Tag Archives: hydraulic head

Springs and seeps

Facebooktwitterlinkedininstagram

Blue Spring in central NZ. Groundwater supplied is 50-100 years old.

It rains quite a bit on Mamaku Plateau, the tableland underlain by volcanic debris that was  deposited violently 240,000 years ago; an eruption that also gave rise to Lake Rotorua caldera (central North Island, New Zealand). Some of that rain seeps into the myriad fractures, nooks and crannies, and heads west as groundwater. Fifty to 100 years later that same water emerges, chilled to a cool 11oC, at Blue Springs (about 40km west of Rotorua). Spring water here flows at 42 cubic metres per minute (9,240 gallons per minute), enough to maintain a decent-sized stream (Waihou Stream). Continue reading

Facebooktwitterlinkedininstagram
Facebooktwitterlinkedin

A misspent youth serves to illustrate groundwater flow

Facebooktwitterlinkedininstagram

The mystery of groundwater flow solved!

Groundwater is always on the move. Under some conditions, in fractures or other large conduits, it can move quickly; almost at a walking pace. Under other conditions it moves inexorably slowly, like fractions of a millimeter a year. Regardless, it is always compelled to move. Movement requires energy.  Where does this energy come from?  What drives the flow of groundwater?  Answers to these questions provide the foundations to the science of hydrogeology. Continue reading

Facebooktwitterlinkedininstagram
Facebooktwitterlinkedin