In my perspectives, if you want land for future projects that involve water harvesting and maintenance such as pond/lake, I assist my friends in doing:
1. Evaluation of both largest known historical precipitation events (flood) and annual precipitation (yearly that provide adequate water harvesting) above the drought threshold level (which is cycle every 15 to 75 years). If there's an active spring to feed water onto your property, a massive plus. Know where the spring source is coming from, and how long the spring has been there.
2. Topography to evaluate water collection within a watershed, utilizing a retention basin technique for desilting/nutrient trapping, before introducing captured water usages. Never purchase flatland unless you have a historical abundant source of water.
3. Know your groundwater depth, water rights volume allotment, and hydrological connection to the local water body(-ies) and tributaries. You can pond your water, but if your water discharge to the local water of the U.S. or directly impact groundwater, you may get a nice letter from the Dept. of Natural Resources/Fish & Wildlife that may lead you to prison.
4. Now, adding to topography, soil types. For water harvesting, you want to minimize water loss. Can't have soil that drains quickly. This is also important to utilize plants as natural filtering and nutrient reducers, unless you have plenty of money to control the nutrient issues yourself.
5. This may not be important, but off-grid pond/lake management, we like to have an area where wind can also be harvested for both power generation and passive aeration, inducing dissolved oxygen into the water.
