EBB AND FLOW

The CRT out­lines its strat­egy to deal with the chal­lenge of wa­ter short­ages

Canal Boat - - This Month -

IT seems rather per­verse to be writ­ing an ar­ti­cle about canals run­ning short of wa­ter when it’s the mid­dle of win­ter, the rain is lash­ing down out­side, and a stream of Canal & River Trust alerts are com­ing in, warn­ing of rivers all over the net­work go­ing into flood con­di­tions. But un­til a cou­ple of weeks ago there were se­ri­ous con­cerns about canal wa­ter stocks, not just for the im­me­di­ate fu­ture (with part of the Grand Union Le­ices­ter Sec­tion still in­def­i­nitely closed af­ter four months), but for the forth­com­ing year – and CRT was mak­ing con­tin­gency plans to make the most of what stocks it had.

Of course, Sod’s Law says that when­ever you plan an ar­ti­cle about wa­ter short­ages, by the time you’ve fin­ished writ­ing it there will be floods. And sure enough, as we go to press the Le­ices­ter stop­page looks set to come off, reser­voir lev­els al­most ev­ery­where are look­ing healthy, and it’s easy to start won­der­ing what all the fuss was about. But it’s not like the re­cent weather has been spec­tac­u­larly wet­ter than the au­tumn (un­like, say, the Box­ing Day 2015 floods that hit the North of Eng­land) - so what hap­pened?

CRT’s Head of Wa­ter Re­sources Adam Comer­ford ex­plains that it’s all about ground­wa­ter. As he de­scribes it, the ground is like a gi­ant sponge: a dry win­ter and spring last year left it very dry to start with; when the au­tumn rain­fall ar­rived, it tended to just soak into the ground and grad­u­ally fill up its ca­pac­ity, rather than run­ning off into the streams which feed the reser­voirs.

But fi­nally, right at the end of 2017, the ‘sponge’ filled up, it couldn’t hold any more wa­ter, and the rain­fall and melt­ing snow around Christ­mas and New Year went straight into the streams. In Adam’s words it was much more “ef­fec­tive” rain in terms of fill­ing up the reser­voirs. He quotes some fig­ures to show just how dra­matic a change it was.

Sadding­ton, the main reser­voir sup­ply­ing the north end of the Le­ices­ter Line, went up from a wor­ry­ingly low (for the time of year) 52 per­cent full to a healthy 87 per­cent in just one week – to put it in con­text, that’s some­thing like an ex­tra 600 lock­fuls, and there were sim­i­lar im­prove­ments at Welford and Sulby reser­voirs.

That’s just one of sev­eral ar­eas which had given cause for con­cern. The other re­stric­tion (due in part to pump prob­lems as well as lack of wa­ter) was the Grand Union’s Tring Sum­mit. Here, to com­pli­cate mat­ters slightly fur­ther, the Mar­sworth reser­voirs are largely fed di­rectly by ground­wa­ter (think of it as wa­ter ooz­ing out of the sat­u­rated ‘sponge’) so it’s less pre­dictable when they will start to fill up. But here, too, the sit­u­a­tion is sud­denly look­ing a lot bet­ter – and for the longer term, CRT is look­ing to im­prove pump re­li­a­bil­ity.

The other main area of con­cern is the Birm­ing­ham Canal Nav­i­ga­tions and con­nected canals. This tra­di­tion­ally is well-sup­plied with wa­ter, but has been hit by a com­bi­na­tion of cir­cum­stances: • Up­per Bit­tell Reser­voir lev­els were

drawn down for safety work • Rot­ton Park hadn’t re­filled well dur­ing 2016-17 and was run­ning very low • At Earlswood there was work to be done on valves, fur­ther com­pli­cated by a need to re­move in­va­sive non-na­tive fish species • Chase­wa­ter (owned by the lo­cal author­ity for his­toric rea­sons) had is­sues with the draw-off valve, lead­ing to lengthy dis­cus­sions be­tween CRT and the own­ers over what work was needed and who should pay.

How­ever af­ter three weeks of wet weather, plus an agree­ment to op­er­ate Chase­wa­ter in the spring, Adam would now be ‘dis­ap­pointed if we run short’.

The Ken­net & Avon also has pump­ing prob­lems – and on a canal with very re­stricted stor­age ca­pac­ity, it only takes one of the se­ries of six pump­ing sta­tions from Brad­ford-on-Avon to the sum­mit to fail for there to be se­ri­ous prob­lems. CRT is work­ing on up­grad­ing the pump­ing sys­tems for the next 20 to 30 years.

Fi­nally the Ch­ester­field and the Lee & Stort (where the En­vi­ron­ment Agency had been con­cerned about low river lev­els) are re­cov­er­ing well.

