos over the period of a couple weeks.  Most of the photos were daytime photos, but it also appears they roosted overnight at least a few times, standing in the shallow water.  Three cranes is certainly not evidence that we’ve added significantly to bird conservation, but it is evidence that our wetland isn’t completely abhorrent to cranes – and that’s a good start.

Then, as I kept looking through the images, I got an even better surprise. Late in the evening on March 11, there was a whole flock of cranes standing in the shallow wetland, apparently preparing to roost.  Even better, the camera picked them up again early the next morning – pretty solid evidence that they roosted overnight.  It only happened once (through mid-March) but I’ll take it!

A flock of 70-80 sandhill cranes stands in shallow water at 7pm on March 11.

A flock of 70-80 sandhill cranes stands in shallow water at 7pm on March 11.

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At 7am the next morning, the cranes are still there - maybe more of them, in fact.  Our first real crane roost, that we know of.

At 7am the next morning, the cranes are still there – maybe more of them, in fact. Our first real crane roost… that we know of.

The pictures aren’t of terrific quality.  They were taken by a camera set to fire every hour on the hour (during daylight hours) and low light and wind combined to the images a little blurry.  Nevertheless, I think they’re pretty great photos.

Of course, now that I’ve gotten my evidence of crane use, my scientist brain is kicking in and asking questions.  Why did the cranes only roost one night?  Why that particular night?  Why did they pick that particular part of the wetland?

And, there’s one more question my brain is asking, which I’m trying to ignore because I don’t think it’ll ever happen.

…Will we ever see a big white crane in one of those photos?