Having passed through bustling Bourton on the Water and Birdland the river emerges into open countryside again.
Here she passes the infamous ''Land Treatment Area'' which featured with us in BBC Countryfile last year.
Someone has had our Youtube Channel clip of that taken down and we are working on getting it back.
This is the business end of where a long pipe diverts untreated sewage from the pipe heading from Bourton to the sewage works, set outside town at Little Rissington on the River Dikler. The diversion uses a weir system, so when too much flow is incoming, the excess fluids go over the weir and head along a pipe to a field which was once a filter bed of rushes. It is now a series of ditches covered in shrubs and nettles and when they fill up, the sewage goes via another pipe to the river. This is the pipe.
This is supposed to happen only in periods of heavy rain and high river flows but we have been told that the sewer is leaking and it allows infiltration from groundwater so that in April last year, for example, data provided to WASP and Countryfile showed that it was discharging to the land area at one stage for 7 days, 24 hours a day.
A lot of the condoms, toilet paper and sanitary towels were geting caught by the nettles and plants and then some brave soul had the job of ''litter picking''. WASP has been told that some of these things make it to the river and that is unsightly, but the raw sewage, chemicals hormones, antibiotics and whatever else is in that toxic mix, are what we are concerned about, as well as contaminating the soil and groundwater here.
All this just because Thames Water has not fixed its sewer pipes and the Environment Agency has let them carry on like this for years. The cost benefit calculations very often seem to regard our environment as not worth the cost to the industry.
On the plus side, since the TV programme Thames Water has undertaken to line these pipes and fix the problem and avoid the scene below, we hope.
We are pretty sure that a combination of favourable weather and a hearty effort by Thames Water has avoided some such spills this year, and long may that continue, but in a more sustainable way.
Fortunately, the regulator, Ofwat has told us that Thames Water does not have to be restricted from improvement by the often very basic standards required of it by the Environment Agency (Defra) if those are not delivering decent standards to the community. We have often heard the message; ''We would like to do more but the Environment Agency don't ask us to, so we can't''.
Equally fortunately there seem to be some open minds and a lot of willing people in Thames Water who are ambitious about improving our environment and it is pressure from ordinary people that will help them prevail over the profit chasers.
This is the lovely little river that should be spared that toxic dose.
On she goes until she meets the River Dikler coming in from Little Rissington where it has just passed the Bourton Sewage Treatment works, where it picks up the effluent and something more which we will bring in to the next blog. For now we will just show some pictures of how the nature of the Windrush changes.
From this stream, with the lovely golden gravel bed she meets the Dikler you can see to the right of the photo.
Here the two merge.
By the way, we have video of the river with a golden gravel bed like this at Witney - but that was in 1998
The two rivers merge and this is what we saw on that sunny day.
And a different future beckons. The phosphate readings we have had on the Windrush to this point have been very low so that they often showed zero on our meter.
The merged rivers have given us phosphate readings of 0.27 mg/l and 0.2 mg/l so far in this area, where 0.1 mg/l is regarded as highly polluted (Earthwatch Water Blitz). We are developing our citizen science capabilities and will be making our results public and accessible.
I walked this section with Vaughan Lewis who is an independent Environmental Consultant and it was reassuring to know that he also saw the changes in the Windrush as it met the Dikler as dramatic and not in a good way.
Our eyes told us that the colour of the river is different here as the rivers join. There was also a dark coating of diatoms and sediment of the gravel. To do anything more with that information we need a turbidity (cloudiness) meter to take the doubt away and to have some proper references, so we are going to have to buy one. Maybe with some discount from a helpful supplier, as these can be expensive.
We have been relying on a small group of local donors and our own funding but now have a PayPal DONATE button on our website so we hope to be able to do a lot more with our volunteer team. If you would like to donate, we have HMRC Gift Aid authority and we are a Charitable Trust. None of us take any wages or even expenses so your donations will go a long way to helping get the Windrush back in a healthy state.
The Windrush grey very much in evidence but is it really the Dikler grey?
This little stream left the Windrush before the Dikler joined and runs alongside the main river you saw in the previous photo. Ok it is shallow but are you seeing any grey clodiness in the water or dark coating on the gravel bed? Food for thought and further investigation.
Next time we backtrack the Dikler to see the Bourton sewage works and tell you a tale or two about what goes on there - and a bit of deja vu type history.
If you are enjoying the blog, or at least finding it interesting, please don't forget the donate button on the website home page.