[OSGeo Africa] Municipal boundary demarcation

Wed Jul 20 07:29:14 PDT 2016

All,

I agree that the scale of published maps is not very accurate, that’s why they have it downloadable in shapefiles. Admittedly not captured with great precision with respect to the cadaster and other features.

The Act says that when determining the boundaries, the board must take into account a whole long list of factors including the “existing and proposed functional boundaries….” (presumably things like cadastral boundaries amongst others) – including the public consultation process.

They do not publish their weightings to each criteria that they must assess before arriving at the final shapefile. It would be very wrong to simply adjust it to the cadastral line when one does not know the weighting they applied to each of the factors they had to consider including public input. Perhaps in consultation with a municipality, the municipality could have told them they wanted to put a future road along that boundary and so the demarcation board left that “buffer”. Perhaps in other cases the demarcation board has digitized a stream/river directly off imagery and that river has moved with respect to the cadastral boundary. 

Even in cases where it’s clear as daylight that the demarcation data and cadastral data should align, if could well be that in rural areas, they may have followed ground information such as the induna areas of the tribal authority – which by the way, in most cases does not follow cadastral boundaries anyway. I have picked up on a few occasions, on housing jobs, this difference and its quite rational as it’s based on the peoples loyalty to different indunas and chiefs.

The word “cadastral” does not even appear in the act – surely if they intended it to follow such, they would simply just say so. Rather they use “functional boundaries” – which actually makes sense as it allows consideration of a whole host of other factors in their determination.

It would be wrong to adjust any demarcation data, without evaluating the same criteria and information that was on hand to determine the limits in the first place – to do so would be in violation of the act as the act lays down all the considerations to take into account.

Regards

Peter

From: David Barkhuisen [mailto:dave at kirchhoffsurveyors.co.za] 
Sent: Wednesday, July 20, 2016 2:55 PM
To: newmarch at land-surveyors.com; Africa local chapter discussions <africa at lists.osgeo.org>
Subject: Re: [OSGeo Africa] Municipal boundary demarcation

Hi 

The gazette maps do not describe the area in an accurate manner such as the way a survey diagram or mining/prospecting diagram does with a diagram and accurate coordinate list. The gazette maps certainly don't involve much accuracy seeing as the Ethekwini gazette map in the link below is not drawn to scale.

http://www.demarcation.org.za/index.php/downloads/boundary-data/kwazulu-natal-4/eth-1/detailed-ward-maps-156/2994-eth-ward-1/file

Regards

David

On 20/07/2016 13:47, Peter Newmarch wrote:

Chris,

The demarcation data is fixed. Its Gazetted as a map and not by cadastral boundaries or features. The land might for rating purposes fall in JHB, but for approvel purposes (SPLUMA) wherever the development falls spatially in terms of the municipal demarcation data – then that is the municipality.

I recently saw a case where a parent property was in Municpality A, but the new sub was Municpality B – because of the mismatch between the data.

Municipal data is determined by people numbers, while the intention might be to follow certain cadastral lines, its unfortunately not Gazetted that way and so leaves no room for any interpretation whatsoever – its fixed in absolute terms.

I know of two cases where very large farms are split down the middle because of municipal demarcation lines – but remains one property. I have never checked if the farms themselves appear in both municipal rates rolls, but certainly they have ward councillors from different municipalities on the same land parcel.

If you want to rectify the situation, you have to apply to amend the demarcation limits of the city and follow that process.

Regards

Peter

From: Africa [mailto:africa-bounces at lists.osgeo.org] On Behalf Of Chris Kirchhoff
Sent: Wednesday, July 20, 2016 9:12 AM
To: 'Africa local chapter discussions'  <mailto:africa at lists.osgeo.org> <africa at lists.osgeo.org>
Subject: Re: [OSGeo Africa] Municipal boundary demarcation

Thanks Aslam,

I have downloaded the shape files from the Demarcation board website and the Government Gazette 

The problem that arises is that the Demarcation board  Shape file Municipal  boundary line , the property boundary line based on the Surveyor General digital boundary data and the actual WGS 84 coordinates as defined on the approved Surveyor General diagram that define the property boundary are not consistent.

The Demarcation board  Shape file municipal  boundary line shows the Tshwane municipal boundary running inside a farm boundary by some 30m. 

This farm is supposed to be inside Johannesburg municipality.

The Johannesburg municipality wishes to build a 30m wide road along the farm boundary but now sees that part of the road would fall inside Tshwane municipality according to the Demarcation board  Shape file municipal boundary line.

I would assume the obvious response  is that the Municipal boundary should be contiguous with property boundaries,  however I can find no legislation that clearly sates this ?

Would you have some thoughts on how to resolve  this ?

……………………………………...

Chris Kirchhoff
Professional Land Surveyor
Tel : 082-773 4868
 <mailto:chris at kirchhoffsurveyors.co.za> chris at kirchhoffsurveyors.co.za
 <http://www.kirchhoffsurveyors.co.za/> www.kirchhoffsurveyors.co.za

We believe good spatial information leads to superior planning, diminished project risks, improved feasibility assessments and efficient resource utilisation.

