Sequential report

[nod]

We had a flood report done as part of the purchase Moderate risk River 2.8 km away 

I was quite suprised to get a call from the Architect telling me planners are now requesting a sequential report 

Before they will grant full planning 

I spoke to a survey company The lady explained that the report will identify more suitable sites Zone 1 Rather than 2 which we are in Still no wiser 

 

Has anyone any experience of this and possibly a rough idea of cost 

[jamieled]

I do this sort of stuff but in Scotland where it's a bit different. Don't have a good handle on costs in England. Looking at the guidance it might be possible to work at it yourself if you have the inclination. 

This will give you some good background on sequential assessment (follow the links) if you haven't already found it:

https://www.gov.uk/guidance/flood-risk-assessment-in-flood-zones-2-and-3

 

[nod]

1 hour ago, jamieled said:

I do this sort of stuff but in Scotland where it's a bit different. Don't have a good handle on costs in England. Looking at the guidance it might be possible to work at it yourself if you have the inclination. 

This will give you some good background on sequential assessment (follow the links) if you haven't already found it:

https://www.gov.uk/guidance/flood-risk-assessment-in-flood-zones-2-and-3

 

Thank you Jamie 

Great help 

[saveasteading]

3 hours ago, nod said:

Anyone any experience of this

Me.

Have done this in England twice and also handled  existing reports for a bigger project.

 

The fundamental point is that you should not build in such way as will increase flooding generally, or have damage to your own building in flood unless there is a very good reason to build exactly there.

So the test is if you have tried other places, and found there are none suitable,  and why your project is so important that others are put at increased risk.

 

It is one of those things that follows a logical pattern. Brief, issue, background, proposal. etc., and you can probably find someone else's on the local planning portal. that will have the advantage of having similar issues. 

Then you can contact these consultants or be inspired yourself, or see why to give up.

 

Mine took about 12 pages, arguing why this client was a huge asset to the area but had to expand next to the very big river  or move away.

Plus the facts of the project, the effect flood would have, and designs that avoided damage to the building in a metre of river.

He had 'looked at the other sites but they are all in other towns'  blah blah.

Our client had to sign a form that he realised that his factory might flood, and no claims would be made. He had a plan if a flood was forecast but not for accidents.

 

 

Another by the sea for an infill. This was very difficult to justify, and wasn't tested as the client pulled out.

 

Meanwhile I have seen reports maybe 50 pages long. Whether or not this was necessary I can't say, but the planner seemed impressed by the thickness of it.

 

It is unlikely to be a diy.

 

Cost will depend on the attitude of the planners (is it box ticking or do they really need convincing?). £3k to £20k for a single small site?

 

that might not be the end. One client had to get the flood modelled by computer to show what effect the river would have.  Add another £20k for a big, very specialist consultant.

 

In summary, I suggest you first discuss with your Architect if there are clues from the planners about the seriousness level of this, and local precedents..

Then find a local Civil Engineering consultant  who has done this successfully and have a preliminary discussion before committing to them or to proceeding with your project.

[nod]

Thanks for that 

Planning in principle was originally granted I can’t understand why this wasn’t raised then 

Also another 50 metres and we would be in zone 1 

We are a long way from any watercourses 

Unless you count a pond across the road in zone 1

[Ferdinand]

12 hours ago, nod said:

We had a flood report done as part of the purchase Moderate risk River 2.8 km away 

I was quite suprised to get a call from the Architect telling me planners are now requesting a sequential report 

Before they will grant full planning 

I spoke to a survey company The lady explained that the report will identify more suitable sites Zone 1 Rather than 2 which we are in Still no wiser 

 

Has anyone any experience of this and possibly a rough idea of cost 

 

Does that mean that they want you to identify different places to build?

 

@saveasteading it sounds from above as though the increased risk is de minimus. IIRC isn't @nod doing 2 houses?

