Device For Measuring Height Above Sea Level

[CluckyChick]

What is the easiest way to measure height above mean sea level? Is there a gadget I can get to do this? I need an accuracy to 0.1m, which is more accurate than on the things you get for mountain bikes etc to show altitude. Guess I need whatever surveyors use. Advice or suggested search terms would be much appreciated thanks.

[KARL]

An accuracy of 10cm is very exacting and I very much doubt that as an ordinary individual you can affordably acquire any equipment that is reliably capable of providing what you want.

[New Judge]

There are a number of apps you can get to measure height above sea level but I doubt ant=y of them or accurate to +/- 10cm.

Just out of interest, why do you need such accuracy?

[4candles]

Maybe ask G&J Surveys what they use?
http://mappingmountains.blogspot.com/2013/12/g-surveys-introduction.html

[CluckyChick]

The accuracy is what the council are asking for as part of a flood risk assessment in support of a planning application for some wooden stables.

[New Judge]

Ah the council. Definite overkill. They thrive on it.

[Zacs-Master]

Did you know you can get a food risk assessment plan specifically for planning apps from the NRA website?

[Zacs-Master]

Not NRA. Environment agency. You’ll need a specialist company to do a risk assessment if the map confirms you’re in a risk zone
http://apps.environment-agency.gov.uk/wiyby/37837.aspx

[CluckyChick]

Thanks, yes it is a flood risk zone. Specialist survey just seems like overkill in this case though.

[Zacs-Master]

Problem is, they may not validate your application without one.

[TonyVent1959]

Do you know if and when your property or area was last or has ever been flooded?

[HansUrbancka]

Forgive my attempt at humour, but the attitude of your Council doesn't make horse sense.

In all seriousness, I would have thought that the local Council should already be in possession of the information they have requested from you.

As NJ has said, "Ah the council. Definite overkill. They thrive on it."

Ask the Council how you could obtain such information if they haven't already got it.

Hans

[TonyVent1959]

might be a bit of a fath but why not try an ordnance survey map which will be accuratehttps://www.ordnancesurvey.co.uk/blog/2011/08/how-do-you-measure-sea-level/
and maybe ask the planners what tide level do they want established i.e. high / low / or mean and at what time of year and what moon phase, if you want to create a conversation in the planning dept ? Do I like bureaucratic council depts - you decide lol

[HansUrbancka]

Incidentally, the link given at 22.25 by ZM is worthwhile exploring because the site stipulates..."Our aim is to make as much of our data as possible available free of charge".

Best wishes ...Hans.

[Zacs-Master]

Arguing with the council about sea levels will only serve to delay the application. They will want the land levels above Ordnance Datum. They may also want Hydraulic modelling info which you’ll need a specialist for.
Some more info here:
http://repo.floodalliance.net/jspui/bitstream/44111/1196/1/GUIDANCE%20ON%20PRODUCING%20A%20SIMPLE%20FLOOD%20RISK%20ASSESSMENT%20%28FRA%29.pdf

[KARL]

Almost regardless of the facts regarding the ground, elevations, location of watercourses, 100 year storm data, etc., etc. you are likely to be up against two obstacles that basically have nothing to do with flooding of your land. These are a) that laws and regulations, working methods of authorities and public institutions, etc. are at least 50% designed to build up pressure for job creation - you are forced to turn to a collection of companies/"specialists" to get "acceptable" opinions/certificates and pay them for it. The other thing is b) the inclination of individuals and groups within the "system" will always, and actually entirely understandably, be to ensure they cannot later be criticised for having missed something, been careless, not followed procedure, etc., etc. - this is the driver for what NJ rightly refers to as overkill. There is a strong tendency to pad the insulation out with "findings", "advice", etc. from third parties whenever asked for. In reality, overkill is a defence mechanism against the public's modern penchant for finger pointing and appetite, via the press, for watching the humiliation of fellow humans.

That said, flooding is a very serious problem in England, and increasing with the years. In hindsight, many of the areas recently affected have been inadvisedly planned.

[New Judge]

Indeed. I know of a housing development in Dorset built on the flood plain of the River Brit, just before it enters the sea at West Bay. Regularly floods. I wonder if a "risk assessment" (to +/- 10cm) was done there. In fact there was no need as anybody could have told them that the area floods once or twice every year, regular as clockwork.

[TonyVent1959]

I appreciate its again not to the degree of accuracy you require but google earth will give you height to within 1m. you could try a few points around the proposed building and take an average.
Also check with council that they have not got decimal point in the wrong place/

[smartypants10101]

has the area flooded before? if so what date did it happen and look at the rainfall for that time, if the area has never flooded before i cant see it been much of a risk

[waterboatman]

An Ordnance Survey map of the area will give the information you need. They are to Military specifications, i.e. very accurate.