Definition - What does Bank Storage mean?
Bank storage can be defined as water that is absorbed and stored in the bed and banks of a lake, river or reservoir during periods of high ground water and later returned to the water body during periods of low ground water. Bank storage takes place during storm precipitation, water release from a reservoir or rapid snowmelt. This process of rise and fall in bank storage is very important to reduce flood peaks and to supplement stream flows.
If pipelines are to be installed through such areas, trenchless construction methods such as horizontal directional drilling (HDD) should be utilized that do not disturb the balance maintained by bank storage.
Trenchlesspedia explains Bank Storage
The bank storage process is facilitated by precipitation, snowmelt and reservoir water release. If the rise in high stage doesn't go over the stream banks, the amount of water that seeps into the stream banks as bank storage returns back to the stream within days or weeks. This absorption of stream water to bank storage and the release of the water back into the stream after a period of time helps in reducing peak during flooding and later helps supplement the stream flow.
On the other hand, if the water during high stage overflows the bank and floods large land surface area, water table will get recharged throughout the flooded area.
This results in longer duration of flow back to the stream, in some cases months or years because the path of the water back to the stream will be longer than that from the bank storage to the stream.