The Kilarc Project


Current Events

Project Approach Summary

Ideas for Discussion

Reference Materials


Kilarc Cow History

Community WEB Site

Related Sites and Contacts




Ideas For Informal Discussion

This informal page has ideas being discussed among various people involved in the Kilarc-Cow Creek Project.  This page is full of changing opinions.  We would be interested in your discussion.

There is no a-priori agenda here other than KC LLC would like to operate the Kilarc powerplant for profit and to generate resources to successfully restore the anadromous fish and maintain the Kilarc facility for the community.  How we do this is up to the biology, physics, and economics of the site, and the constraints imposed by resources, private property rights, and the regulatory agencies.

Ideas being discussed (Since July 2007) include:

  • Maintain Kilarc as it is so that it can continue to deliver excellent trout fishing.  It also injects cold water above large salmon and trout spawning and habitat areas making it a valuable source of cold water for the extensive fish habitat below the project area.
  • How to best design the Kilarc Canal fish habitat area to produce O. mykiss of the best genetic mix for the area, and to
  • throw off enough profits so that the Kilarc Foundation can enhance fish habitat over a wide area.


Perhaps nothing is more mysterious at this site than fish.  It is clear that the economics of the site are to be controlled by the fish; primarily anadromous steelhead fish that this site might support - in various ways. The NMFS and CDFG want a lot of water to pass down the bypass to "restore the natural conditions" because, "the natural conditions are best".  Putting significant water down the bypass will make the site uneconomical as PG&E has correctly concluded.

First we are suggesting that the fish that might reinhabit the bypass might be few in that they have to pass up two sets of falls downstream of the Project. The falls are sequential with only a narrow - very narrow chasm between then not affording any passing fish any rest areas while they pass both falls. So with isolated population upstream, the fish surviving there are resident adapted and will not contribute significantly to anadromy. This enhanced population can be compared with what might be done with the revenue from the project for the fish by the Kilarc Foundation.

Second we suggest that the canal can be made into an excellent spawning habitat and this will allow the whole facility to emit more fish of the correct type downstream than would come from the "natural conditions".  This could be studied, and if found useful be a project done in house by Davis Hydro or with university students interested in the problem.

Second the cold water that comes through the hydropower cools downstream habitat for both salmon and steelhead in the Lower Old Cow and Cow Creek proper.  This effect is is about 2 degree Centigrade (PG&E Aq. Bio. Asmt. p. 22) but the habitat that this temperature affects is large and of high quality.  Water temperature is the limiting habitat factor in the Cow, and removing the project may increase the temperature, reducing the available salmon and steelhead habitat more than any habitat created upstream.  Finally, we are working on other projects such as the German Ditch / PG&E water rights issues. These "off-site" projects could be funded through a new non-profit foundation called the Kilarc Foundation.  We have a suggestion for that which is available here in the documents section.

Next we will discuss three issues:

  1. Natural Conditions,
  2. Barriers and Site Contribution to steelhead anadromy, and
  3. Genes.

    1. Natural Conditions

Agency personnel have contend that in the light of no other information, "Natural conditions are best". "The fish have evolved to live in them over millions of years".  We agree, however, in this site there is other information. Specifically, inspection of the bypassed channel revels several physical factors that rule against getting a significant improvement in anadromy from this area. These include
     A. the creek bottom and substrate,
     B. the shape of the walls, and to some extent,
     C. the lateral vegetation.

The Creek Bottom:  The bottom of this Creek in the bypass area is 94% flat bedrock and large boulders (PG&E's Aquatic Biological Assessment Report (Page 22) . The remaining 6 % contained fines,sand, and gravels.  Spawning gravel available within the Old Cow Creek bypass reach main channel was rated fair to good quality for rainbow. This is also described in PG&E's Draft License Surrender Application, Appendix E. p.4). We have visited all of the bypass and can provide pictures of the Creek at about 50 meter spacing. Some typical pictures are in the picture section under Kilarc bypass pictures.  Adding some water back in the this section of the Old Cow creek will have a very small amount of effect on the number of fish that can be produced.  While it may be greater than zero, they marginal effects of the extra 20-40 cfs proposed (depending on availability) may not produce significantly more habitat nor anadromous fish.

The rock bottom inhospitable to fish at all life stages it is also inhospitable to to insects, and macroinvertebrates on which the fish depend for food.

Spawning Gravels

One of the areas for discussion is gravel. Casual observation of the upper regions of the Cow Creek bypass, it appears that there are significant gravels. This is deceptive. The gravel patches are generally not deep, and are intermixed below the surface with impermeable silt, sand, and clays from the immediate canyon walls. For Steelhead spawning, gravels should be clear of sediment to a depths of over six inches, what appears to be good gravel on the surface, is usually deficient when examined in cross section.

Careful examination will show that the best spawning gravels within the Old Cow bypass appear to be within the first quarter mile above the bridge near the powerhouse. It is in this area that the Creek gradient levels out into small fields affording matrix sorting sufficient for good spawning ground formation.

The Valley Shape: The morphology through much of the bypass consists of U-shaped cross-sections and steep incised (V-shaped cuts) channels.  This means that adding more water will not increase the habitat footprint, only increase the depth and velocity of water down the ravine.  While in some areas there will be an increase in habitat from the extra flows, these are offset by the increased velocities in the incised channels reducing the quality of juvenile habitat.  To use the words of one visiting biologist, " they all get blasted out or buried every storm.

Cover: While there is a lot of significant woody debris in the area, there is less overhanging live vegetation. The lack is from four reasons: 1. / The very steep sides of the canyon-like creek channel inhibits bank growth, 2. / The banks are often solid rock and boulders that have not been washed downstream in the spring floods.  This affords no soil for littoral growth. 3./ There is little sunlight in the steep sided stream bed areas, and 4./ There is a significant presence of Mongolian Blackberry bushes that choke out vegetation in areas where banks approach the stream.  Mongolian Blackberries are a major detriment to formation of significant vegetative cover.  Throughout most of the central part of the bypass, most fish cover consists of deep pools, rock ledge and large boulders. WHile this is good for adults, there is little juvenile and almost no spawning habitat.

And again, the "natural conditions" that affect the salmon and steelhead populations are not just he bypass region but also the much, much larger area downstream that will have its temperature raised by a small amount and areas of marginal habitat reduced.

In summary, the natural conditions are a challenge and there may be a better way to produce anadromous fish.

2. Barriers to upstream Migration

Thirteen potential fish passage barriers were identified and evaluated In PG&E's Aq. Bio. Asmt. within the Old Cow Creek bypass reach. These barriers were distributed along the length of the bypass reach. Ten of these were classified as falls or cascade barriers (Table 10); the other three were classified as critical riffles. One impassible barrier is present. This barrier is a 12-ft-high falls identified by CDFG and located 2.7 miles upstream of the Kilarc Powerhouse. Pictures of this barrier are shown in the pictures section of this site. Below the project is the Whitmore falls which forms another nearly impassable barrier in all but very high flows. 

For these reasons, Davis Hydro has focused on how many juvenile fish are emitted downstream and not on the number of returning steelhead an a useful goal or metric. The lack of habitat in the Old Cow Creek and the significant barriers detract - if not completely inhibit upstream migration of steelhead in any significant numbers; so to best answer the question of how to restore or enhance anadromy in the Cow, Davis Hydro is proposing a plan to modify the Kilarc Canal and water delivery system to spawn a large number of juvenile rainbow and have them travel downstream via a fish bypass facility to the Old Cow where it opens out a bit above the powerhouse.  Since the steelhead have a weak homing instinct, their straying behavior will allow them to populate more suitable habitat elsewhere.

In summary, the Davis Hydro plan will spawn and emit a large number of juvenile fish while conduction hydropower as it is now.  We see little or no advantage to increasing flow in the bypass channel in that will not significantly increase habitat nor spawning relative to the production possible in the modified Kilarc system under active management of the hydropower operator.  Increasing water depth and flow in areas that are blocked to upstream migration is not a strategy that will help induce anadromy in the area.

