When Does a Stream Become a Lake?

June 26, 2008

Question: I like to fish in lakes where there is freshwater stream inflow. But since regulations differ depending on whether you’re fishing in a stream or in a lake, at what point does a stream become a lake? (Stan J. via e-mail)

Answer: Technically, where there’s a current, the body of water is considered to be a “stream.” At the point where the water backs up and becomes slack (no current), the body of water is defined as a “lake.” Remember that this is defined by the water flow and not necessarily by a geographical area; therefore, this point can change depending on the elevation and time of the year. For example, if it’s the end of the summer and you’re standing in a half-full reservoir, if the water has a current, you’re fishing in a stream!

 

This answer is 110% useless and offers zero clarification. All she did is paraphrase the question. 

Makes sense ...  if the water is moving, it is a stream.  Yes, that geographical location changes throughout the year. 

Yeah but who decides when the water is or is nor flowing?  It would require sensitive hydrologic instrumentation to quantify that. And anytime releases are being made from a reservior, that would constitute flow.

Too impractical to quantify.

OK, I'm so confused.  F&G considers Baum Lake a lake or at least they don't cite you for fishing it when stream season is closed, but by the definition of a stream being flowing water, it should be considered Hat Creek.  So maybe the difference between a stream and a lake is a matter of semantics and just boils down to the acceptable name given to that body of water. 

By that same standard, the Salinas River is not currently flowing; the lagoon is merely ponded with no inflow and no surface outflow. So Does this mean that the river is now a lake?

How about Natomas Lake?  A lake that probably has as much current as the definition allowed for a river. 

Personally, I think a definition would be where a body of water is at the same elevation across it's surface.  Meaning that no matter where you are on the water, you will be at the same elevation as any other point on the water.  There could still be a current, with the inflow equal to the outflow, more or less. 

Personally, I think a definition would be where a body of water is at the same elevation across it's surface.  Meaning that no matter where you are on the water, you will be at the same elevation as any other point on the water.  There could still be a current, with the inflow equal to the outflow, more or less. 

This is how it always was when I was growing up fishing lake almanor. That's how the game warden enforced it.

How would you define a streambed where water is not flowing, has pools of water, not connect to one another, that contain stranded fish?  No surface inflow or outflow, all at the same elevation.

How would you define a streambed where water is not flowing, has pools of water, not connect to one another, that contain stranded fish?  No surface inflow or outflow, all at the same elevation.

ephemeral stream
intermittent stream
arroyo
gulch




as far as river or lake, some, like baum lake and keswick reservoir have definitions prescribed in the regulations, and the imperceptible movement behind a dam makes no difference to a lay-person unless trying to get something from the minutia of the verbage.  so if the water appears to be flowing, but not backed up...then stream.  but the point of equal elevation in a lake, even with inflow eddys would likely be considered by a warden and judge to be a lake.


2c