To find the Exe tides reach

About tides and levels

I realise that this ‘treasure hunt’ in search of accurate history of the river and tides is a bit complex to say the least so please ‘bear with’ as I try to make sense of it (or read on about the trip we made on a sunny day in February 2022).

Harbours usually exist where a boat can reach on a high tide so as to deliver goods to the widest community with less travel by road. The quay area in Exeter has long been called Haven a word that has its origins in the work to have or grab possibly suggesting tieing up but also from the norse word haf meaning sea which might suggest tides reach. The high tide would have reached above the present Quay area to where the old long bridge was. This may be borne out by sea related sediment in that area. Tides reach would have changed with the weir apparently built by Isabella de Fortibus in 1272. Interestingly the stone bridge which lasted well into the 1700s as a working bridge was built before the weir in 1190 and therefore must have had to make some small adaptions to the new level of the water after the weir. The Bridge may have been the original high water/tides reach mark.

An unanswered question (for me) is exactly where original wooden Countess Weir was. One account suggests that the first Weir was not hers but that of Baldwin de Redvers and was a fishing weir presumably designed to create a pool for netting or angling. Shore-based drop and lift nets (a hinged crane lowering a horizontal net in to the river) existed until the late 1700s. A fishing weir would not need or want to close the river, only to slow it down, so this fits with the description of a weir with a gap as Isabellas has been described.

So when does the idea of a mill first come in and where would the leat be? A weir (Isabella and Redvers?) was blocked by Hugh De Courtenay (Isabella’s nephew) after an angry dispute with the City of Exeter appropriately about fish. Hugh’s motivation by blocking the river completely may have been threefold: to improve fishing for Topsham (then a parish reaching further up towards Exeter), to cut off shipping trade to Exeter and thereby to increase wealth in Topsham (and to spite he citizens of Exeter!). I.e. not initially to service a mill so perhaps looking for a mill or leat at this stage might not be useful? The story is often told of how Isabella’s motive was for her mills but so far I have found no evidence of mills or leats at that time. It would have needed to guide the water to a leat and a mill and it’s height would be on or above the highest point of a high spring tide. St James Weir has this height and position so it could have been exactly where St James weir is. But there is another leat lower down starting just upstream from the Countess weir Bridge. However to hold the tide from bursting it’s banks onto the land around would probably have been more dificult from here and the ‘lake’ or pool above would have been much bigger/longer reaching all the way from the Countess Weir Bridge to the quays in Exeter. St James Weir is an obvious corner to put it on though. Weirs work well at corners directing the flow to the leat and taking pressure off the dam. I am not sure which leat was used by the Countess for her mill if indeed it was for a mill and not fish but if we did know this we would surely know where the weir was. Wooden construction has been found at St James Weir but this may not be old enough to indicate the Countess’ weir which was apparently made of wood.

David J Solomon wrote in A History of Fish and Fisheries of the River Exe (pub 2012) that a possible location for the original Countess Weir could be just upriver from the Countess Weir bridge. His book shows an excerpt from an 1830 map which shows the site of the weir (therefore conjecture then) and his book also shows a photograph from the 1890s showing piles of stone just below the Countess Weir bridge and the suggestion is that this stone was what is left of the Countess’ weir.

To summarise; a possible progression of weirs:
An unclosed weir or weirs (30ft gap) probably for fish was/were in existence made by Baldwin de Redvers around 1239 and/or Isabella de Fortibus around 1272. So far I dont know where these were.
After a dispute with the Exeter mayor Hugh de Courtenay fills the weir initially with big trees thereby blocking trade/shipping (1312). Note: it is described as bulding between two existing weirs which confuses the issue of whether he blocked a narrowed gap effectively between two piers coming out from either side. or built a new weir between existing weirs.
Edward Courtenay (Hugh’s nephew) then made two more weirs one at St James and one at Lampreyford (I think this may be just below Trews weir so higher than St James). This action closed the port of Exeter and casued the surrouinding fields to flood with sea water from time to time.
Any weir, once starting to decay, will have been dispersed by many floods over the years.

Apologies for this simple diagram which only refers to the 2 main weirs!

The results/what we learned about the tides: High tide on a big spring tide (without recent rain) means the flow of water at the weir (in its current broken state) stops, going neither in or out. The day after the highest tide it continues to flow down through the narrows at the weir but only very slightly and the levels are pretty much the same above and below the weir. Rain and a bigger river flow would change the height above the weir and make it hard to paddle beyond and there would probably be some turbulence in Salmon Pool where the river would be risen under pressure from the tide. But would the level be the same or greater due to pressure coming downstream?
If the weir were not broken we would have had to drag the kayaks over the section of the weir nearest the west bank because the height of the weir when intact was for the very highest of tides, about 4 foot more than the tide we came in on.
We, and maybe the salmon, were happy about the break in the weir. However it probably needs to be repaired as flash floods are more common these days and the break will continue to erode thereby lowering further the water between the St James and Trews.

