Henllys LNR Car Park Sustainable Drainage Solution Update

 Its very sad, but not uncommon to see the vast amounts of flooding across rural and urban areas and the devastation this brings. Locally, there are loads of blocked drains and copious damage to roads. 

Our own mini-SuDS project funded by Keep Wales Tiday was finisheed a couple of years ago and is reported in the previous blog entry. What we were seeing was the car park itself was getting flooded as the drains were blocked by silt. 

These 2 pictures were a regular occurance after heavy rains.

The silt was coming from the grassy hill adjacent to the car park. As people were walking up or down the bank, desirelines would muddying up and vegetation being trampled. The rain then washed down these desirelines taking silt downhill, emptying into the car park and blocking the drains. Our solution to this was very simple in that we roped off some of the desirelines, planted some shrubby vegetation on here, dug a few little trenches which fed into small shallow silt traps and most importantly at the botttom of the hill, we built a retaining wall of oak sleepers, backfilled these with soil and overlaid these with our favourite native wildflower turf

The retaining wall with wildflwoer turf on top. The main access path to the right remains.

 (htps://twitter.com/HenllysLNR/status/1314828591805411328). We've recorded on our Facebook page and Twitter how well these have worked (https://twitter.com/HenllysLNR/status/1397112031971577856 https://twitter.com/HenllysLNR/status/1335321551051366400). 

Trench and mini-silt trap

Silt settles into wildflower turf and clean water drains through the gaps in the oak sleepers as well as over the top of the turf.

Since these were installed just over 2 years ago, there have been many storms bringing heavy rain to South Wales as well as many other heavy rainfalls. We have not had any occurances of the car park flooding in that time. The wildflower turf has been really succesful too bringing a wide variety of wildflowers which have been totally under our own management which has meant it hasn't been cut back too early i.e. while it is still in flower. Its been a haven for insects and we even recorded seen in the vegetation in December. Another great success for us at no cost to the Local Authority.

Local Places For Nature: Henllys LNR Car Park SuDS Project

The car park off Birch Grove which is the principal entrance for Henllys Local Nature Reserve has undergone significant biodiversity improvements thank to our Group's efforts over the years. This started with the Natural Buzz Project:

http://friendsofhenllyslnr.blogspot.com/2016/10/natural-buzz-natural-expansion-of-our.html

http://friendsofhenllyslnr.blogspot.com/2016/10/natural-buzz-ground-prep-for-bulb.html

http://friendsofhenllyslnr.blogspot.com/2016/10/natural-buzz-winter-flowering-area-and.html 

http://friendsofhenllyslnr.blogspot.com/2016/10/natural-buzz-bulb-delivery.html

http://friendsofhenllyslnr.blogspot.com/2016/10/natural-buzz-planting-with-henllys-ciw.html

http://friendsofhenllyslnr.blogspot.com/2016/10/natural-buzz-marking-out-areas.html

http://friendsofhenllyslnr.blogspot.com/2016/10/27th-october-2016-today-wildflowers2be.html

http://friendsofhenllyslnr.blogspot.com/2016/10/natural-buzz-wildflower-turf-laying.html

Updates on Twitter in reverse chronological order here: https://twitter.com/search?q=%40henllyslnr%20%23naturalbuzz&src=typed_query&f=live.

The uphill side of the car park hasn't had much improvement done to it, but has other issues. There are several shortcuts (desirelines) which have been used over the years to get down from the field into the car park. As we know, where people tread on a slope, it is only a matter of time until rainfall and the follows. This has happened several times over the years and especially during heavy downpours, the soil is stripped and washes down the bank into the car park and the silt is deposited along our watercourses and inevitably blocks the drains and floods the car park. This leaves a green slippery and smelly mess behind. The council eventually unblocks these drains, but it is a really low priority drain. What we needed was a SuDS project to address that. 

Luckily, Keep Wales Tidy announced a project in 2020 called Local Places for Nature, funded by Welsh Government (like our Natural Buzz project). This has small Starter Packages and larger Development Packages (https://www.keepwalestidy.cymru/pages/category/nature Grants still available July and Aug 2020). Each are divided into 3 parts with one of the larger packages, a SuDS project (https://www.keepwalestidy.cymru/nature-development-suds). We quickly applied and were successful in the first round of applications. We obviously needed a plan and permission from TCBC. 

We posted all of this information on our Facebook page and created a video to explain it all:

As I write this, have also completed the first part of this project, which is the retaining oak sleeper wall, which will act to collect all of the runoff from the slope. 

Brian and I worked on a Friday to built a proof of principal start to the wall using oak sleepers we had from another project. We also prepared all of the rest of the ground for the main delivery which was planned for a fortnight later. However, we had a call the following Wednesday from Travis Perkins saying all of the materials were on site at 8.30 am and were waiting for us. Well I had to pack up work for the day and worked from 8.30 am to 8.15pm to make the whole site was secure.Brian and I did this with help from my neighbour Yvette (early morning shift) and my wife Sally (late shift). All of this was done with 2 m social distancing in mind and only people from 2 households at any one time. With 2 more people we would have finished this hours earlier, but that's a pandemic for you. Ideally, we'd have built the whole wall first and then got the bags of soil delivered later where we'd have just cut the bags allowing the soil to fall where we needed it. As it happens we just had to cut the bags and do more shovelling instead. This is still much better than wheelbarrowing it. 

