Monday, September 22, 2014

Severn Boats and Bores - September 2014

The Severn Estuary and Gloucester & Sharpness Canal
 8th - 12th September 2014

The Severn Bore at Epney, 11/09/14

During the second week of September, I grabbed a few days away walking and sketching along the Gloucester & Sharpness Canal and Severn Estuary in Gloucestershire. A time consuming, fiddly journey by train and coaches (especially heading home on the Friday), but I was keen to revisit the Purton Boat Graveyard and Sharpness.  Being spring tides just ahead of the autumnal equinox, I had another chance to view the Severn Bore.

I was based at Wild Goose Lodge at Shepherd's Patch, on the Gloucester & Sharpness Canal near Slimbridge Wildfowl and Wetlands centre. I'd had three stays here in the 2000s and was disappointed when the hostel closed in 2008, Good to see it living on as WGL. It seems to be most popular (and usually full) at weekends with big gatherings, but while I was there during the week it was fairly quiet. It's much as the YHA left it, including the more affordable pricing. There is a wild goose residing by the pond at the back, though on the Wednesday morning, he / she didnt take well to the a cormorant swooping down into his private pond / patch.

Ripe berries along the towpath
Particularly after the unsettled August and not much in the way of wet weather options in the vicinity, I was relieved when the back-to-school change to drier, more settled weather came. The early mornings walking along the Canal tended to be misty or foggy, with an autumnal feeling; once the sun had burned through the mist it was very warm. All the berries were ripening, with a feast of blackberries all along the towpath.

Purton Boat Graveyard and Sharpness

I had two days here, first the Tuesday (9th), beginning with  leisurely stroll along the GS canal towards the southern end of the canal at the old harbour entrance at Sharpness. I got lots of sketching done, though on the Wednesday, tidal conditions dictated what I did first and took me by surprise.

I headed out fairly early on both mornings, it was misty / foggy, especially the Wednesday when the Cotswold escarpment was fogged out on the eastern horizon. To begin with, it was very damp underfoot with the dew, though it quickly warmed up and dried out as the sun burned through the mist. It remained very hazy all day, particularly on the Tuesday when I couldnt see the Severn motorway bridges from Sharpness, unlike when I was here before. The afternoons were very warm.

Milepost along the canal
Leaving Shepherd's Patch, I crossed the swing bridge to get to the towpath on the western side of the canal. Mileposts along the towpath - north side G for Gloucester, south side S for Sharpness. 4 miles each way between Shepherd's Patch and Sharpness. Early in the morning it was very quiet along the towpath, but for a few swans on the water.  Boats and trees mirrored in the still water. Nearer Slimbridge, the distant roar of the M5, otherwise very peaceful.
Foggy morning on the Gloucester & Sharpness Canal, 10/09/14

At Purton, two more swing bridges, by the first one, one of the keeper's cottages, with characteristic temple-like façade, characteristic of this canal. Beyond here, a row of cottages. 

Bridge keeper's cottage, Purton


From there on, the canal ran very close to the river. To protect the canal bank against the Severns powerful tides, there are some unusual defences in place: Between 1909 and 1965, numerous boats were deliberately beached here, having served for many years along the Severn estuary. These now form the Purton Boat Graveyard. Many of the boats, particularly the timber framed ones, are rotting away, the ironwork rusting, though the concrete lighters are well preserved.  Id been done a number of studies of this during my trips here in the 2000s. Since then, British Waterways and local groups have added new touches to better inform people of the recent history of this part of the estuary and what the place is all about.

" The Final Resting Place" - " The final journey of numerous barges, schooners, ketches and concrete lighters was to be beached on the banks of the Severn" . These were words on the column listing all the names of the boats in the graveyard, among them The Dursley, Edith, Envoy, Mary Ann, Selina Jane. Behind the column, the tide was now ebbing strongly. All the boats, even if only a few rotting beams remaining, are now marked with little plaques, with key details such as when and where made, many at Sharpness, and when they were beached.

Near the column, in front of the view south along the river towards Sharpness was a plaque commemorating the 50th anniversary (2010) of the railway bridge disaster which occurred on the night of 25th October 1960. A bit further down the canal was stone turret and on the far side of the canal a pillar. This was where trains crossed the swing bridge over the canal. Next to it, the Severn and Wye Railway Bridge which spanned the Severn here until demolition in the early 1960s. Another new information board here outlining its history.

