dew ponds

[egbert]

Anyone on here understand their workings?
Not something we traditionally had to look at with 90" of rainfall, and water oozing everywhere.
But seen them on chalk ground to the East.

How do they fill?
Is it the cooling air sliding over the brow of an evening, dropping into the pond sited to catch it?
(like the sweet smell of hay that fills the yard evenings hay time)
Was/is there folk who know how to set em up?
They've been around for thousands of years after all.

 

[suffolksmallholder]

Up close to the Chilterns escarpment there were many dew ponds. Some if not all filled from seepage through the clay and the thin layers of flint that were ever present.
Lie-of-the-land was also important in that rain water pooled on specific places and people took advantage of this. Increase the capacity of a dip and you’ll have water for a couple more months in summer time.
The very best were marked with a W on the drovers routes. Some were even turned into 10,000 gallon tanks.

All the dew ponds I know have what looks like a little bomb hole. Only 8’ round and sometimes a similar depth from the surrounding ground. This fills with water over several days and in winter time the water area increases to 60’.
I know of one dew pond that was turned into a small reservoir and there was a channel dug to a smaller indent. This was filled by rotating a 12’ wheel on which were attached pint pots. The water could sustain 12 head of coos over a dry summer over 20 acres of grassland.
SS

 

[mixedfmr]

lots of these on the york wolds, we had one to share for every 2 fields, man made and would have been filled with winter rain, but they have not been maintained for a long while and now leak, or have been filled in, Not many animals left there now

 

[neilo]

Perfect fluke habitat, long gone on most places round here, either fenced off (Glastir) or filled in.

 

[Tim W]

There's one I know of on chalk downland that was working 20 years ago, ...we dug a small indent in the bottom of the pond & put a plastic bowl in, it would fill about a hands depth on a good summer morning.

 

[egbert]

Perfect fluke habitat, long gone on most places round here, either fenced off (Glastir) or filled in.

classically, they'd be sited in dry country where there wouldn't be much fluke- and no natural water for stock. Not aware that fluke was an issue.

I've been thinking about them since encountering them on South Downs backalong, with a farmer who explained many still function perfectly well.
Then on an iron age fort in Dorset, where the kind farmer in residence explained that when the marauding barbarians (or whoever) arrived, locals would flee up onto fort with what stock they could.
When asked how they had enough water, he explained that as we'd driven up past the outer rings, there was a little dew pond dug in the slope, which was enough.

Google doesn't have much answer how they work, despite several attempts to quantify the biz.
There's lots about how they were best constructed etc.
They are oft sited where no springs rise, and many seem to have had water reliably in them despite no rainfall......but how?

My own obs are that they're sited just off the hill top.
And as alluded, as summer evenings cool here, (when we're harvesting and the weather is kind) the smell of hay making in the inbye up the slope engulfs the yard.
Then, after a party on a 1300' farmyard a few years ago, my beloved and I made our way home late in the evening, and watched the fog pouring down the slope above in the moonlight.
Does damp air slide down the slope in the cooling evening hours, and the shape and siting of the dew ponds encourage condensation/deposition in and around the pond????????

come on forum...someone knows.

 

[Homesy]

Capturing the Clouds: The History of Britain's Ancient Dew Ponds - RuralHistoria

Dew ponds, those mysterious man-made features of the rural English landscape, have a fascinating history that spans centuries.

ruralhistoria.com

 

[HatsOff]

Google AI suggests the following

Dew ponds are artificial ponds, often located in dry areas, that primarily rely on rainfall for their water supply. Despite their name, dew doesn't contribute significantly to their water levels.

Here's how they work:

Construction: Dew ponds are typically shallow and have a saucer-shaped design. They are lined with waterproof materials like clay or plastic to prevent water from seeping into the ground.
Water Collection: The primary source of water is rainfall. When it rains, the water collects in the pond, thanks to the waterproof lining.
Water Retention: The saucer-shaped design helps to minimize evaporation, ensuring the water stays in the pond.
Additional Sources: While rainfall is the main source, dew, fog, and melted snow can also contribute to the water level, especially in cold, humid conditions.
Key points to remember:

Dew ponds are primarily dependent on rainfall.
The waterproof lining prevents water loss.
The saucer-shaped design helps retain water.
Dew ponds have been a valuable resource in areas where natural water sources are scarce, providing water for livestock and other needs.


Sources and related content
Dew ponds - Brighton & Hove City Council

www.brighton-hove.gov.uk

Dew pond - Wikipedia

en.wikipedia.org

Restoring and managing dew ponds | Yorkshire Wildlife Trust

www.ywt.org.uk

Creating a Dew Pond - Butser Ancient Farm

www.butserancientfarm.co.uk

Make your own mini dew pond - Yorkshire Wildlife Trust

www.ywt.org.uk





Gemini may display inaccurate info, including about people, so double-check its responses.

Not sure I see the significance of the bowl with regards to evaporation so think that could be an AI hallucination.

On Ascension Island there is a true dew pond (now long disused) and a lot of tropical and temperature plants were planted at the top of the volcano to encourage the dew to form and condense.

 

[egbert]

Capturing the Clouds: The History of Britain's Ancient Dew Ponds - RuralHistoria

Dew ponds, those mysterious man-made features of the rural English landscape, have a fascinating history that spans centuries.

ruralhistoria.com

A good piece, albeit that it never identifies the bottom line....how they fill.

The term “dew pond” itself is somewhat of a misnomer, as it suggests that these ponds were filled solely by the condensation of dew, whereas, in reality, they also collect rainwater and runoff. ......is the giveaway.
I don't think it's the dew just over the pond. It's collecting moisture from the evening 'runoff', as it passes- and the author goes on to quote examples where it clearly ISN'T runoff /rainwater.

Google AI suggests the following



Not sure I see the significance of the bowl with regards to evaporation so think that could be an AI hallucination.

On Ascension Island there is a true dew pond (now long disused) and a lot of tropical and temperature plants were planted at the top of the volcano to encourage the dew to form and condense.

The 'roundness' seems to be common.
Annoyingly, a lot of the photos in that link are looking down hill...it is the slope above that's as important.

 

[NEmesis]

I suspect Richard Jeffries, Gilbert White or AG Street will most likely have an explanation. I always understood them as shallow hollows lined with clay on the chalk downs collecting overnight condensation and rain precipitation. Grazing sheep in our climate have little demand for drinking water so I guess all the time the dewpond had water in them available the shepherd is content.
Really a meteorologist or geologist /geographer question.

 

[mixedfmr]

classically, they'd be sited in dry country where there wouldn't be much fluke- and no natural water for stock. Not aware that fluke was an issue.

I've been thinking about them since encountering them on South Downs backalong, with a farmer who explained many still function perfectly well.
Then on an iron age fort in Dorset, where the kind farmer in residence explained that when the marauding barbarians (or whoever) arrived, locals would flee up onto fort with what stock they could.
When asked how they had enough water, he explained that as we'd driven up past the outer rings, there was a little dew pond dug in the slope, which was enough.

Google doesn't have much answer how they work, despite several attempts to quantify the biz.
There's lots about how they were best constructed etc.
They are oft sited where no springs rise, and many seem to have had water reliably in them despite no rainfall......but how?

My own obs are that they're sited just off the hill top.
And as alluded, as summer evenings cool here, (when we're harvesting and the weather is kind) the smell of hay making in the inbye up the slope engulfs the yard.
Then, after a party on a 1300' farmyard a few years ago, my beloved and I made our way home late in the evening, and watched the fog pouring down the slope above in the moonlight.
Does damp air slide down the slope in the cooling evening hours, and the shape and siting of the dew ponds encourage condensation/deposition in and around the pond????????

come on forum...someone knows.