Anyway, I created this follow up video to help any other Groups who are doing this kind of work. One of the big problems is that many of the sleepers were not very good quality and were very warped. This also slowed us down a lot. Hopefully this video will help others:

The next stage will be installing the 2 x SuDS planters which will be very interesting as they weigh 130 kg each. Again, what we learn will help the other 21 projects. We'll be doing this in the 1st week of August and then we'll lay the wildflower turf in October time if it is cool enough. 

Henllys LNR CoVID-19 Home Wildflower Project

March 2020

Due to the CoVID-19 outbreak, several projects planned for Henllys LNR this spring and summer have had to be abandoned or postponed. However, the Henllys COVID-19 support Group gave me a chance to think about what we could do together even though we are all at home apart from each other.  from From this, the Henllys LNR Home Wildflower project was born. So far 45 different families across the area have come together to take part in transforming part of their gardens into native wildflower havens.

Map showing rough distribution of Households taking part

https://drive.google.com/open?id=19ihKs7BVbuyiE4zAyMeYB9QUi39qla52&usp=sharingI created a downloadable introductory document which helps local residents to understand what we are trying to do and contains all the recording sheets and guidance on what photos to take.
 
With help from Sammy Gawler, a local teacher, we have created a wildflower detectives series of activities to entertain and educate children at home. This work will also provide data which will be analysed by local children.

Finally, I created a "how to" document, which details how residents sow their native wildflower seeds. I also created a short practical demonstration on the principles of transforming areas of lawn into a wildflower meadow.

Links to downloads:
1. Introduction.
2. Wildflower Seed Detectives
3. How to prepare grounds and sow wildflower seeds
4. YouTube video of a practical demonstration of wildflower seed sowing

How to sow a wildflower area; an applied practical demonstration

Wildflower Seed Detectives

Oct 2018 - grass patch being dug over between my neighbour and our houses

Post-seeding and being tamped down

Same strip in June 2019

Same strip in June 2019 from above

Chamomile shark moth caterpillar (same strip) - July 2019.

Same wildflower strip (July 2019) 

Hoverfly on corncockle (same strip July 2019)

  You can view some of the wildflower areas across the project on the Facebook page here: https://www.facebook.com/groups/HenllysHomeWildflowerGroup

We’ve stopped updating on here, please see our Facebook Page

Dear all,

I’m afraid we’ve stopped updating the blog in favour of a more local targeted social media platform using Facebook. https://www.facebook.com/groups/FriendsofHenllysLNR/ To join, you just need to answer the 3 questions so we can verify your request.

Cheers,

Chris

Rain, pave, wash away, leaves have gone and blocked the drain

It can't have escaped your notice that we've had some pretty bad weather recently with the fallout of two storms, bringing heavy wind and prolonged rainfall and all this water has to go somewhere. In the face of an ever increasing drive to build new houses and a growing trend to pave over front gardens for extra car space (and less maintenance) less water is soaking into the ground and is taken away through drains. These drains enter into man-made channels:

Where these channels end, the water enters old streams and they simply can't cope with the increased volumes of water often resulting in large erosion issues. This is one of the reasons why we have put so much effort into protecting stream banks with our wooden bundles made from harvested willow from the LNR. These fill up with silt and work brilliantly.

These bundles were done several years ago and saved a huge erosion point from getting worse.

A big problem starts to happen with massive downpours, which is compounded by the heavy winds breaking off lager branches all accelerating natural autumnal leaf fall. Larger branches and twigs get washed and trapped against the metal grills of man made culverts, which make a kind of nest which gets lined with all the leaves, which cloggs up the flow of water. When this happens, the water levels back up , rise and even greater erosion and flooding occurs.

This was back in November 2014

Luckily, there is a department within Torfaen Council who have responsibility for drainage. However, it isn't just culverts they look after, it is also all the drains on all the roads in the county. It doesn't take too many autumnal leaves to block these drains, resulting in localised flooding. It is impossible for these teams to be everywhere all of the time and in fact a dog walker told me this evening that they were out cleaning the culverts on the LNR only last week. To help out and from time to time, we get out our muck rakes as volunteers and help to clear out the culverts which pass through Henllys LNR. Today was one of those days, in the pouring rain.

Before

After

Before

After

At the minute, the whole LNR is saturated and the ponds are full. There is surface water everywhere and the streams are all raging. The desire lines are all marshy (apart from on our Gwent High Sheriff's Community Fund path) and the water is just finding its own way down to the lowest point. I came across this really interesting rutted stream where the water just flows its way down off the main meadow and then disappears down a hole. This looks cool, but I don't know if it is washing the bank away creating a potential hazard. Only time will tell. This little stream only came about as a result of LNR users walking along a desire line on the main meadow and the water will always take the easiest route.

As a final word of caution, if you are visiting the LNR, bring your wellies (and a buoyancy aid).