Chris Witts gives a full account of the fateful night in his book Disasters on the Severn, but essentially thick fog and a strong incoming tide meant boats were finding it harder than usual to enter Sharpness Dock. Two tankers, fully loaded with petrol and fuel oil, missed the harbour entrance and drifted upriver with the tide towards the bridge. One of them, the Wastdale H collided with column 17, rupturing its petrol tanks. Then, the Arkendale H collided with the Wastdale. The collision caused two of the bridge spans to collapse, rupturing a gas main and electric cable. Then there was a big explosion as the petrol spilling out of the tankers ignited. Flames spread across the river. Three of the eight crew swam to shore, but the other five were killed.

The view from Purtong towards Sharpness at low water, 10/09/14
On my way back this afternoon, the low ebbing tide revealed two tankers out in the river to the south, probably the remains of the fated tankers. With recent history in mind, there was a sobering, eerie to this part of the estuary, even in the bright weather. As I sketched the view towards Sharpness, warning quotes came to mind:
 
Purton Boat Graveyard
Respect the water (RNLI)
You don't want to be down there when that tide is running
Respect Sabrina and she'll do you the same,
Abuse her and she will most certainly abuse you.

Busy railway line on the far side, with a couple of freight trains. Sound of their passage and whistles carried across the water.

Continued on to the end of the canal, at the old harbour entrance and Severn Area Rescue Association (SARA) lifeboat station. Had lunch here and sketched the harbour wall. The shadow against the light, its reflection in the pool of water caught behind the sandbank piled up and curving round the wall. The height of the wall went to show how high the tidal range is here (10m+ on high spring tides). There were strong currents in the middle of the channel as the tide continued to ebb, the estuary narrowing here. Ever changing wave and flow patterns. Some large sandbanks became exposed, the Ridge Sand prominent just north of the harbour. The water now becoming more reflective towards the far bank as relative calm ensued nearing low tide. Downstream on the far side was Lydney harbour wall.

Purton Boat Graveyard


Sharpness - old dock entrance and sandbanks





Sharpness - the present dock entrance


Artist twarted by the high tide 

On the Wednesday, I thought I'd return to the Boat Graveyard and focus on sketching there. 

My sketches are on my art blog

Tidal currents in the estuary viewed from Purton as the tide ebbs
 I left WGL just after 8:00am and by half-nine the sun had burned away all the fog and it was quickly warming up. I got to Purton about 9:20am and found, to my surprise, the tide still rising, the estuary full and the current moving upstream, though not at full pelt. It appeared to be slowing down, tending to the highwater slack, but when I got to the "Final Resting Place" post, I found the water lapping over the concrete lighters beached here. You can't be too careful with tidal rivers, most of all this one. The Boat Graveyard would have to wait. Though I'd noted the bore times at Newnham I didnt looked up high and low tide times until this evening. The predicted bore times for this morning at Newnham, Epney and Minsterworth were respectively 08:35, 09:15, 09:35. High tide at Sharpness this morning was 09:34 (see Tidal notes section).

The high tide laps onto the bank and over beached concrete lighters at Purton Boat Graveyard, around 9.45am, 10/09/14



Below - The same scene after the tide had ebbed during the afternoon, around 3.45pm, 10/09/14





For now, I carried on past the railway bridge remains and instead sketched the view near the old swingbridge tower looking towards the SARA lifeboat station / wall of old dock entrance. I knew I had to get the essential things such as the water height down quickly. By 10:00am , the flow had slowed virtually to a stop and would soon be turning. The high tide was up and over much of the saltmarsh alongside the canal. The water was filling up a channel between the canal bank, with a beached iron boat amid the reeds, and rushes growing on a mud bank separating it from the main channel. Ten minutes later, I saw a seagull on the water here, drifting downstream as soon as he stopped paddling. Then the ebb quickly gathered pace. I think the birds gave up trying to keep up with it and flew off elsewhere. Even this close to the shore, the current was racing along. I noticed the water level visibly dropping. By 10:46, all the water had gone from this near channel, as far as I could see, leaving behind a wide bank of reeds and saltmarsh grasses.

