Originally Posted by basil
With more recent dams and with more demand for water, we won't have so many high water days as in the past, I think.
I was thinking about that. I mean 20k cfs is a lot of water, I mean A LOT OF WATER. 20k cfs is about 40k acre-feet per day. I wonder whether human influences really impact peaks on high water years. Clearly they impact the shoulder seasons and low flows (sometimes for the better, from a flow perspective).
Not trying to start an argument, just trying to understand what the sensitivities are in the natural system.
Water Supply Storage (excluding flood):
Dillon: 254k af
Cheeseman: 79k af
Green Mountain: 154k af
If Dillon were empty, it would take only 6.5 days to fill with 20k cfs. And Dillon isn't empty, in fact most reservoirs are near full.
What's changed since the 80's? Less precip (we have been in a prolonged dought), or are there major water supply projects that have gone online in the past 30 years? Can anyone list them, I'm just curious?
Growth in mountain areas impacts flows, but more on the side of base flow than peaks. Say there's 25k people in Summit, 50k in Eagle, call it 500k people in the Colorado River drainage above Big Sur. (maybe an over estimate) At 80 gallons per day per person, that's 122 af/day or about 62 cfs of use and maybe 6.2 cfs of consumptive use (impact to the river). That's like boating on the morning dew. Not much irrigation going on right now, so we'll leave that out.
I guess what I'm getting at is that Big Sur runs when mother nature wants it to, development and dams be damned. BIG SNOW YEAR runoff seems to be many orders of magnitude bigger than human impacts on the river.