 

Like the traffic reports requested where the underlying assumption seems to be that adding 5 or 6 traffic movements per day to a road that has 200-300 already will cause the sky to fall in.

 

How would I play it? Not sure. I think I would perhaps consider relying on the argument that this ship has now sailed, and that its not something for detailed stage (having looked at Appeal precedents first).

[Mr Punter]

I have seen these where they just say that no other sites are under the ownership of the applicant and so were not considered.

 

You probably have to do this as part of a flood risk assessment, where you submit plans and EA flood map information.  There are lots of firms who will do the report.  Get lots of quotes!

[saveasteading]

4 hours ago, nod said:

Also another 50 metres and we would be in zone 1 

We are a long way from any watercourses 

Unfortunately you are in Zone 2 and 'near to zone 1' makes no difference unless you can show that it is a matter of millimetres height difference.

This flow chart is helpful. 

It is a matter of showing the planners that your proposal is not a concern to the community or your own building.

I hope your architect has covered the second part by raising  your floors above the zone 2 flood level.

 

As the table above, you do not need the Exception test.

Their job to question it, and rightly so, and is your task to prove safety.

This should not be onerous, so get expert help. The priority is a report that does the job, but I would probably charge you £2,000 with some caveats about level of detail, and extras for further detail if required.

[Ferdinand]

Is it an acceptable strategy to raise the height of the house a foot or two to make it at the same level as Zone 1 50m away, if it is that close?

[nod]

It’s a bit annoying really 

It seams like the same old nonsense to folk out a couple of grand on another meaningless survey 

The laughable thing is that we looked at a plot about a mile up the road Further into zone 2 Right next to the canal and they have just received full planning 

 

[Mr Punter]

I just met with someone and they have spent £250k on a planning application for 50 dwellings.

[Mr Punter]

I got planning on a site in zone 3a.  It was town centre and needed redeveloping.  If it was out of town we probably would have got nowhere.  Zone 2 should be fine, just a few extra fees.

[saveasteading]

4 hours ago, Ferdinand said:

raise the height of the house a foot or two

That should satisfy the requirement that your house is not flooded itself. It still remains to show that your house is not increasing risk elsewhere, which is presumably the case.

 

49 minutes ago, nod said:

zone 2 Right next to the canal and they have just received full planning 

You can quote that as precedent, but it should be easy enough to show why your building causes no change in flood risk 

I suggest you look at the planning app for the canal-side house and see if they included the flood risk assessment with their app.

 

This is not simply yet another report as an onus. The risk of flooding is very serious and increased by new development. Yours appears simpler each time you tell us more, so should not be expensive. The architect should perhaps have spotted the matter earlier and dealt with it in the original app. Maybe they could now do a simple statement that will satisfy the planners.

[Ferdinand]

17 hours ago, saveasteading said:

That should satisfy the requirement that your house is not flooded itself. It still remains to show that your house is not increasing risk elsewhere, which is presumably the case.

 

In relatively the middle of nowhere I do not see how increasing the height of say 0.01 Ha by 45cm increases the chances of flooding elsewhere. 

[jamieled]

1 hour ago, Ferdinand said:

 

In relatively the middle of nowhere I do not see how increasing the height of say 0.01 Ha by 45cm increases the chances of flooding elsewhere. 

It won't much. But there's increasing concern amongst regulators about cumulative effect from multiple small developments. It also removes the need to identify a threshold beyond which impact is likely  - it's more straightforward to apply it to all development.

On a related note we also know that permitted development has, in some circumstances, made a significant change to flood risk.

[saveasteading]

3 hours ago, Ferdinand said:

In relatively the middle of nowhere I do not see how increasing the height of say 0.01 Ha by 45cm increases the chances of flooding elsewhere. 

Exactly so. And the report simply has to make this clear.

A small house in the middle of a flood plain is not a problem.

 

Whereas as an infill in a row of housing in an overflowing river, it might block the only way for the flow to escape.