Trews weir as we saw it from below is about 2.5 to 3 metres above the high water mark at St James weir. This is a very rough guess but it means that navigable water in Exeter, if the tide did reach just below the old stone bridge, would have been 3 metres below where the the current level is now say at Exeter Quays.

So I say the Romans would have been able to get boats to just below the city wall where the Customs house and Cricklepit Mill are but any remains of Roman docks would therefor be submerged and presumably built over. A natural stone ledge has been said to have been used as a dock by the Romans at this corner of the river where the geology may have created a deep water pool due to a narrowing of the river below where the old long bridge was. Note that it is only after the building of Countess Weir that the river silted up from the quays to the weir. At the same time the reclamation of the 2 islands at the old stone bridge in Exeter (Exe Island and Shilley Island) would have narrowed and deepened the flow at the bridge. But we do know that the Romans’ main port was at Topsham where goods were unloaded for transport to Exeter.

I also learned that the tide times are the same for Exmouth Docks as Exeter and that this may be explained by the way the tide puts pressure on the downward flowing river; in other words it doesn’t have to reach it to raise the level.

Our trip there and back

Our trip started early leaving Topsham Quay at 8am for a high tide of 9.20 at wherever it occurred. My companions were Hazel McCabe on kayak and Christine on paddleboard.

It was mirror still with the sun catching to tops of the reeds, an as above so below day and we felt like we were paddling above or in the sky! Above the bridge the M5 temperature lowered especially as we passed through patches of mist clustering around the reeds. The sewage works become apparent on the left/west opposite the reed beds and the smell was one of soap mostly. We noticed the sewage smell more on the way back. It is a feature of the area.

Out of nowhere and quite quietly we were suddenly joined by Dave McCabe in his motorboat which now became the safety boat! Approaching the Countess Weir bridge in the sunny stillness was beautiful. It is best seen from the water. The west bank is open park for a good long sections here and feels rural and remote. Most walkers don’t make the water edge her preferring to follow the route that passes Double Locks. Just after the bridge are some houses in exceptional waterfront positions. A sharp left occurs after the houses at a point where the Northbrook end of the mill leat comes out. We saw our first king fisher here. The pedestrian bridge at a corner hails the proximity of Salmon pool. Just after the bridge the overflow channel that has been beautiful rewilded with diverse resilient plants is gently filling up from the river. It also fills dramatically when Trews weir overflows under pressure after rain and then dries into little wildlife sustaining pools in the summer.

The day before our paddle I met a woman at St James weir with extraordinary footage on her phone of a seal holding a large salmon. We were hopeful the seal would be there beside us in the water but it didn’t show up. Seal sightings are not uncommon and I heard from 3 people who had seen it in the preceding two days. I am still hoping the woman with the footage will send Tidelines her footage as salmon are something we are researching just now. Here is what I saw pretty accurately I think:

Commercial salmon fishing is currently banned on the Exe in the hope of increasing the numbers. In short salmon all over the world are in steep decline. Some causes are climate change with higher sea temperatures making food harder for salmon to find at sea and lack of oxygen in the river water from pollution and agricultural run-off. I have drawn what i saw on her phone. In her video the seal’s head was above the water but it’s body was very clearly visible below as was the salmon which was very light in colour either because it’s belly was facing us or it was old and dying. And it was a film so the seal was gently moving about.

The broken weir means there is a gap nearest the east side which has had a drop of giant stones to prevent further damage to the shore and parkland there. The leat that leads to mills further down is blocked here. Dave took his boat which has a draft of about 2.5 feet up the weir with ease. We followed and had to work quite hard for the first time! But it calmed down after 30 yards.

It was 9.20am, high tide in Exmouth and at St James Weir. We paused 500 yards upstream from the weir, tying up to a tree, before we decided we might as well see how far up we could get from here. The concern was that Dave’s boat might struggle if the tide now dropped leaving a torrent at the weir and there are unforgiving rocks there. Dave went 100 yards further upstream til he met unpassable shallows. The paddlers explored further all the way under the pedestrian bridge just before Trews as a kingfishers darted back and forwards across the river around us. With any rain Trews might be more difficult to reach but though noisy it was calm and we were able to pull up either at the reeds or by the shore without being in any danger.

Just before we reached Trews weir I had noticed wooden piers sticking out from where I think there are allotments and they were significantly higher than the river illustrating that the breakage in the weir has meant quite a drop in the water level above it. From the pic above you can see a banks of brown/dead vegetation which may be the height loss after the weir broke. It might also be flood levels but our trip was after quite a long period without rain.

We headed back. Dave had passed the gap at St James weir and parked up against it on the other side. No log flume for us paddlers but a little more flow than on the way up.

The whole trip took about 3.5 hours. Conditions were probably as perfect as they can get.