ground water flow into detention pond

[cimmeron]

I am working of a design where the detention pond normal water elevation is lower than the groundwater table and would like some advise on the best way to compute the amount of groundwater that will enter the pond. The water tabel is about 3 feet higher that the normal water level in the pond

 

[dicksewerrat]

Does this pond have a drain to keep the water level down? Your pond will lower the existing water table over time. I'm not sure what you are asking for. Do you want to know how much water will enter the pond during a storm event? Or how much water will drain into the pond during non storm time? or how do I keep the gound water out of the pond?

 

[dirtsqueezer]

If I remember correctly from my college curriculum, a pond will 'daylight' at the same elevation as the water table. There will be a drawdown effect, that is to say, being that your groundwater will have a place to drain, pond levels will be higher leaving you with less water in the surrounding land ie. a slightly lower water table.

I have seen equations for calculating the water level in a well that demonstrates the same effect, only on a smaller scale. It's possible a modified model would apply. If I find any applicable data, I'll let you know.

 

[dicksewerrat]

You will have to test the soils for their ability to delive water, I don't remember the proper term. Using that number, the water level difference and the area of soil above the pond and below the water wable start to plot the drawdown curves. You may have to let this drawdown take ayear to stabilize.