Current: with or against?

If you have to row for an hour on the Ringvaart of the Haarlemmermeer, it is useful to know if there is a current. Only if the dewatering is “on”, there is flow, in which you will in many cases halfway the flow with it and after halfway possible against. Incase the pumping station at Spaarndam is on this will last for a longer part. The last part will often have the current against you. We can best explain how this can be done with the attached map.

Whether or not the pumping station is on can be found on the website of the water board via this link: http://rijnland.webgispublisher.nl/Viewer.aspx?map=Meetpunten http://rijnland.webgispublisher.nl/Viewer.aspx?map=Meet points If you click below “Afvoer van water”, you can see whether the drains are on. If there is no drainage at pumping station Halfweg and Spaarndam then the flow is negligible.

If only the pumping station is halfway on, this is the flow (branch is pink number on photo and arrow is flow direction):

 

Branch     m/s    km/u

115     0,08    0,29

114     0,09    0,32

128     0,12    0,43

134     0,28    1,01

126     0,00    0,00

If the pumpingstations of Halfweg en Spaarndam are on, this will be the current (branch is pink number on photo and arrow is flow direction):

Branch     m/s    km/u

115     0,25    0,90

114     0,16    0,58

128     0,07    0,25

134     0,47    1,69

126     0,14    0,50

(source: Water Authority of Rijnland)