03-03-2016: The D to R of water habitats

Come in and join the gang

What do these two images have in common? They are both sections of water habitats associated with the Hogsmill which we are trying to restore.

Please note the following small print: This may be my busiest week for posts! This post is longer then usual due to Hogsmill Forum information. There may also be another post coming soon (this week or next) with the photo competition winners! After which posting frequencies should go back to normal :)

D for Ditch

On Saturday 20th Feb, we ran our annual ditch day at Tolworth Court with The Conservation Volunteers (TCV).

A quick toolbox talk and then we all got stuck in

The aim of the day is to get really muddy and have a fantastic workout while improving the habitat for both wildlife and people but this requires striking a balance between having a dry ditch to aid water drainage and a wet ditch which can support more wildlife. These pages from Buglife and Greatfen.org are good sources of information.

At Tolworth we have to keep the site dry as the primary function of the ditches are to drain the sports pitches.

But we are improving the ditches for wildlife by modifying the profiles and undertaking mirco habitat management by insuring that we are not removing areas where ant’s nests have been developing.

An example of a before and after shot

Come Spring the grasses and other herbs will have a better chance of colonising the ditch as we have been removing the bramble that was starting to take over in areas. 

The modifications should make it easier for wildlife access, as well as improved use as a wildlife corridor up and down the site. 

Female frog hopping out of the ditch making her way to a habitat pile

On Saturday the team worked hard through sunshine and rain, scalloping the edges on one side of the ditch as we worked along it. 

We got a lot done on this new section of ditch and will continue to work on it later this year.

We are always on the lookout for more volunteers to help, if you want to sign up now for the winter 2016/2017 ditch day which may occur in November 2016/Jan 2017 email me today (biodiversity@kingston.ac.uk), and I can email you dates and times closer to the event to see if you are still free.

R for River

While I knew that the Hogsmill River had been the inspiration for the Ophelia painting as pictured above, what hadn't sunk into my mind was that the Hogsmill River is a Chalk Stream – this is a rare habitat in the UK. This infographic is a nice summary of all of the problems facing our rivers.

It’s now very rare to see the pristine areas of chalk stream on the Hogsmill, apart from a few areas near the start of the catchment, by the time it gets to Kingston, the river is very much degraded due to pressures and pollutants including sediments entering the river – largely from the urban areas located on the Hogsmill.

It may not be possible to get the whole water course back to full ecological status, as it’s been said that that would require urban areas such as Kingston to be demolished (not happening any time soon to my knowledge!).

But despite having highly urban areas on the river, we have the potential to get the river back to having a status of good ecological potential.

Joe chairs the second forum at the Zoo. 

The Hogsmill Forum is an opportunity for different groups and projects working to improve the river to feed back to one another and act as a vehicle to identify opportunities for change and possible solutions to common problems on the river.

We had several speakers this year. I hope to add links to their talks to this blog as they become available, until then I have tried to add a brief summary below each of the talk titles to give you a flavour of the day.

• Incident reporting – Stephanie Ilsley (Environment Agency (EA))

Steph talked about the process that the EA undertake to prioritise pollution reports to their hotline (0800 80 70 60) and how they then deal with the incidents.

As with any such reporting, accurate data as well as quick reporting is key. THE key messages from her talk are:

1. Incident reporting has increased in the last three years. But it may be a reflection of better reporting rather than more incidents. 

2. Pollutants are mainly sewage which is expected given the misconnection issue we have in the UK 

3. Reporting is VITAL – incidents are often intermittent, so if you see something please report it rather than assume that someone else has, as the issue may be so infrequent that no one else knows about it!

• River Monitoring Initiative (RMI) update – Joe Pecorelli (Zoological Society of London (ZSL))

Just in case you've not read any of my previous posts about the RMI, this post tells you all about this initiative. 

The Hogsmill RMI sites

There are 5 monitoring sites on the Hogsmill spread out through its catchment (KU is number 5). The top most site – Green Lanes has a fairly regular survey result without any breaches in the Trigger level (a breach is bad). The Ewell Storm Tanks had a major drop in score in August 2015 which needs to be investigated. Sites 3 and 4 suffer chronic pollution; as such they have regular breaches in the trigger level, which is an issue as it means that major incidents are not being picked up.

The University site had a higher than average score in 2015, which may be a reflection of the more diverse habitats that we have here (including ones we created). However it should be noted that we have had two months with two breaches in 2016 which will need to be investigated further. 

• Hogsmill Storm Tanks: What we know so far – Polly Bryant (South East Rivers Trust (SERT))

Polly talked about their investigation of the storm tanks in the Hogsmill. These two storm tanks are inherited infrastructure, in that they were not built by Thames Water, and the amount they are discharging is not known! This abstract provides a good summary on how storm tanks work. 

SERT have been working with the EA and undertaking experiments to establish what the capacity of the tanks are so that they can estimate the number of times the tanks have discharged raw sewage into the river. 

The study forms part of the evidence needed by Thames Water to make the financial case for working on this system to fix the problem. 

• Water quality continuous monitoring Epsom and Ewell Storm Tanks - 2015 – Kathy Friend (EA)

Kathy talked about the new water testing which is being conducted up and down stream of the storm water tanks to gain a better idea of the effect these have on the water quality. The testing using probes is still a little glitchy, but it has shown us that the water quality by the storm tank near the Longmead Road area, is more polluted then the Hogsmill stretch (which still has poor water quality) by King George V Recreation Ground which contains the other storm tank. The poorer water quality may be due to lots of problems with misconnections in the area. 

• Progress report on the remediation of polluting surface water outfalls in the catchment – Ruta Akelyte (Thames Water (TW))

Ruta gave us an update on the action they were taking in areas where they had identified misconnections and managed to trace them back through thousands of homes, to those that were misconnected. 

What was interesting to learn, was that TW have no legal authority to get the home owners to fix the issue. They have to involve another authority who can able to serve enforcement notices, once served, it can take time to ensure that the fixes that have taken place, are being effective and that further issues have not developed. This also explains why the process can often be long and involved. 

• An overview of how the invertebrates of the Hogsmill have changed over time- Sue Skipp (EA)

Sue’s talk showed how the EA’s testing of river invertebrates (conducted at a more in-depth level then the RMI testing) corresponded to the water quality in the system.

With the two charts below indicating that while the situation in both test sites appear to be improving slowly, they both indicate a poor and moderate water quality in the Hogsmill at these test sites. 

• Lessons learnt from the Upper Wandle : How good can an urban chalk stream get? David Webb (EA)

Finally David walked about eh potential future for the Hogsmill, and what were the possibility of having good ecological potential. He explained that the likelihood of getting a higher level of water quality then this would be very unlikely given the historical and current setting of the river, going through highly urbanised areas such as Kingston. 

Key messages

A quick shot of the 2016 Forum participants

After the forum (and before if you get there too early) there was a chance to have a quick walk around the zoo. I thought I’d share a couple of shots from the day, including what I felt was an effective communication display of the issue of turtle conservation in Asia where they are eaten.