Having trouble importing contour data using usgs website
Joaquin,
Welcome to the Autodesk Forums.
Need more information. What is your data and how were you importing it? Can you post your data, or a link to it?
Dave
Dave Stoll
Las Vegas, Nevada
NVIDIA Quadro P5000 16GB
Windows 10 Pro 64 / Civil 3D 2025
Please describe the ‘contour data’ because that could mean different things. Vector data? Raster? And downloaded from where on USGS website? URL?
Chicagolooper
Accepted solution
Unfortunately i don't think you have contour data,. What you've downloaded is an elevation product., such as a 1 arc-second DEM, in NAD83 datum, Lat/Long format, which is a raster. USGS doesn't have anything named 1 ft x 1 ft contours. Also, the USGS DEMs are not in quads. If you want data from a quadrangle, you need to go to the Topo Map Data and Topo Stylesheet section. To get contour 'lines' you'll need to get the Elev_Contour shapefile. You can either use the shapefile as-is or import it and convert it to cad line work during in the import process.
As you can see, there are possibilities when using DEMs. You can even combine the DEM with contour lines.
Chicagolooper
Accepted solution
They are georeferenced to NAD83 lat/long or EPSG 4269. If you are drawing in state plane, assign your state plane to modelspace. When you use data connect to connect to the elevation raster (that super big file that with begins with w001 and ends with extension .adf) make sure the raster has a coordinate system LL83 (EPSG4269). If it doesn't you'll need to edit the raster so that it does. It's perfectly OK if the 'input' coordinate system doesn't match the modelspace coordinate system--they don't have to match because Civil3D/Map3D will perform a transformation for you.
If you want the get the contours directly from the quad, you can do that too from the USGS webite. You may, or may not, have to get more than one quad and put the quads side-by-side if you have a wide coverage area.
Chicagolooper
Joaquin,
Well, that DEM is a Monster! 13 million points! And C3D stores that huge surface in an external "MMS" file. (483 MB's!)
I'm guessing the step you missed was identifying the Coordinate System of that DEM. Thusly:
Dave
Dave Stoll
Las Vegas, Nevada
NVIDIA Quadro P5000 16GB
Windows 10 Pro 64 / Civil 3D 2025
Looks like you're in Brown County. When I work with contours downloaded from the USGS site, you must understand that these contours are (1) NOT survey grade and (2) they cover a wide area. Do you have the lat/long of the 300-ac site? Simply 'eyeball' the center and get the lat/long. Once you provide the lat/long I can give you two options. Keep in mind, the downloads from USGS are NOT survey grade--to get survey grade you need a surveyor--no exceptions.
Chicagolooper
Joaquin,
To tame that Big Ol' DEM (Texas Talk), add a Data Clip to your Surface Definition before bringing in the DEM.
For more Elevation Data you can check >>>TNRIS<<<.
Edit: Looks like the TNRIS Site doesn't have Elevation Data, but you might still find something useful there.
Dave
Dave Stoll
Las Vegas, Nevada
NVIDIA Quadro P5000 16GB
Windows 10 Pro 64 / Civil 3D 2025
Joaquin,
This is fun. After further nosing around in TNRIS, if you search in the Kempner Quadrangle you'll find Contours and Elevation Points covering your ranch. They may or may not be any better than the data from the USGS site.
Dave
Dave Stoll
Las Vegas, Nevada
NVIDIA Quadro P5000 16GB
Windows 10 Pro 64 / Civil 3D 2025
You can easily get the contours from the same USGS site, but instead of downloading w0001001.adf from n32w099 which is an Elevation Product (Raster 1mx1m), you should download from Topo Map Data and Topo Stylesheet instead.
If you download the raster, regardless of how small the raster is, you'll still have to generate the contours from the raster. By downloading the Topo Map Data and Topo Stylesheet, you'll get the contours immediately, albeit as a shapefile. If you wish, you can even import the shapefile to C3D/M3D and automatically convert them into Cad polylines during the import procedure which will conveniently allow you to work exclusively with Cad entities and not a combination of Cad and ESRI objects.
To get the contours without dealing with that huge raster, follow the ATTACHED INSTRUCTIONS.
Chicagolooper
To further illustrate why you should download contour shapefile and not elevation data, see image-1.
The elevation data is the green raster, and the contours, which are yellow, are vectors and are limited to the extent of a 7.5 minute topo quadrangle, in your case Kempner Quad. If you download the raster, you're getting more data, way more data, than you need, image-2. You can make contours from the raster but why do that when you can get download the contour shapefile itself?
The example below illustrates both raster and the vector data (contours) overlaid one another. You can clearly see the contours are more than sufficient in providing the necessary coverage for your 300-acre site. The aerial photo with the blue parcel boundaries was downloaded from Lampasas County Central Appraisal District (lampasascad.org), View County Maps. The RED geomarker, labeled The Site, is in the middle of your project and was located using the coordinates you provided in post #12. If you look closely at image-2 above, you can see the RED geomarker amongst the yellow contours.
Chicagolooper
