Don (Vilaine)


The River Don is a river in Brittany, France. It is a tributary of the river Vilaine.

Geography

The River Don rises in the steppes of Brittany, near the towns of Saint-Michel-Chef-Chef and Chanveaux in Maine-et-Loire. The river flows west, passing through the towns of Saint-Julien-de-Vouvantes and Petit-Auverné, where the Little Don joins it. The river flows through the towns of Isse, Treffieux and Jans, where the River Cone joins it. After passing under the RN 137, it continues toward Marsac-sur-Don, Guémené-Penfao and then Massérac, where it empties into the River Vilaine at the border of Loire-Atlantique and the Ille-et-Vilaine.

Hydrology

The River Don has a very irregular flow rate over the months, like other tributaries of the River Vilaine.
The flow of the Don was observed and documented in a study which took place over a period of 25 years. The results were taken from near the Don's confluence with the Vilaine. It showed that the average annual flow rate 3.77 cubic meters per second. However, the Don has strong seasonal fluctuations in flow rates, in common with other tributaries of the Valaine, and other rivers of Brittany. The highest waters occur in winter, and are characterized by average monthly rates ranging from 5.95 to 11.7 cubic meters per second. From March, the flow decreases rapidly, to the lowest water in summer from June to mid-October. The results are clearer in the bar graph, below.

Average flow of the River Don
Monthly averages over a 25-year period, taken from near its confluence with the Vilaine

Colors=
id:lightgrey value:gray
id:darkgrey value:gray
id:sfondo value:rgb
id:barra value:rgb
ImageSize = width:500 height:300
PlotArea = left:40 bottom:40 top:20 right:20
DateFormat = x.y
Period = from:0 till:12
TimeAxis = orientation:vertical
AlignBars = justify
ScaleMajor = gridcolor:darkgrey increment:2 start:0
ScaleMinor = gridcolor:lightgrey increment:1 start:0
BackgroundColors = canvas:sfondo
BarData=
bar:Jan text:January
bar:Feb text:February
bar:Mar text:March
bar:Apr text:April
bar:May text:May
bar:Jun text:June
bar:Jul text:July
bar:Aug text:August
bar:Sep text:Sept.
bar:Oct text:October
bar:Nov text:Nov.
bar:Dec text:December
PlotData=
color:barra width:30 align:left
bar:Jan from:0 till: 11.70
bar:Feb from:0 till: 8.66
bar:Mar from:0 till: 6.06
bar:Apr from:0 till: 3.78
bar:May from:0 till: 2.29
bar:Jun from:0 till: 0.93
bar:Jul from:0 till: 0.35
bar:Aug from:0 till: 0.12
bar:Sep from:0 till: 0.24
bar:Oct from:0 till: 1.07
bar:Nov from:0 till: 3.23
bar:Dec from:0 till: 6.85
PlotData=
bar:Jan at: 11.70 fontsize:S text: 11.70 shift:
bar:Feb at: 8.66 fontsize:S text: 8.66 shift:
bar:Mar at: 6.06 fontsize:S text: 6.06 shift:
bar:Apr at: 3.78 fontsize:S text: 3.78 shift:
bar:May at: 2.29 fontsize:S text: 2.29 shift:
bar:Jun at: 0.93 fontsize:S text: 0.93 shift:
bar:Jul at: 0.35 fontsize:S text: 0.35 shift:
bar:Aug at: 0.12 fontsize:S text: 0.12 shift:
bar:Sep at: 0.24 fontsize:S text: 0.24 shift:
bar:Oct at: 1.07 fontsize:S text: 1.07 shift:
bar:Nov at: 3.23 fontsize:S text: 3.23 shift:
bar:Dec at: 6.85 fontsize:S text: 6.85 shift: