How much rain will cure hosepipe issues/canal depth/reservoir levels?

[ghostlymoron]

I read today that the drought is expected to last till Christmas. Why should it be reckoned to end then?

I wonder how needy we'll have to be for water, before theoretical, 'proposed' new reservoirs become urgent projects? I imagine compulsory purchase of land in valleys required for reservoirs, would be made in days, if we suddenly couldn't water crops.

It's crazy if we invariably wait till it's desperate (and possibly too late) before the wheels seriously start turning.

How does that pricey pipeline-from-the-Highlands compare cost-wise, with Western Australia's desalination plants, or horrendously costly pipe-repairs, or half a dozen new thousand-acre reservoirs, which'd need years to fill, anyway?

Presumably having a reservoir, full or empty, would allow it to be filled, if we had the pipeline from rainier parts.

If we're sustaining our use of water mainly from underground supplies while they're not consistently replenished...

...aren't we edging blindly and conceitedly towards a ghastly dustbowl crisis, with widespread economic fallout?

I can't help thinking we shouldn't only have hosepipe bans - we ought to limit all freshwater use, the way we do aboard yachts!

Yes all good points but you have to remember that simply building a reservoir does not increase the water supply - you have to have the rain to fill it.
Pipeline from the highlands is not the way to go. Interlinking existing waterways - river or canal - with short pumped sections between catchments is the economic way to do it.
If everybody lived in a boat for a time (or a caravan) they would soon learn to use water wisely. I've had non-boating friends aboard who have had to be chastised for leaving the tap running while they were cleaning their teeth!
I haven't done the calcs on desal v water grid but, having installed several reverse osmosis plants, am aware of the huge pumps required for desal.
As for washing cars - I wash mine once a year prior to waxing it (come to think of it, I think I forgot last year) doesn't look any different though.

 

[lw395]

Unfortunately you can only start from where you are. Water shortage has not been a problem in the UK until recently (except 1976) thanks to the overdesign by earlier Victorian engineers and there would have been little appetite for investment in extra storage facilities. With the exception of Carsington and Kielder.
Desalination is a last resort IMHO because of the high power requirement of reverse osmosis. We should be looking at distributing the resources from North to South for existing population and discouraging further development in the dry parts of the country. If you can't provide water, you shouldn't build more houses/factories.
Bosses bonuses are a curse of all industries but are insignificant compared with the million pounds per mile cost of new water main.

I think bigger desalination is sometimes done by vacuum distillation, which can be more efficient? The price per tonne can be in the same league as current costs IIRC, particularly if the waste heat from a power station is used.
The capital costs and energy requirements of a water grid are immense.
Try calculating the pipe losses for a 100mile long pipe for various flow rates and pipe sizes...

 

[ghostlymoron]

I think bigger desalination is sometimes done by vacuum distillation, which can be more efficient? The price per tonne can be in the same league as current costs IIRC, particularly if the waste heat from a power station is used.
The capital costs and energy requirements of a water grid are immense.
Try calculating the pipe losses for a 100mile long pipe for various flow rates and pipe sizes...

Don't know about vacuum distillation so can't comment.
Agree that friction losses in long pipelines are huge, that is why it would be necessary to keep pumped sections short and use existing waterways/canals for the bulk of the transfer.

 

[lw395]

Don't know about vacuum distillation so can't comment.
Agree that friction losses in long pipelines are huge, that is why it would be necessary to keep pumped sections short and use existing waterways/canals for the bulk of the transfer.

This is Daily Mail stuff.
The existing canals are small and not designed for flowing water. They are level, as you would expect with still water, but any significant rate of flow would have them empty at one end and overflowing the banks at the other. They would also need to be rebuilt to prevent erosion. The whole thing is a shallow 'solution' that does not survive even a basic analysis.

 

[ghostlymoron]

There are many canals in the UK that are already used for water distribution.

 

[Greenheart]

We need to be better prepared, dam it!

I hadn't thought of it hard enough, but I reckon lw395 is probably correct. What we'd need would be more like LA's storm drains...

...à la Terminator 2. Not exactly scenic, or cheap to install.

I read that the nuclear power station at Sellafield takes, or took, up to 18,000 tonnes of water per day from the lake, Wastwater...

...that's a cube, with 87' sides, or about 1/4" off the lake's surface! I wonder how that quantity arrived at the plant in 24 hours?

Assuming we're currently enduring a temporary dry period, and that rain will eventually return to its traditional bank-holiday-ruining weight and regularity, isn't now the time to dam expendable lowland valleys, to be ready for next time we run dry?

 

[aquaplane]

I don't suppose anyone would consider moving the jobs and people to where the water is?

 

[Deleted member 36384]

...... to dam expendable lowland valleys, to be ready for next time we run dry?

The geological conditions for reservoir building are not that common and most have been exploited in Britain. A lot of rock and soil types are not water proof and valley floors can have poor load bearing capacity. To overcome these issues requires significant engineering work and capital outlay.

 

[Kurrawong_Kid]

The geological conditions for reservoir building are not that common and most have been exploited in Britain. A lot of rock and soil types are not water proof and valley floors can have poor load bearing capacity. To overcome these issues requires significant engineering work and capital outlay.

A North of Scotland Hydro Electric Board employee once told me that there would be no more HEP reservoir schemes built because the price of land was now so expensive that they could never again be viable. Presumably the same argument applies to water reservoirs. In my view these lands should be commandeered for national usage without capital compensation to the owners; but that they should be paid an annual income as interest on their "loan" of the land in the national interest at say, .05%!

 

[Twister_Ken]

I read today that the drought is expected to last till Christmas. Why should it be reckoned to end then?

Certain things will always 'all be over by Christmas'. Especially wars.

 

[lw395]

There are many canals in the UK that are already used for water distribution.

Very true.
In a limited way, as opposed to being a solution to having a million or more extra houses in the south that the system struggles to provide for, and people expecting water to be very, very cheap, if not unmetered.

 

[Twister_Ken]

As an ex water company engineer, it infuriates me when ill-informed statements such as this are made. Water companies have already spent millions on leak finding and repairing. The majority of remaining leaks are below ground and not visible from the surface.

Far be it from me, etc, etc...

I reported a leak on Feb 14 (I remember the date coz I was walking home from taking Madame for a Valentine's supper). Water bubbling through the pavement and running away down the gutter. Difficult to estimate the flow rate, but roughly the equivalent to several garden hoses going at full chat. Thames Water thanked me profusely, and didn't turn up to make the repair until a MONTH later! By that time, the water had frozen overnight several time, seriously damaged the road surface, put a pelican crossing's electric's out of action and made the pavement out of bounds to pedestrians because of the risk of getting a soaking from traffic passing through the puddles. How many olympic sized swimming pools I wonder?

Not much incentive to repair that leak then!

 

[Greenheart]

That is appalling, Ken. A definite smell of rank incompetence or inadequacy, about your local water company.

The geological conditions for reservoir building are not that common and most have been exploited in Britain.

Is that right? I was supposing that traditional rainfall in times gone by, made reservoirs look like a wasteful use of valuable land...and that only now, when we're so dusty dry, do we wish we had more ponds.

Has over-use of aquifers so dessicated the land, that water no longer pools on the surface as lakes, but soaks away instead?

Either way, wouldn't it benefit the land, if river-water was dammed up, upstream, soaking away, rather than gushing out to sea?

Mightn't there be something to be said for raising/expanding the embankments/dams, if necessary around the entire shoreline of reservoirs, for the extra content each lake could thereby contain? Inland sailing clubs would thrive...

I know that's not much help when existing reservoirs are so far below their maximum content - I'm just trying to think ahead!

 

[maby]

Is that right? I was supposing that traditional rainfall in times gone by, made reservoirs look like a wasteful use of valuable land...and that only now, when we're so dusty dry, do we wish we had more ponds.

Has over-use of aquifers so dessicated the land, that water no longer pools on the surface as lakes, but soaks away instead?

.....

I think water only ever pooled on the surface as lakes in places where the geology was right.

 

[lw395]

That is appalling, Ken. A definite smell of rank incompetence or inadequacy, about your local water company.



Is that right? I was supposing that traditional rainfall in times gone by, made reservoirs look like a wasteful use of valuable land...and that only now, when we're so dusty dry, do we wish we had more ponds.

Has over-use of aquifers so dessicated the land, that water no longer pools on the surface as lakes, but soaks away instead?

Either way, wouldn't it benefit the land, if river-water was dammed up, upstream, soaking away, rather than gushing out to sea?

Mightn't there be something to be said for raising/expanding the embankments/dams, if necessary around the entire shoreline of reservoirs, for the extra content each lake could thereby contain? Inland sailing clubs would thrive...

I know that's not much help when existing reservoirs are so far below their maximum content - I'm just trying to think ahead!

AFAIK the problem is more a lack of water to pump into reservoirs, than a lack of reservoir space to store it in. A lot of rivers in the south east barely flow into the sea anymore, the water is all pumped away, to the limit of what is allowed.

 

[Greenheart]

...the problem is more a lack of water to pump into reservoirs, than a lack of reservoir space to store it in. A lot of rivers in the south east barely flow into the sea anymore, the water is all pumped away, to the limit of what is allowed.

Here's a crazy thought, then...

...feel free to point out the flaws that I haven't thought of yet, it being less than a minute since it came to me...

If a very tidal river like the Arun, was dammed at its mouth, down in Littlehampton...surely the substantial lower course of the river, which currently floods with brine every high tide, could be permanently filled with fresh water, without inundating any new land?

Quite an engineering job, doubtless, but no more than has been achieved before, surely? The fact that the Arun's mouth is no more than 50m wide, might make it a good deal easier (faster, anyway) to build.

The flat land around Chichester/Bognor is largely agricultural...and must need a good deal of watering in drought periods. The river-water wouldn't need a lot of lifting, from the present high-water mark, to reach crop-spots.

Isn't current policy, to make excuses, while every hour, thousand of tonnes of usable fresh river water pours into the sea?

Umm...I just remembered this is a boating forum. Well, couldn't the dam incorporate a lock, for access? Like many marinas?

 

[WilliamUK]

If a very tidal river like the Arun, was dammed at its mouth, down in Littlehampton...surely the substantial lower course of the river, which currently floods with brine every high tide, could be permanently filled with fresh water, without inundating any new land?

Habitat destruction on a grand scale. There's far more to tidal estuaries than you seem to be considering.


EDIT
Oh, and I wouldn't be so sure I'd call river water "usable, fresh water". Consider how much agricultural land drains into most rivers outside the unfarmed national parks. Consider how much of it contains fertiliser and pesticide runoff (some of which is truly nasty stuff) and that standard water treatment isn't likely to remove it. Not that the current water supply is exactly amazing on that front, but I'd suggest that collecting water as far from source as possible is about the worst possible option when you consider health, quality and safety.

 

[Greenheart]

Habitat destruction on a grand scale. There's far more to tidal estuaries than you seem to be considering.

Even if the new, dammed fresh water level is no higher than high tides routinely were, previously?

Also...(and no-one likes wildlife at its undisturbed best, more than I)...mightn't that destruction be better than a Sussex dustbowl?

 

[maby]

Habitat destruction on a grand scale. There's far more to tidal estuaries than you seem to be considering.

I think it would also take a very long time before the water contained in such areas would be drinkable - it will be sitting on mud and sand that is well loaded with salt.

 

[WilliamUK]

Even if the new, dammed fresh water level is no higher than high tides routinely were, previously?

Also...(and no-one likes wildlife at its undisturbed best, more than I)...mightn't that destruction be better than a Sussex dustbowl?

Tidal rivers expose the shallows twice a day. Permanent flooding is permanent.

...and I'm inclined to think it'd be an appalling tradeoff. We could fix leaks, reduce usage, put in a parallel non-potable system, require all building works done henceforth to re-use grey water in toilet cisterns and so on... but because that's unpopular or expensive we should consider permanently flooding (with freshwater) important habitat that is tidal and saline? I disagree. That should be the absolute last resort to be considered only when everything else has been tried... including population relocation.