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Perspective of Instream Flow Policies

The newly proposed policy is somewhat unclear about diversion of subsurface flows – adjacent to any water course. There is language regarding subsurface flows in a defined channel (see North Gualala Water Company Decision – CAG worked on – you need a water law book for this). This is a basic part of Water Code anyway.

In addition, collection/impoundment of any surface water in a swale or derpession is in the juridiction of the State.

This policy is complicated, with many conflicting implications. It will take weeks to get some coherent language together.

Also waiting to hear more from DFG and NMFs.


Thanks very much for that message. A very important message, indeed. I have two thoughts in response:

1. The two definitions in the Basin Plan clearly cover the universe of “streams,” because of the statement in the paragraph defining ephemeral streams that “any water course that does not meet [the definition of ephemeral stream] is to be considered a perennial stream.” But the definitions in the Instream Flow Policy appear to me to not cover the universe. I think we all have observed streams that neither “flow only in direct response to precipitation” (the definition of an ephemeral stream) nor have “flowing water year round during a typical year” (the definition of a perennial stream). I observe such a stream on my neighbor’s property. It flows for 9, 10 or 11 months during a typical year. It doesn’t flow “year round” and it doesn’t “flow only in direct response to precipitation.” Under the Basin Plan, clearly it would be “considered” a perennial stream, but I wonder how it would be considered under the Instream Flow Policy. Anybody know? I know there are some systems out there that have three definitions, the third being “intermittent.” But I gather from the quotations in your message that the Instream Flow Policy doesn’t have that category.

2. The article from the Anderson Valley Advertiser, IMHO, is not a model of objectivity. Nevertheless, I am very concerned about the concept of creating a state-endorsed group comprised of apparently only diverters. The author of the article understates things when he says “A watershed group is made up /only/ of the people who want the water!” He should have said “made up only of the people who want *to divert* the water.” Is this a wholesale abdication by the Water Quality Control Board?

Bob (Burke of AGVWC)

Perspective on Instream flow policies

Alan, Jane, et al,

Here’s my homework from the last SCWC meeting.

Perennial and Ephemeral streams –

In the Basin Plan –

Ephemeral Stream – Any observable water course that flows only in direct

response to precipitation. It receives no water from springs and no long-continued supply from melting snow or other surface sources. Its stream channel is at all times above the local water level. Any water course that does not meet this definition is to be considered a perennial stream for the purposes of this policy.

Perennial Stream – Any stretch of a stream that can be expected to flow continuously or seasonally. They are generally fed in part by springs.

In the instream flow policy –

Ephemeral Stream – A stream or part of a stream that flows only in direct response to precipitation. It receives little or no water from springs, melting snow, or other sources. Its channel is at all times above the water table.

Perennial Stream – A perennial stream has flowing water year round during a typical year. The water table is located above the stream bed for most of the year. Groundwater is the primary source of water for stream flow. Run-off from rainfall is a supplemental source of water for stream flow.

The differences in definitions are very important. For septic systems there is a 100′ setback from perennial streams and a 50′ setback from ephemeral streams. We fought the county for over two years re: a septic system they wrongly approved, in part because they claimed a stream within 100′ of the site was ephemeral, not perennial. There is a spring directly across from the septic site that feeds this stream year round, albeit not with a large amount of water. We live in a waiver prohibition area re: septic systems (which the county has ignored more than once) because of the fragile nature of our community water supply. This issue went all the way to the Regional Water Quality Board where we lost because WQB granted two waivers to the applicants – 1. reduced setback from the perennial stream to 70′. and

2. Allowed the system to be installed on a cut bench that was created on a slope of over 40%.

Changing the definitions of ephemeral and perennial streams gives both the county and the state a little more leeway in skirting the issue. I do not know if the instream flow policy definitions constitute a change in the Basin Plan.

And here is a transcribed copy of the article I mentioned regarding the Instream Flow Policy. It is from the Jan. 2 issue of the Anderson Valley

Advertiser. Perhaps a valid perspective re: who’s in charge here?

John Roberts – AGVCWC.