Certainly centre stage this week has been the canal in Swindon. Two consultations are about to, or have closed on various aspects of Wichelstowe. The WBCT engineering team which met this week are looking at what kind of culvert would be best to go under the M4. To tunnel under the M4 and not interrupt the motorway traffic is a challenge- you may have seen elsewhere a few years ago at Maidenhead where a temporary diversion of the carriageways was made while construction took place. Unfortunately this is not an option for us as the nearby railway line prevents the diversion .The solution will most likely be a jacked box section where a preformed box is forced under the carriageways and then the materials removed. The added challenge at Wichelstowe is that there is a requirement for a road crossing too and we continue to discuss with the Swindon Borough team how both tunnels could be built at the same time , or preferably a single tunnel for the road and canal.
Jacked box at J15a M1 (Images courtesy Robkins)
WBCT is keen to also discuss the canal link from the M4 south west to Hay Lane -this area is part of the Wichelstowe project but allocated for 'green space' but in engineering terms important as the masterplan will re-align the Wharf Road/Hay Lane junction.
Looking at another long term project, if you have been to Coate Water in Swindon in the last week you may may noticed that the water level has been reduced to allow some engineering works. You may be aware that Coate Water was built by the Wilts & Berks Canal Co to supply water to the canal (originally through a feeder stream that joined the canal near Greenbridge). The revised route for the mainline of the canal now passes close to Coate Water so it would be very useful to return the reservoir to its original use but there is of course a snag!! The reservoir was extended in the 1980's with a new section to the South East- the two sections being divided by a dam structure- this in itself not a restricting issue as when the water level falls in the main reservoir the new section stays at the retained level. The real challenge is that the whole reservoir is designated as a Site of Special Scientific Interest (SSSI) and we are currently trying to find out from Natural England if a habitat management plan could be put together for the SSSI that included variation in the water level of the main reservoir (especially in summer when water would be required for the canal).
This image (courtesy National Library of Scotland) shows the 1890 map of the original reservoir overlaid on the aerial imageof the reservoir today.
Ken Oliver
@canalken