But what if the ‘ef­fec­tive rain’ hadn’t ar­rived when it did? CRT was busy draw­ing up con­tin­gency plans for emer­gency pump­ing, and bring­ing for­ward planned feeder clear­ance and lock gate re­lin­ing work.

At the same time, if thought had needed to be given to bring­ing in re­stric­tions this year, then the ap­proach now would be ‘gen­tler, softer, sooner’ – and mak­ing early con­tact par­tic­u­larly with the hol­i­day hire­boat op­er­a­tors. This fol­lows some lessons which have had to be learned

fol­low­ing pre­vi­ous droughts in 2011 and ear­lier, when more re­stric­tions were brought in abruptly, or an­nounced in an un­help­fully doom-laden way. As re­gards the ac­tual re­stric­tions, com­puter mod­els can give a range of pos­si­bil­i­ties and prob­a­bil­i­ties, Adam says, but at the end of the day it’s a judge­ment call.

On the sub­ject of droughts, CRT is now work­ing to a tar­get that wa­ter­ways should be able to cope with a ‘once in 20 years’ level of wa­ter short­age with­out ma­jor clo­sures (with the Le­ices­ter Line bor­der­ing onto that level of drought). A ma­jor part of its five-year wa­ter re­sources project is look­ing at how to meet that tar­get, which canals (such as the Rochdale) are fail­ing to meet it, and what threats to wa­ter sup­plies are likely to in­crease the chance of miss­ing the tar­get in the fu­ture.

And one of the threats is the Wa­ter Frame­work Direc­tive, which is driv­ing a re­quire­ment for all ‘ab­strac­tions’ (even feeds to canals which have been in place since the canals were built) to be li­censed by the En­vi­ron­ment Agency. CRT has two years to ap­ply for prob­a­bly 250-300 li­cences (it’s not en­tirely clear ex­actly what the EA will class as an ab­strac­tion), then the Agency has three years to de­cide whether to grant them in full, to refuse them, or to grant them sub­ject to con­di­tions (such as a min­i­mum river flow be­low which no wa­ter may be taken). And although this is an EU direc­tive, it’s al­ready been en­shrined in UK law since 2003, its ori­gins are seen as go­ing back to the droughts of the 1990s and the lack of con­trol over ab­strac­tions, and there seems lit­tle chance that Brexit will bring about its demise.

An­other is­sue has been the pro­lif­er­a­tion of mari­nas in some ar­eas – and for sev­eral years now, ap­pli­ca­tions for new mari­nas have been con­di­tional an anal­y­sis of whether there are ad­e­quate wa­ter sup­plies. CRT hasn’t turned any down on wa­ter grounds yet, but in some cases has “pushed them to look at mit­i­ga­tion” – for ex­am­ple lo­cal back­pump­ing schemes, and has “come close to say­ing ‘no’ or im­pos­ing con­di­tions”.

Those are the threats to sup­plies: what are the plans to deal with them? The study in­cludes tak­ing a look at a very tra­di­tional way of sav­ing wa­ter – the side pond. These economiser cham­bers built along­side locks were once a com­mon fea­ture on canals where sup­plies of­ten ran short, but gen­er­ally went out of use some decades ago – and CRT (and its pre­de­ces­sor Bri­tish Wa­ter­ways) has tended to look at back- pump­ing in­stead of re­in­stat­ing what they felt was a sys­tem un­likely to be un­der­stood by many boaters. But now, CRT will at least look at where they still ex­ist, where they could be put back into use, and whether it would help – for ex­am­ple those on the Coven­try would prob­a­bly be lit­tle help, as the wa­ter feeds down to other canals which need its sup­plies.

But back­pump­ing and new river feeds are likely to be the main way for­ward. Adam is very aware that when he “bangs the drum for wa­ter schemes” he’s com­pet­ing for lim­ited funds against other de­mands on fi­nance whose use­ful­ness won’t just be lim­ited to once every few years. “It’s not like a bro­ken bridge or a dam­aged em­bank­ment,” as he puts it.

But sub­ject to this, his team are work­ing on de­signs on and fea­si­bil­ity stud­ies for some ma­jor schemes in the com­ing years – with the Rochdale and the Leeds & Liver­pool among the front-run­ners.

Even as I’ve been writ­ing this, the an­nounce­ment has come in that the Le­ices­ter Line is re­open­ing. Yes, it’s a fur­ther good sign that the worst is over for now - but the fact that it’s been closed un­til mid-Jan­uary is an in­di­ca­tion that there are is­sues to be faced in the longer term.

Rochdale Canal: can­di­date for back­pump­ing?

Could these old side ponds at Mar­sworth have helped?

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