View towards Sharpness from north at 10:00am, 10/09/14

Lower water, around 3.30pm, 10/09/14

By midday, I knew I could safely knuckle down in the boat graveyard now. But I hadnt thought about the mud. The path at the foot of the steps was still wet. As it was so warm, I thought the path through the boatyard would be drying out by now. It was gradually, in the sunnier bits, but not in the longer early autumnal shadows of the hedge separating the riverbank from the towpath. I was relieved I'd worn my trainers and not my (still fairly newish) sandals. Even in the trainers, I had to go carefully: there were puddles in places, the though not deep, the wet mud was slippery, grass still very wet, too. Having fallen over a steel rod sticking up on the beach near Solent Breezes, last week, I was extra wary here. I plodded through beyond the halfway mark. By now, I was getting hungry and needed my lunch. I sat on my rucksack in one of the drier spots, only mud / tide which to narrowly miss at least two dollops of dogs muck,. That got me more than the goes with the tidal mess.

Before knuckling down to the boats, I doodled, making notes reflecting on the Severn and its tides. The water here, though well down on earlier, was still high, covering the sandbanks in mid-stream here. An angry looking channel of turbulent, choppy, very fast flowing water. Everything considered, especially its tidal regime, I'd say the Severn is the most dangerous river in Britain, though Morecambe Bay probably vies with it for the most dangerous estuary. The Severn estuary has the biggest tidal range, as much as 14m at Beachley, one of the largest tidal ranges in the world. It undoubtedly has the fastest tidal river current, be it the rising tide behind the Severn Bore, or the vicious currents in the open estuary, clearly capable of ramming tankers against bridges. 10 knots or more wouldn't surprise me here. Outside the tidal reaches, there's a dangerous stretch through Ironbridge Gorge and it is, of course, very flood prone. Probably in one of Chris Witt's books, I picked up this saying:

Respect Sabrina and she will do you the same. Abuse her and she will most certainly abuse you.

The tidal Thames needs respect enough, with a spring tidal range in central London of around 7m and currents a good 5 knots at full pelt.

Despite the mud etc., I did two sketches here, which I was quite pleased with.

Now early afternoon, I headed back to the old dock at Sharpness and up on to the green area above the cliff, view of harbour wall, of timber or steel girders, at the present dock entrance. Did a circuit of the road past the working dock area, though didn't find an ice cream / refreshments, at the Chandlery in the canal marina or elsewhere.

From about 3pm, I took a leisurely wander back along the towpath. The tide, was now right out, revealing broad sandbanks. All the concrete lighters at The Final Resting Place now high and dry. Ridges of rock exposed in the river bed. Birds wading. Finally a sense of calm in the estuary. Until the next tide

Severn Bore and Severn Tides

Epney - Thursday 11th September

Surfers await the approaching wave, Epney
Still very warm, though less misty than yesterday and cloudier in the afternoon, making for a bit more of an autumnal feel to the Severn. Left WGL at 7.00am. As I left Shepherd's Patch, a red low sun was rising out of the mist to the east. I had the towpath virtually to myself, though I startled a heron on the water. Distant geese flypasts. Past Cambridge Arms, Splatt, Fretherne and Church Lane bridges. All swing bridges. At Fretherne, two large pylons loomed out of the trees. On far side of the canal, factories / warehouses, a high tower of what looked like an old factory. Across Church Lane Bridge, a marina and narrow boats all along the canal. At Saul Junction, a big crane rose above the boatyard. Just beyond here, the Junction House lock keeper's cottage where the canals met. Left this for a look round on my way back later. In the meantime, I took the path from the junction roughly following the remnants of the Stroudwater Canal towards Framilode to join the road round to Epney. This was a very narrow, very overgrown path.  Got wet trainers and trousers amid the dew clad long grasses and weeds. Both soon dried out as things warmed up by the Severn. Pinned on one of the stiles, a photo of flooded fields, beneath it, a few words about the flooding here on 3rd January, during this year's first double fluvial-tidal flood whammy on the Severn. Field here covered with 94 million litres of water, apparently. Wonder how they measured that - field area × depth of water measured by how it came up some bloke / shed, maybe?
 
