V Notch Weir Information (for the Rosario Diversion From Cascade Creek)


* The volume on the water right varies by month:

flow           dates                height of 90 degree weir (from http://www.lmnoeng.com/Weirs/vweir.htm)
3.0 CFS Nov - Jan              1'   0 7/8"
2.0 CFS Oct, Feb, Mar       0'   11"
1.0 CFS Apr - June, Sept    0'   8 1/4"
0.5 CFS July, Aug               0'   6 1/4"          (0.133 CFS of this was converted to domestic drinking water in March 2002)

The V Notch weir height is only valid if when the head of the undisturbed water level in the settling pool above the weir is compared to the bottom of the weir. Do not measure the water level directly at the weir.  The water must be able to settle in a deep pool above the weir and flowthrough it without any obstruction from gravel, sediment or accumulation of debris.

Calculations to show 1204 Acre ft/year.
The total of 1204 acre ft is specified in the water right certificate.
This corresponds to a draw of more than 6 feet in Mountain lake!

Here is diagram of a simple V notch weir to insert into a culvert
How to convert CFS to acre ft


Olga Water Users Inc. home page
Details of Mountain Lake conservation Plan

More notes on water flow measurement:
Link to the United State Bureau of Reclamation (USBR) web site for design
of ramp flumes (low cost, relatively easy to construct, adaptable to
difference channel X-sections.) This site also lists commercially available
ramp flumes.

http://www.usbr.gov/wrrl/winflume/
email from Lynn Coleman on water flow measurement