A detailed understanding of your lands contour is critical to sustainable use of water. We have been doing significant research lately on low-cost methods to obtain highly detailed contour maps of land.
Below is a contour map generated last week of Six Hands Farm. It has 1 meter contour lines on top of an elevation gradient, which makes it easy to identify features of the property. More or less detail can be provided, including deep-zooms into specific areas of interest, based on requirements. (Click image to view larger size).
The data used to generate this map is accurate to around 5cm, it varies in accuracy a bit more in areas of high foliage/tree cover where is is harder to determine the actual ground elevation.
This data was captured via an aerial drone following an automated set of waypoints at 165ft altitude using a 12mp camera. The total capture time for ~55 acres was under 25 minutes. Lower altitudes can be used for higher accuracy.
Processing of the data was done using a variety of commercial and open source tools, and takes about 24 hours.
The low cost of these captures makes this data accessible to most land owners. In a consulting setting this capture could be done for less than $1000 with a two day turnaround.