4 ms·

A lot of the water in the west comes from snowpack. But there's not going to be much snow anymore, hence there'll be less water.

by sosull 4y ago

baggy_trough 4y ago
That doesn't follow because rain fills reservoirs the same as snow. One difference, though, is that snow releases as it melts during the spring/summer.
- ivalm 4y ago
  Snow is localised and melts into captured streams. It gets refilled because high alt + low temp preferentially causes rainfall/fog that replenishes the snowpack. If fewer rain cloud condense on the peak then it just rains more dispersed which leads to much less efficient capture (some absorbed by the ground, some rains over ocean, evaporation is faster when you have water spread over large area so fraction of time spent in liquid form is smaller, etc).
- rconti 4y ago
  Right. Snowpack is a form of massive reservoir. Snowmelt through the course of the year allows us to constantly release water from human-made reservoirs while their levels stay the same. There is still snow in the Sierra today, and in a typical year snow stops falling in April. Rainfall is much, much harder to capture, and the release curve is completely different; you can very quickly go from flooding to bone-dry.
- mdtusz 4y ago
  It makes a big difference. Imagine watering your favourite plant once per month with 4 litres of water, vs watering weekly with 1 litre of water. The snowpack melt cycle allows for gradual watering of the surrounding areas. Not directly answering the question for reservoirs, but the rapid loss of snowpack and glaciers has a massive impact on the environment.
- lanstin 4y ago
  So that a system of dams that works for snow pack would need to be scaled up five x or ten x to collect all that flow in less time.
thehappypm 4y ago
Citation needed. Climate change might create mega storms — more water in the air to fall as snow
- bart_spoon 4y ago
  But more rain doesn't necessarily equate to more ground level water supply. Rain more easily evaporates, and can then be transported elsewhere. Snowpack historically is critical to water supplies in the West because it slowly melts and provides a steady source of water throughout the dry season. A mega storm with no way to capture the water AND prevent it from evaporating in the dry season can still provide far less water than an equivalent amount of snowpack.
- sosull 4y ago
  There's an article in the Washington Post today: > "The root of the problem is an ongoing, 23-year drought, the worst stretch for the region in more than a millennium. Snowpack in the mountains that feed the 1,450-mile river has been steadily diminishing as the climate warms. Ever-drier soils absorb runoff before it can reach reservoirs, and more frequent extreme heat hastens evaporation." https://www.washingtonpost.com/climate-environment/2022/08/16/colorado-river-bureau-of-reclamation/ https://www.washingtonpost.com/climate-environment/2022/08/1...

A lot of the water in the west comes from snowpack. But there's not going to be much snow anymore, hence there'll be less water.

by sosull 4y ago

A lot of the water in the west comes from snowpack. But there's not going to be much snow anymore, hence there'll be less water.

baggy_trough 4y ago

That doesn't follow because rain fills reservoirs the same as snow. One difference, though, is that snow releases as it melts during the spring/summer.

ivalm 4y ago
Snow is localised and melts into captured streams. It gets refilled because high alt + low temp preferentially causes rainfall/fog that replenishes the snowpack. If fewer rain cloud condense on the peak then it just rains more dispersed which leads to much less efficient capture (some absorbed by the ground, some rains over ocean, evaporation is faster when you have water spread over large area so fraction of time spent in liquid form is smaller, etc).
rconti 4y ago
Right. Snowpack is a form of massive reservoir. Snowmelt through the course of the year allows us to constantly release water from human-made reservoirs while their levels stay the same. There is still snow in the Sierra today, and in a typical year snow stops falling in April. Rainfall is much, much harder to capture, and the release curve is completely different; you can very quickly go from flooding to bone-dry.
mdtusz 4y ago
It makes a big difference. Imagine watering your favourite plant once per month with 4 litres of water, vs watering weekly with 1 litre of water. The snowpack melt cycle allows for gradual watering of the surrounding areas. Not directly answering the question for reservoirs, but the rapid loss of snowpack and glaciers has a massive impact on the environment.
lanstin 4y ago
So that a system of dams that works for snow pack would need to be scaled up five x or ten x to collect all that flow in less time.

thehappypm 4y ago

Citation needed. Climate change might create mega storms — more water in the air to fall as snow

bart_spoon 4y ago
But more rain doesn't necessarily equate to more ground level water supply. Rain more easily evaporates, and can then be transported elsewhere. Snowpack historically is critical to water supplies in the West because it slowly melts and provides a steady source of water throughout the dry season. A mega storm with no way to capture the water AND prevent it from evaporating in the dry season can still provide far less water than an equivalent amount of snowpack.
sosull 4y ago
There's an article in the Washington Post today: > "The root of the problem is an ongoing, 23-year drought, the worst stretch for the region in more than a millennium. Snowpack in the mountains that feed the 1,450-mile river has been steadily diminishing as the climate warms. Ever-drier soils absorb runoff before it can reach reservoirs, and more frequent extreme heat hastens evaporation." https://www.washingtonpost.com/climate-environment/2022/08/16/colorado-river-bureau-of-reclamation/ https://www.washingtonpost.com/climate-environment/2022/08/1...