Pylons reflected in the canal, Fretherne
The road to Epney had no footway. It was very winding and there was traffic than I have liked, particularly walking back. A fair few Chelsea Tractors, SUVs and various vans. Though part of the road ran alongside the river, there was no public right of way along the river between Framilode and Epney.

Through Epney itself, the road ran alongside the river, two lanes, as far as The Anchor pub. No footway alongside the wall where most of the bore viewers congregated. People parked along here, too, blocking lane. Though this location, offered a clear view downriver - further than Minsterworth, I wouldn't have liked to have come here by car and faffed around with parking. As far as I could see, the only off-road parking was at The Anchor, about the same size car park as the Severn Bore Inn. There was a public right of way along the riverbank beyond the pub, but didn't explore that. Generally, there wasnt as much space for people to gather as at Minsterworth where bore watchers could spread out along a public footpath running along floodbanks.

The bore wasn't due at Epney until 09:56 BST. I arrived 90 minutes early after walking about 6.5 miles from WGL . With calm, settled weather, fairly high pressure and very light easterlies, it was unlikely the bore would be early (it can be 20 minutes early). I wanted to allow at least two hours to be on the safe side, not knowing what to expect. I wandered towards the pub, passing an older guy parked up, by the wall making calls on his mobile. Though the pub had a large garden with picnic tables, the view looked a bit restricted by trees. Didn't fancy standing along the road, by the wall. Instead, I sat down on the low wall in the small green area at the southern end of riverside. It was off the road, clear view downriver towards Framilode, hills of the Forest of Dean hazy behind. Behind the wall, a bank if reeds and rushes. The good thing about this setting, as opposed to a floodbank in an open field was no one could barge in front and block the view like that guy at Minsterworth six months ago. Only other sign of life here to begin with was someone's bicycle and a sleeping bag.

I passed the time by doing a small sketch of the view downriver, looking towards a sandbank on the inner bed on the far side where gulls congregated. Later I added one or two surfers. Though much wider than at Minsterworth, there was more of a tidal river feel than an estuary, with water all across the width of the channel. The water was fairly calm, a fairly gentle flow downstream.

The surfers began arriving from about half-nine. "Where is everybody? Yesterday it was really busy. " said one of the earlier arrivals as he clambered over the wall and down the bank into the water. I didn't know how busy it would be this morning, though being a weekday morning, I didnt expect it to be packed.  I noticed later quite a few people parked up along the road watching, though most of them seemed to be the surfers.

As the surfers waded out into the water to wait for the tide, they went to show just how shallow the water was. In places only knee height, waist height in the middle of the channel. Someone commented that the flow was slow. In the still air, the sound of their pre-bore banter carried - "Come on Irene!", "Done this one before?". The two paragliders were a bit noisy, though.

Nearer the due time, a few more people gathered near me, the guy here when I arrived, a lady in running gear, the lady with the bicycle. I first saw the white of the breaking leading wave at 10.04h, as it appeared after rounding the bend in the distance (eight minutes late better than some bus / rail services Id care to mention). The guy asked if I'd been here before. The runner said she was racing the bore on 6th October, part of some event in which runners try to out run the bore. According to Rowbotham, it runs at 8-13 miles per hour, so a challenge at the higher end. Perhaps that's what the people running with torches were doing that night last year when we were with WOUGS at the Severn Bore Inn.




White breakers each side of the leading wave, the longest one on the far side. As waves go, it seemed to approach fairly slowly, though it seemed much quicker as it passed us. The breaking wave on the far side widened. A row of a dozen or so surfers rode it. Could only see the breaking on the near side further down because it was hidden by the reeds, though I could hear it beneath the waves as it passed us. The wider river here made for a shallower leading wave, with numerous smaller ones behind, some of them breaking. The height of the leading one was about 50-60cm. Afterwards, along the road, I heard one of the surfers say it was "mediocre", about 6" higher last night, but he was probably a seasoned bore surfer. To coin Jeremy's phrase last year with WOUGS, I was more than a bit impressed. Certainly higher and more pronounced than that one at Newnham that time (2006, again WOUGS). I'd enjoyed watching it and came away feeling it had made my day.


