free contour map generator

Hey folks, I have been catching up on videos I had missed and found this one from VergePemaculture



It links to a website that offers a free contour map creator http://contourmapgenerator.com

I haven't used this for myself yet, but thought it was worth mentioning here for others to discover. I did a search to see if it had been brought up yet and didn't find it mentioned. So here you go folks.

I am hoping to give it a try soon and will report my experiences. If anyone else has used it please let us know how you liked it.

I am glad that this tool exists. I imagine that it will be very helpful for people.

Unfortunately I live on flat land and did not find this to be particularly helpful. Can anyone else with flat land share their experience with this tool? Maybe I'm just using it wrong?

Free if you have already bought Google Earth Pro, that is.

I just downloaded Google Earth Pro free, I think.  But I can't figure out how to make the contour map program work, which is a shame.

Kathleen

Tried it and it works great. Thank you!

Sorry I don't have internet at my property so couldn't check in this

To answer a few of the things that have come up.

Google Earth pro is a free program, so you don't have to pay for it. There is an option to pay to get "more out of it" but you don't need to.

Also you can set the contour range, I set mine for 2 ft. but am thinking of trying another few maps with different ranges. Once I dial in the right contour I will post a pic of it.

I had to try it twice. The 1st one didn't work and I didn't see any contour map in Google Earth, but the 2nd attempt worked fine. I just want to give it a bit of tweaking to see what the best range is.

If you have a really flat piece of land, you might try seeing if you can go under a 1 ft. I don't know if it will let you do .5 ft but it is worth trying, it is not like it costs you anything.

A similar tool is available here: https://contourmapcreator.urgr8.ch/

I find that which one works better varies wildly from one property to another.

I have used Cal Topo for contours. It is fun to play with.

Works suprisingly well!

Although I would be sceptical about accuracy and precision just for the following reasons:

I guess these tools are based on freely available earth surface data provided by satellites. The best of these datasets (Alos Palsar, to my knowledge), has a resolution of 12.5 m. So a countour interval of 2 m, based on data with a resolution of 12.5 m, is purely based on interpolation and NOT real. Might be enough though for basic planning ...

These free data are always in the form of "digital elevation models", and they represent the entire elevations of the surface at sight, including buildings. So if you live in an urban setting, the contours you get might be very inaccurate or even false due to the buildings around you. On the contrary, the "digital terrain models" have buildings and vegetation removed in post-processing, but this is very difficult to achieve with satellite data and is never the case for free datasets.

Cheerio
Lukas

I think this contour map tool works much better: https://contourmap.app/.
It's much easier to use and the free preview is really good. Plus it has high accuracy LiDAR data.

LiDAR wasn't available where I am, but this was fun!

I suspect the contours are interpolated though as it seems to have not noticed that most of the land is terraced...

Late to this thread, but Lukas's point about surface vs terrain models is worth an update, because it's no longer quite true.

Since 2025 there's a free global bare-earth model: GEDTM30, from OpenGeoHub. It's 30 m resolution, built by combining satellite elevation data with ICESat-2 and GEDI lidar measurements to strip out trees and buildings. So it's a terrain model rather than a surface model, which matters a lot in wooded areas where the older free datasets (SRTM, ALOS) put the "ground" on top of the canopy.

Full disclosure: I build a contour tool, topolines.app, which uses GEDTM30 worldwide and switches to national lidar where it's open (France, Spain, Switzerland, England, the US at 10 m, parts of Germany and Austria). I ran a comparison of GEDTM30 against lidar on a few test areas, including forest, if anyone wants to see where it holds up and where it doesn't: https://www.topolines.app/blog/gedtm30-vs-lidar

That said, Lukas is right on the main point, and it applies to every online tool in this thread, mine included. A 30 m (or even 5 m) grid won't show terraces like Burra's, and 1-2 ft contours generated from it are interpolation. Good for reading the shape of a watershed, finding valleys, ridges and the general keypoint area. For actually laying out swales or keylines on the ground, an A-frame, water level or laser level is still the tool.