From: Africa [mailto:africa-bounces at lists.osgeo.org] On Behalf Of Aslam Parker
Sent: 20 July 2016 08:38 AM
To: Africa local chapter discussions <africa at lists.osgeo.org <mailto:africa at lists.osgeo.org> >
Subject: Re: [OSGeo Africa] Municipal boundary demarcation

Dear Colleagues

The Municipal Demarcation Board  <http://www.demarcation.org.za/> http://www.demarcation.org.za/  is the only authoritative source of Demarcation data in South Africa

The Board’s mandate derives from:

The Constitution Of The Republic Of South Africa, 1996 (Act No 108 Of 1996). 

The Board is mandated in terms of section 155(3)(b) to determine municipal Boundaries independently. 

Local Government: Municipal Demarcation Act, 1998 (Act No 27 Of 1998)

The latest boundary data (shapefiles) can be downloaded from http://www.demarcation.org.za/index.php/downloads/boundary-data 

We are also encouraged to carefully scrutinise the Section 21 of the Local Government: Municipal Demarcation Act 27 of 1998 the Municipal Demarcation Board which graphically shows re-determined the municipal boundaries.  In most cases the boundary changes seems small and insignificant, but can have significant socio-political, as well as planning implications. http://www.demarcation.org.za/site/?page_id=14588  

A Good example :

“  In terms of Section 21 of the Local Government: Municipal Demarcation Act 27 of 1998 the Municipal Demarcation Board has re-determined the municipal boundaries of Mnquma Local Municipality (EC122) and Mbhashe Local M unicipality (EC121) , by excluding the Administrative areas of Mhlahlana, Nkonkwana,KwaMente, and KwaNkanga from the municipal area of Mnquma Local Municipality (EC122), and by including them into the municipal area of Mbhashe Local M unicipality (EC121).” The example map can be accessed  at http://www.demarcation.org.za/index.php/municipal-boundaries/section-21-maps-and-notices/ec-sec21-dems/1104-dem4037-bpfc-sec21/file 

Aslam Parker | Director: Geo-spatial Information and Professional Support |Chief Directorate: National Geo-spatial Information | Department of Rural Development and Land Reform |  <http://www.ngi.gov.za/> www.ngi.gov.za| Cape Town|

Tel +27 21 658 4302| Fax +27 21 689 1351| Mobile 082 331 8501| aslam.parker at drdlr.gov.za <mailto:aslam.parker at drdlr.gov.za> 

From: Africa [mailto:africa-bounces at lists.osgeo.org] On Behalf Of Lydia du Toit
Sent: 20 July 2016 07:44 AM
To: Africa local chapter discussions
Subject: Re: [OSGeo Africa] Municipal boundary demarcation

Hi Chris, 

Contact the Demarcation Board, or download from their website.

They have the 2011 and 2016 boundaries available.

Regards

Lydia Du Toit (Pr GISc)
Mobile: 0832713158
Email: Lydiadt at mweb.co.za <mailto:Lydiadt at mweb.co.za>  or

From: Chris Kirchhoff <mailto:chris at kirchhoffsurveyors.co.za>  

Sent: Wednesday, July 20, 2016 5:41 AM

To: 'Africa local chapter discussions' <mailto:africa at lists.osgeo.org>  

Subject: [OSGeo Africa] Municipal boundary demarcation

Hi

Is there a formal/ legal source of municipal boundary positions especially for boundary between Johannesburg and Tshwane municipalities 

Thanks

Chris

……………………………………...

Chris Kirchhoff
Professional Land Surveyor
Tel : 082-773 4868
 <mailto:chris at kirchhoffsurveyors.co.za> chris at kirchhoffsurveyors.co.za
 <http://www.kirchhoffsurveyors.co.za/> www.kirchhoffsurveyors.co.za

We believe good spatial information leads to superior planning, diminished project risks, improved feasibility assessments and efficient resource utilisation.

From: Africa [mailto:africa-bounces at lists.osgeo.org] On Behalf Of Gavin Fleming
Sent: 19 July 2016 11:13 AM
To: africa at lists.osgeo.org <mailto:africa at lists.osgeo.org> 
Subject: Re: [OSGeo Africa] QGIS splitting lines at intersections

On 19/07/2016 11:05, Zoltan wrote:

Hi Gavin,
I did see the one using "another layer", but that is problematic as when one is digitising (say) a town road network you would want to honour the straightness of the roads and then intersect them afterwards.

If you're doing it while digitising I would rather set up snapping perfectly then node intersections while digitising. As simple as stopping a line and starting a new one instead of just clicking a vertex at an intersection. 

Hence "popping out" to other facilities just messes up your work-flow.

Will look at the scripting options  - for now this is just a training exercise in teaching digitising principals.

Thanks & keep well,
Zoltan

-- 

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