Turbulence in the Severn as the tide rises at Epney during the hour after the bore



I didn't head off immediately. As we've seen before, most people lost interest once the wave has been and gone and drifted off. I though, hung around to watch the rising tide following on behind it. In many ways, it was just as impressive, for the rapidity, turbulence and sheer volume of water. Once the bore had gone, it quickly gathered pace. Half an hour after the waves (10.35), it peaked it in speed and roughness. As at Newnham, there were shoals of smaller waves and rollers. Near the gauge and ditch coming in between it and the pub, a secondary current ran and joined up with the main one. About 45 minutes post-bore, it began slowing down, though the flow ran upstream for sometime afterwards. I suppose as the river was wider and more open than it had been at Minsterworth, the change in height didn't look sensational: nowhere near overtopping the bank on the far side, though there nonetheless. As the water slowed down, the seagulls on the water appeared content at their more leisurely journey. Earlier on, it looked more as if they were been forced to move faster than they'd have liked High tide, appeared to be around 11.15, seemingly coming to a stop during the next five minutes. By half-eleven, there was a slow but sure drift downstream. Ebb current building by 11.45am. It didn't stop long, then. Where I'd been watching, the high tide got to just below the pear trees. The lady with the bicycle was still there. She tried one and offered me one. It was sweet and very tasty. We chatted for a bit, comparing notes on the bore, youth hostels and independent hostels (I mentioned I was staying at WGL). I spotted May Hill across the river to the west.

My shadow in the Severn - my new take on the "selfie"

High tide at Epney - and pears growing wild

 At about midday, I went back the same way to Saul Junction, the narrow, overgrown path, by now fully dried out in the sunshine. At Saul junction I sat on the bench near the canal junction and swing bridge watching narrowboats come and go, looking up the eastern arm of the Stroudwater / Thames and Severn Canal. This canal runs for 28 miles from the Thames at Lechlade to the Severn at Framilode. A pleasant contrast to the turbulence of the tidal Severn.  On my way back towards the Church Lane bridge, I found a handy café, the Stables Café . By now hungry after my early start, I relished my slice of lemon sponge and mug of tea.


Saul Junction







I then followed the towpath back to Fretherne, , detouring onto the Severn Way near Fretherne Bridge to view the Severn from Hock Cliff. A windy, fiddly walk to the riverbank through woods and fields. Much of the cliff itself was wooded, so not much of a view. A better view from  the open field on the east side of it and along the floodbank lower down. By now it was cloudier and mistier with a more autumnal feel, though still very mild. The river was much wider here than at Newnham, Epney or Sharpness. An interplay of light sparkling on the water, sand banks grey against the light, textures formed by ripples, rivulets etc. across the sand and mud. Rays of sun shone through the cloud. Sharpness harbour wall and hill behind it visible downriver in the distance.

Views of the estuary near Hock Cliff





After sketching an impression, headed back to the Canal and along the towpath. Back at WGL about 5.45pm, pleasantly tired, and fulfilled.


Stonebench - Lower Rea - Friday 12th September

A very time consuming journey home for the mileage this afternoon and evening. Everything running late, starting with the Severn Bore.

I checked out of WGL fairly early, just before 8:00am and began walking briskly along the canal towards Gloucester. It was a 12 mile walk. My rucksack was still heavy. I wanted to get to Gloucester in time for something to eat, before catching the coach to Bristol and begin my journey home. The weather was overcast, the sun not really breaking through until about midday. All in all, then, I wasnt as serious about seeing the Bore as Id been yesterday and didnt feel like big detours from the towpath. It was predicted to be three-star, the tidal cycle having peaked on Wednesday night and now on the wane. Nonetheless, the river was only a five to ten minute walk from the swing bridge at Lower Rea, so I thought Id give it a go if I got there on time. I thought it would be tight: I didnt know the bore timings for Stonebench, so I aimed for the 10.55h predicted at Minsterworth, about 2.5 miles downstream on the far side. Though about 40 minutes later than it would have been yesterday, I had 9 miles walk from WGL to get there.

