According to the Alaska Department of Fish and Game, there are over three million lakes in Alaska with a surface area larger than five acres!

Currently, in OpenStreetMap, there are roughly two hundred and forty two thousand elements in Alaska tagged with natural=water, which is a generic tag for an area filled with water.

So, I have decided to embark on mapping natural areas filled with water!

I use the USGS elevation data for alignment, as it seems to have the best alignment to where things actually are on the ground. The USGS imagery is sometimes aligned with the elevation data, but sometimes is not, so the Mapbox and ESRI Clarity imagery is instrumental in areas where it is more accurate to the elevation data.

The National Map Topographic is extremely useful for some lakes, for those where it matches the elevation data well. Often though, it does not match the elevation data.

I posted about this in the OpenStreetMap Slack, and have received help from Watmildon, who has been very kind and extremely helpful! He is helping with the technical aspects of this, and has brought the 3DHP program to my attention, a hydrology program from USGS that is based on elevation data and thus much more accurate than the older NHP data. He is helping to setup a website where one can view the differences between OpenStreetMap, NHP, and the 3DHP, and eventually I hope to be able to overlay the 3DHP data onto an OpenStreetMap editor so I can use it to assist the mapping.

Thanks for reading and happy mapping!

Sources:

https://www.adfg.alaska.gov/index.cfm?adfg=rivers.main

https://taginfo.geofabrik.de/north-america:us:alaska/search?q=natural%3Dwater

https://www.usgs.gov/3dhp