Each of the dew ponds that i knew where at the lowest point for their accessability to their shared fields, in corners. So possibly some truth in the mist theory
It takes me back, never really thought about them as a boy, just a waste of land as we cultivated every inch then

 

[suffolksmallholder]

I resurrected a few dry and silt filled ones.
Once you have removed the mud/silt/rubbish which, more often than not contained the iron band of a wagon wheel and my best ever find; a piece of ‘forward horse’ harness, you can then get near the bottom.
I only re dug them in very dry times.
Once at the bottom the job was finished although some minor alterations were required such as creating a step to stop weed encroachment.
This may well have been done in the original scrape and wrecked by hoofs over the years.
By day three there was always a foot of water in the bottom!
Another thing, they were dug in the opposite way to the slope and often had a small near vertical bank into the slope tied with tree roots.
SS

 

[HatsOff]

A good piece, albeit that it never identifies the bottom line....how they fill.

The term “dew pond” itself is somewhat of a misnomer, as it suggests that these ponds were filled solely by the condensation of dew, whereas, in reality, they also collect rainwater and runoff. ......is the giveaway.
I don't think it's the dew just over the pond. It's collecting moisture from the evening 'runoff', as it passes- and the author goes on to quote examples where it clearly ISN'T runoff /rainwater.

The 'roundness' seems to be common.
Annoyingly, a lot of the photos in that link are looking down hill...it is the slope above that's as important.

I suppose it forces all the water to collect in one location which helps with slowing evaporation. And that is more important for small quantities of water. (I was thinking a full bowl Vs a full cube where there wouldn't be much difference in evaporation).

 

[suffolksmallholder]

The pond that resided in the parkland and had the wheel with pint pot dippers on it had some tremendous earthworks surrounding it, not big in scale, just in length as they formed a catchment area hundreds of yards long to direct rainwater along the lands gentle slope. These were to direct the rainwater in the right direction.
They are still there today and still show very clearly in snow making one think ‘why is this here?’ Then ones mind starts working and remembering stories told by the generation who were young before 1914.
SS

 

[egbert]

I'm starting to see them as 'sediment traps' ....for moisture laden air.

The pond that resided in the parkland and had the wheel with pint pot dippers on it had some tremendous earthworks surrounding it, not big in scale, just in length as they formed a catchment area hundreds of yards long to direct rainwater along the lands gentle slope. These were to direct the rainwater in the right direction.
They are still there today and still show very clearly in snow making one think ‘why is this here?’ Then ones mind starts working and remembering stories told by the generation who were young before 1914.
SS

Were the earthworks directing surface water, or tall enough to deflect air into the 'funnel' ?
I'm going to see if I can talk to my pal in dorset with the hillfort.
(I feel an 800 worder coming on)

 

[Yale]

The ethereal art of fog-catching

In chronically dry regions around the world, communities are finding ways to live from the water suspended in the air – creating valuable drinking water from mist.

www.bbc.com

Off topic but.

After watching the video is the grass that populates a dew pond as important as the structure itself. It seems the magictrickery could be related to thin grass leaves acting as the moisture capture mechanism.

 

[Derrick Hughes]

Was a few of them on my farm in Wales , before we had mains water

 

[suffolksmallholder]

I'm starting to see them as 'sediment traps' ....for moisture laden air.

Were the earthworks directing surface water, or tall enough to deflect air into the 'funnel' ?
I'm going to see if I can talk to my pal in dorset with the hillfort.
(I feel an 800 worder coming on)

Directing surface water. They weren’t deep.
I did the same when creating a homestead in Tas.
SS

 

[JCB_JCR]

Looking at old maps there was a pond in most field corners here with several around, or near, the farm yard. The motorway took out a few and dropped the water table. Some are still here but are over grown and dry up fairly quickly in a dry spell.

 

[Exfarmer]

Dew ponds would very rarely harvest sufficient water from the overnight dew to counter the evaporation during the day. Most summers days this would average up to 2-3mm sometimes on a hot day 4mm.
Dew ponds have been located most places but are most succesful on the north side of a hill where the direct rain will be supplemented water flowing down from above both over and under ground.
They were made by digging the hole then laying straw in the bottom and penning sheep in the hole this will puddle the bottom. Frequsantly they will benefit by tapping sub surface strata just as you often find quite shallow ewells which produce prodigious quantities of water. In Buckinghamshire we had 2 such wells no more than 8 feet deep on the side of hills which fed a 150 cow milking herd and followers