North of Saul Junction, canal quiet in terms of narrowboat traffic. From Lower Rea bridge, a short walk left along a lane to the river. The road continued left, alongside the river to Stonebench. I turned right onto the footpath past a couple of houses and parked myself on the riverbank, just past the next hedge. The Severn was much narrower here than at Epney looking more like a tidal river than an estuary. It wasnt an ideal viewing point, with trees all along the bank preventing a completely clear view downstream. If Id known Id had more time, Id have looked for somewhere better. I knew I hadnt missed it: the water very slowly but surely moving downstream. With the bus etc. in mind, I was watching the clock more than yesterday. As at the Severn Bore Inn in the dark last year, I thought I could see tantalising tricks of the water or light which might indicate the breaking, leading wave, or something more subtle, but they weren't. Had the tide turned after a so subtle wave, so subtle that I blinked and missed it?. At 11.18, a motor dinghy came upriver. I wondered could that be it, a small, subtle bore lost amongst the wash it generated. If the pressure had risen further overnight, there was a chance the bore could have been smaller than predicted. By half eleven, I wondered if it was stuck somewhere (like my bus later in traffic). It couldn't be right - you cannot change the laws of physics...

Then, at 11:40 by my watch, just as I was about to head off back to the canal, it came, with a rush and lots of noise. Maybe it was not having a completely uninterrupted view downstream that made it seem more sudden than before, though it does move faster in the narrower river than in the estuary. I didnt see it break on the near side, where it was well below splash height, but it made lots of noise, the water swirling in its wake.. It was indeed a fairly small bore, with 2 or 3 waves, with little or no white crest on the leading wave. Nonetheless, caught out by the timing, it took me by surprise and made me jump.


Gloucester docks - nearing the end of my walk along the Gloucester & Sharpness Canal



Background to the bores and tides

After the surprises described above, I checked of online tide tables while away and had a refresher on the tidal regime in the Severn Estuary as a whole (Rowbotham, 1964).  

Little Rissington, weather station nearest Gloucester, 17:00h Wednesday 1021mb, 1023mb, rising on the Thursday evening. If I remember rightly, this would lower highwater by about 10cm.

High tide at Sharpness dock on Wednesday morning was at 09:34h BST, predicted 10.5m (Hydrographic Office, online tide tables). Low water was 18:42h, 0.7m. On Wednesday night, HW 21:54h, 10.9m. Five star Severn Bore predicted. Apparently, there was a good turnout even though it was dark.
Thurs 11th: LW 07:03, 0.7m, HW 10:16, 10.5m. Four star bore predicted. LW 19:23,    0.7m, HW 22:35,  10.7m

Full moon was early Tuesday morning, 09/09/14, 01:38h GMT. This was another so-called supermoon, i.e. full at perigee, its closest point in orbit to the Earth. Therefore it looks bigger and brighter than usual in the sky, particularly when nearer the horizon. It makes for higher tides, too.

In anticipation of potential tidal trouble, the Environment Agency had a few flood warnings and alerts out. On Wednesday evening: 8 FW, including two on the tidal Wye, though tidal Severn Gloucester-Sharpness was on a lower flood alert. Predicted high tides
Epney Wed night 6.3-6.5m, 5.9-6.1m Thurs am.

Timings of bore relative to HW at Sharpness (p52) under average conditions of weather etc.:

Epney - subtract 20 minutes
Upper Rea / Stonebench add 15-20 minutes; Minsterworth - subtract  3 minutes.

Need a high tide of 9.5m+ at Sharpness for large bore (3* or better).

Rowbotham has a good snapshot of what the tide is doing along the estuary at a particular time (Fig 3, p25) during a high spring tide. Theres a point when its high tide near the middle of the estuary (around Newnham and Epney)  and the tide is ebbing at both ends. The tide is ebbing at Sharpness Dock and everywhere downstream of Newnham. Meanwhile, the bore, prelude to the rising tide, is travelling upriver beyond Minsterworth towards Gloucester (Maisemore), running against the ebbing tide there. At 09:34h Wednesday, then it was high tide at Sharpness. By then, the Bore had passed Epney ( due 09:10) where the tide was still rising. The bore would have been on its way to Stonebench (09:49) and Maisemore (10:04) where the tide is still ebbing. On the Friday, the bore was due at Minsterworth 10:55. HW Sharpness was 10:58. From the timings above, the bore would have been due at Upper Rea 20 minutes later, 11:18h.  The bore can run up to 30 minutes late, so 22 minutes late wasnt unreasonable.

