Groundwater rise due to development
Groundwater rise due to development
(OP)
In a review of geotechnical recommendations the state geologic society has requested that I model slope stability with an increased groundwater level due to development. Is there any guidlines for estimating the impact of development on the groundwater level.





RE: Groundwater rise due to development
RE: Groundwater rise due to development
Pumping from municipal wells and increased use of paving and roofs sure doesn't fit with a rise of ground water. It drops.
I have seen some effects like this where the development changed the surface water flow, but only in rare cases. For instance a side hill with new roads and the ditches carrying the surface water laterally. Even then, ground water was not raised significantly.
RE: Groundwater rise due to development
RE: Groundwater rise due to development
What about water perching within the compacted fill placed during mass grading? I see this all the time. Combine this with the amount of landscaping water used here in Southern California and we see elevated water issues all the time. The piezometers in the fill will have perched water, while piezometers placed in natural materials twenty or thirty feet away will be completely dry.
Depending on which study you read and/or believe, here in Southern California the amount of landscape watering done in certain areas over the course of the year is equivalent to one to two seasons of average rainfall!
RE: Groundwater rise due to development
Eastern Washington has a lot of loess bluffs that are stable until heavy irrigation occurs near the top. (If you ever fly into Pasco WA (Hanford), you can see the center-pivot irrigation and the slides along the Columbia.) epongra2's concern about the lawn watering may be right on.
RE: Groundwater rise due to development
Based on our climatic conditions, we assume a rise of 3-5 feet in the wetter seasons and irrigation. This can be very site specific though, based on subsurface conditions and topography.
RE: Groundwater rise due to development
As far as groundwater rise or fall, that, really, is a matter of the stratigraphy that you have at site. Normally, development means a lot of paved over space - hence the probability that the groudwater would fall, not rise. Points are well taken that in some conditions as with irrigation and watering for landscaping, this might cause a rise - but it seems to me that for the water to rise in slopes - does that mean that your development is at the top of slopes (as in Washington - Seattle or Vancouver area)??
Anyway the points by others are well considered - I am just interested in how a "geological society" has become involved.
RE: Groundwater rise due to development
RE: Groundwater rise due to development
RE: Groundwater rise due to development
http://geosurvey.state.co.us/