How drastic are changes in water tables in areas not neighbored by rivers etc? 3

[IJR]

I was just curious, how much is a water table likely to change given that there is no lake, no rivers, no mountains around the site?

Any study on this issue.

Sometime we overdesign for fear that water table might rise significantly.

respects
IJR

 

[Ron]

The water table is affected by soil type, vegetation, terrain slope and other factors, moreso than proximity to a body of water.

The USDA Soil Conservation Service (I think it might be called something else now) has some good info on the determination of seasonal high groundwater. One estimate I've seen used quite a bit is to determine the present water table and add two feet. That can be grossly inaccurate because of the variations in soil type, vegetation, piezometric surface and a variety of other variables.

 

[emmgjld]

The problem includes what the new construction does to the drainage,
new excavation & fills creating perched waters,
new concentrations of surface waters (think roof runoff, pavements & retention/detention areas),
landscaping issues (irrigation & plant transpiration),
You ask the questions which has too many variables.
I agree with Ron, the idea of adding 2 feet to existing can be "grossly inaccurate".

 

[oldestguy]

An interesting factor deals with water supply wells. They sure can cause some funny things. Take a lake where there are some nearby high capacity wells. Water table under the lake may be far down.

 

[nbr1]

Thin clay layers, especially at shallow depths, can create perched groundwater conditions in sands. I agree with others...many variable involved.