Factors affecting the timing and height of the bore: wind strength and direction; atmospheric pressure (in the Atlantic off SW England); the amount of freshwater flowing downriver; shifting channels / sandbanks in the estuary.

High barometric pressure will decrease the bore height, delay it. I dont know where the high was centred, but around Gloucester it was above 1020 millibars on the Wednesday and Thursday. 
The winds were easterlies, though they were generally very light. Strong northerlies and easterlies would reduce the height of the bore and delay it, whereas strong westerlies would raise it and make it arrive early.

According to Rowbotham, the optimal amount of freshwater flowing downstream is 0.75m below Gloucester, apparently. Too much (e.g. winter 2014) decreases the height of the bore, especially upstream, as during and shortly after the fluvial flooding last winter.  High freshwater levels may make the bore arrive earlier. At the end of the summer and into a dry, mild September, river levels were low, though I dont know whether they were low enough to decrease or delay bore.  

Easterlies September 2014 were light, so atmospheric pressure and low freshwater level in river were probably more dominant factors, though maybe water level a bit too low at the end of the summer and predominantly dry weather since the floods receded in March.

From The Port of Southampton tide table, changes in the height of the tide relative to the astronomically predicted height: 1025mb  subtract 0.1m, 1035 subtract 0.3m. From 1015mb down, the height increases by 0.1m for every 5mb fall in pressure.

References and Weblinks

Books

Fred Rowbotham, The Severn Bore, David& Charles (1964)
Chris Witts, Disasters on the Severn, Tempus (2002)

Websites

Severn Bore timetables
Accessed 19/09/14. On the blog page, a video with good footage around Epney of the bore on the Friday, though Im not sure I approve of the use of drones. If their use became widespread anywhere and everywhere, there would be no peace or privacy, even in open spaces such as this. Future walks along the Downs being ruined by a drone delivering someones pizza?
You Tube link: https://www.youtube.com/watch?v=QFvM4OClnJs



Blogs from March 2014 about the Severn Bore and Gloucestershire area:


Review of Wild Goose Lodge 
Shepherd's Patch, Gloucestershire - Wild Goose Lodge website

A good enjoyable stay. I'd highly recommend to anyone  visiting the Gloucestershire area, particularly on a budget. Hope to be back again.

4-5*
Value for money *****
Double Room (room 7)- ****
Food (evening meal) - ****
Friendliness / helpfulness / efficiency *****

I was attracted to Wild Goose Lodge for its pleasant location near the Gloucester & Sharpness Canal at Shepherds Patch near the Slimbridge Wildfowl and Wetlands Centre. I was there for four week nights during the second week of September, walking and sketching along the Canal and Severn Estuary.

Formerly owned and managed by the YHA Slimbridge, this is now run as budget accommodation catering for groups, families and individual guests. They have a mix of double rooms and bunkrooms. In 2014, the prices were respectively £45 per room per night for the ensuite doubles, £40 per room per night bed only but washroom / showers / bath nearby; £20 per person for bunk rooms. Aside from the addition of the more comfortable doubles, the place was more or less as the YHA had left it, with self-catering area and dining area downstairs, the same furniture and crockery. The prices per comparable with the YHA. Having a good, well-equipped self-catering area makes a big difference when travelling on a budget, though they do main course evening meals, £9 per night. Mine were all very filling, particularly the lasagne on the first night and pasta dish on the last. They do breakfast for £4.50. There is pub nearby, too.

Id Strongly advise self-caterers, to bring all the food they need with them (heavy rucksack off the bus from Gloucester, for me, then) as there is very little in the way of shops within walking distance of the Lodge: just a small shop nextdoor to the Black Shed café at Shepherds Patch (open 9:00am 4.00pm). I got the last pint of milk there, but it seemed to have a very limited stock.

In my room (no.7), the bed was very comfortable. Plenty of cushions. The only thing I will say was it might have been a bit cramped for a couple: the bed was only accessible from one side and there wasnt very much storage space downstairs. That said, I thought £40 for the room was very good value (the going rate for B&Bs in southern England now starting from £40 per person). There is a boot room / drying room laundry area downstairs with storage space. Towels are provided in the doubles.