Jump to content
Calibre_Consultancy

Calculating RPAs of extensive hedgerows

Recommended Posts

Hi all,

 

Just a quick query with regards to a clients wanting hedgerow RPAs. If your TOPO has the hedgerow extents plotted and in some cases the hedgerows centre lines, do you just get yourself an average DBH for the whole hedgerow and measure the RPA from the centre line of the hedgerows?

 

I ask because obviously the width of the hedges will in many cases be much further out from the stems than the RPA radius and also just because you have a centre line, this doesn't represent where the hedgerows stems actually lie and therefore the RPA would be inaccurate in places because the stems are all over the place.

 

Or do people just place the RPA lines in line with the extents of the hedge itself?

 

If anyone can answer this for me it would be much appreciated!

Share this post


Link to post
Share on other sites

Just a thought out loud here, as most development usually takes place on one side of the hedgerow only, and hence the other side is undisturbed, that would hopefully mean either the crown spread or half-height scenario would suffice...appen.

 

That said not as a practitioner but a theorist :confused1:

 

cheers..

Paul

Share this post


Link to post
Share on other sites

Ya.. In this case the hedgerows are in the middle of the plot, they are to be retained and the proposal designed around them.... and the retained trees obviously.

 

Is it me or is this not covered somewhere in 5837 ..... I couldn't find it in there.

 

Thanks

Edited by Calibre_Consultancy

Share this post


Link to post
Share on other sites
Ya.. In this case the hedgerows are in the middle of the plot, they are to be retained and the proposal designed around them.... and the retained trees obviously.

 

Is it me or is this not covered somewhere in 5837 ..... I couldn't find it in there.

 

Thanks

 

Sorry, shudda checked there first see p.7 sect. 4.4.2.7&.8

 

Paul

Share this post


Link to post
Share on other sites

Yes thanks I had already read that section and have recorded the dimensions as per the regs but then it says collect this info to ensure that the constraints can be fully assessed. No specific mention of RPA calculation which is itself a constraint ???

 

Im just assuming that the extents of the hedge is more of a consideration as a constraint than the RPA calculated from DBH

Edited by Calibre_Consultancy

Share this post


Link to post
Share on other sites

There's only one issue here, and that is how much of the roots and soil need to remain undisturbed to ensure the ongoing vitality of the trees. RPA is just a first guess, and a relatively easy way out. If the simple RPA method is not appropriate, for whatever reason, it's up to you to satisfy the Council that any encroachment into the rooting area (not the RPA) will not damage the survival of any of the trees.

 

The centre line or skew I expect is an irrelevance. Forget the RPA cop-out and try and justify a linear extent of root protection. That's my view anyway.

Share this post


Link to post
Share on other sites

Thank you for your help both.

 

We are at very early stages at the moment. The client doesn't even have a draft design ready yet but as things go I would expect that they would be looking to incur on the vegetation.

 

Thanks again

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Featured Adverts

About

Arbtalk.co.uk is a hub for the arboriculture industry in the UK.  
If you're just starting out and you need business, equipment, tech or training support you're in the right place.  If you've done it, made it, got a van load of oily t-shirts and have decided to give something back by sharing your knowledge or wisdom,  then you're welcome too.
If you would like to contribute to making this industry more effective and safe then welcome.
Just like a living tree, it'll always be a work in progress.
Please have a look around, sign up, share and contribute the best you have.

See you inside.

The Arbtalk Team

Follow us

×

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.