After working for a couple of weeks, a crew of men (no women) have now sucked all the mud off the bottom of Botany Pond, exposing the cement that’s to be inspected for cracks. They’ve also exposed something I didn’t know about: there are barriers of cement in both the pond and channel, but they were so deep under the muck (there must have been three or four feet of mud) that I never detected them. Nor do I know what they’re for.
Plans call for inspection of cement, filling of cracks, and, I hope, regrading the cement so that there are at least two sloping areas where ducklings can exit the pond. Facilities doesn’t seem keen on making any provisions at all for the ducks next year, but we have an advisory biology committee now, consisting of four members, who will recommend amenities for the ducks. The next step after cement repair is re-filling the pond with soil.
Then, next Spring and Summer, the pond will be landscaped, and if all goes well, will be filled with water in October—just in time for migrating ducks to stop by. They also need to add microfauna to the pond: snails, aquatic animals like worms, and so on, for without those the pond will be sterile, supporting neither fish, turtles, nor ducks.
Here’s the channel: it’s much deeper than I imagined—almost as tall as I am. I never touched bottom or even detected the barriers when I was in there rescuing ducklings. I’m not sure if the pipes are new. Notice the two cement barriers. What are they for? The pond drain is to the right, at the end of the channel.
A panoramic view of the work. It’s below freezing today, and I feel sorry for the workers. I hope they get paid well! (It’s Saturday; they work six days a week.) The channel is in the foreground, the main pond in the background. Erman, on whose ledges many ducks have bred, is the building to the left.
We will have a duckless season next Spring and Summer, which is sad, as I may not get to see Honey at all.
Often those kinds of barriers are sediment traps. Water movement is slowed by a barrier, sediment comes out of suspension and is deposited in the trap, and sediment-free water passes on to the next section downstream. In theory—but this does not always happen regularly—one can dredge or shovel sediment caught in the traps and keep the entire system relatively clear of sediment. If the traps are not cleaned regularly the barriers are breached and the entire bottom gets covered in muck—as is apparently the case here.
I’m not saying that the barriers are for trapping sediment in this particular case, just that this kind of thing is done frequently.
“I’m not saying that the barriers are for trapping sediment in this particular case, just that this kind of thing is done frequently.”
Maybe my fantasy is a bit stunted, but what else could they possibly be for?
Providing shallow-water bases for planting various types of plants which would normally exist in parts of ponds five times the size? I remember doing something similar on a nature reserve pond … in the late 70s. But that was with battens of wood, piles and then heaping ballast and soil into the raised areas we’d built.
I enjoy behind the scenes!
I’m pretty disappointed in the university for not doing the work in time for spring for the ducks. It’s hard to believe they couldn’t do it in that time period if they hadn’t the right priorities.
It’s an oft-rehashed argument, but we did most maintenance work on “our” nature reserves in the winter because then, most of the plants were more-or-less torpid (and less sensitive to disruption), and most of the animals had either migrated away, or were hiding from the weather. And the “Conservation Corps” workers. Fewer detrimental effects over-all with winter work. About the only work we did over the summer was emergency repairs, bringing down hung-up wind-blown trees threatening paths (and the people who used them), re-hanging gates after the off-roaders had smashed up a bridleway, that sort of thing.
PCC(E) writes about the ducks. But the ducks may not be the primary reason for the pond’s existence. The name “Botany Pond” suggests that the Zoology department were not in the driving seat on this one.
Indeed, the ducks might be positively harmful to the lesser-spotted stinking sludgewort (other things that are green and squishy are available ; name is suggestive only) that the pond was established for. You’d have to find out who “established” the pond, and quite possibly left a bequest to fund it’s maintenance. That’s a far from rare situation in urban “green spaces”.
Oh, I did not understand – no pond, no ducks. That’s unexpected.
A year seems very longto finish this…
Four foot of muck, water saturated. So that’s upwards of a tonne of muck per square metre of pond to clear. And unless you (they) can get power tools (“back hoes”, whatever they’re called in the States) to the site, that’s work to be done by mitochondria and lumbar sprains in upright apes.
At least they’ve got people working 6 days a week on it, for money. Not one day a week volunteers, who you’ve (the works manager) still got a duty of care to.
What’s the area of the pond? From Google maps, I ball-park it at 150sq.m of pond (N 41.79079, E -87.59937), so upwards of 100 tonnes of muck to move upwards by over a metre.
This is one of those landscaping jobs where Dr Nobel’s Linctus for Excessively Tight Cave wouldn’t really help. Be fun trying though.
I suspect an ancient indigenous temple which will be claimed as sacred by the local Kenewick Nation. Confusion and a twitt*r war will ensue. None of us now living will survive to see the final resolution (if any).
Like you, Jerry, I am surprised at how deep it is. I always thought there was like eight or ten inches of water in the Botany Pond.
That’s very much the impression I’d got from Jerry’s duck pix too. So … why was it built so deep. Then edged and lined.
That deep a basin suggests that it was not designed to be a duck pond, but to support some other littoral species. The ducks are a side effect – and not necessarily a desired one.
Thanks for the update pics. Boy it really is deep!
Damn, now that’s a ton of work and 6-days a week to boot. Looks like a lot of progress has been made. No more wading, it seems. Duckling rescues might be impossible if the water is 6′ deep. Yikes. Turtles will love it.
Yes. I don’t see how that can happen with the current protocol of wading in.
I may have mis-read. I thumb-nailed it at upwards of a hundred tonnes, but on the basis of about a metre depth of muck. If it’s two metres, then well on the upside of 200 tonnes.
Big job.
I would suggest the walls are supports, like ribs on a ship, as perhaps the sides of the pond are not really strong enough considering the depth.
I agree with this assessment. Supports.
I think in winter the turtles would hibernate in the bottom mud or banks. Did they pull them out before dredging?
A while back Jerry posted that the turtles were removed before the renovation. 11 or 12 iirc.
They did some trapping, and uncovered at least one in the sediment when removing it. It is unclear how complete the catch was.
GCM
It seems like unnecessary bureaucratic slowness. I bet Olmstead could have managed it in a couple of weeks.
I agree with others here that the “ribs” are sediment barriers.
It doesn’t appear to be amphibian friendly either.
Due to the 3rd La Niña in a row, we have late rains this year. I have a very small, but amphibian friendly pond in my garden. Judging from the nightly clicking concerts they love it
Note, I dug the pond during the Great Drought in 2008: I heard no more soothing clicking, so I dug frog friendly pond. Still, in La Niña years the concerts are way larger.
“Due to the 3rd La Niña in a row, we have late rains this year.”
OHHHHHH, that makes sense!
Yes, it actually does make sense, although admittedly I didn’t formulate correctly (thanks for that) : there are always late rains (late spring, early summer) in the western part of South Africa during La Niña years. There is much more precipitation than during normal years, let alone El Niño years. Three La Niña years in a row is exceptional, and allows for amphibians to build large populations.
I hope it makes more sense now?
“admittedly I didn’t formulate correctly.”
Ha, yes I noticed that! But the idea of La Niña…
Hey, we are typing out in tiny windows what is ordinarily spoken in a conversation – it requires a correction to be calculated.
…. Aaaaand yes, now that I found a moment to pay attention – very interesting!
Suspect they’re waiting for at least a spring thaw before pouring any concrete.
Team Duck® is a lobbying group not to be ignored!