3. Genetics

Is it best to let hatchery fish intermix with the resident - non-migratory fish?  Exactly what fish are being promoted is a big issue.  This has been addressed at length in the recent CDFG EIS that is availablehere. This area has been saturated with hatchery fish for many years.  They currently constitute over 90 % of the fish in the project area. Practice at the Coleman hatchery is, and has been, to select the larger fish to use are egg sources, under the theory that many of these large fish are steelhead simply solely because of the size. The result of this criteria is that there will be a mix of fish with varying anadromous tendencies.  The mix is unknown and no statistical sampling program is in place and no data is known to exist addressing what percentage if amy is of an anadromous origin.  The local fish therefore are an unknown mixture of 40 plus years of hatchery plantings and any previous residents.

The key question here is how do you produce anadromy.  Taking a mix of a large number (Table 12, (Aq. Bio. Asmt. Rpt.) local rainbow with no significant history of anadromy and mixing it with a hatchery stock of unknown anadromous tendencies seems to be an unlikely - or at least an unreliable way to maximize an anadromous population. 

Since upstream passage, as discussed above, is uncommon, even with complete project removal all that will happen will be a continued saturation of non-anadromous fish. This is not a strategy.

Performance Standards

When we started to think of how we could use the Kilarc facility to improve fish, we immediately came to the dilemma that we had no metrics - no way to judge if there was an improvement.  So we have proposed one.  This is in the documents section of this site as a Working paper KC-2, "Performance Measures for Recovery of Endangered Species Act-Protected Anadromous Fish"

  It suggests that we use the best science available to estimate how the habitat will improve in the bypass region if the hydropower flows were returned there.   Then, that becomes the standard we have to beat with our Alternative Plan : The reconstruction Alternative.

Acid Rain

If local CDFG biologists get credit for local fish restoration, and local NMFS staff get credit for local habitat creation by dam removal and restoration, then who is responsible for the larger consequences of their actions.  Removing this Green Power source will cause a fossil based replacement generation to poison our air and water.  The acid rain effects, global warming, and other process pollutants are killing our environment. Doing away with Green Power sources such as this project as is advocated by some means the incremental destruction of our environment.   Is this really what we want? 

It seems that no entity, CDFG, NMFS nor PG&E are willing to address the larger effects of their self-interested local actions.  Are not State and national concerns the purview of State and National agencies.  


Water Temperature

The target fish need cold water. Local people have shown KC data that the water coming from the Kilarc powerhouse is a lot colder than the water coming down the Old Cow. If water were returned to the Old Cow,  the resulting water would be warmer because it is exposed to the sun less, the hydropower energy is not removed, and it is warmed by the warm summer air. 

Also the Old Cow bypass waters are further warmed by water that gets washed off the fields.  In summary, water temperatures could be analyzed to find out how this effects downstream fish habitat.  Further as part of a development project we might help solve the field run-off problems. 


We are trying to find a partner interested in taking over some of the Kilarc site for recreation.  The County has shown little interest primarily as the result of heavy handed discussions by PG&E staff emphasizing how difficult it is to operate.  PG&E has also visited with California State Parks - again trying to convince the that they do not want to take over the site for recreation.  Why PG&E is so anti-recreaton and implicitly anti-Green Power is unknown.

          South Cow

Davis Hydro is not focusing on the South Cow at the present moment. 

The Kilarc project is quite likely to be successful in producing fish restoration so that Davis Hydro's primary focus to get the agencies to consider an alternative to PG&E's demolition plan.

Further, several other factors suggest starting with the Kilarc Project.

    For the moment There is less interest in the South Cow, because the forebay is a favorite fishing and recreation site.  There is no public fishing access on the South Cow.

    The South Cow is partially on the Tetrick ranch, which may be interested in operating the power plant, and may be interested in operating the facility.

    The Kilarc Canal has more stream-like area that is convertible to fish habitat.

    On the other hand, the field run-off is far more severe in the South Cow Valley therefore the opportunity for improvements are greater.

    Finally later, in a collaborative way, the Abbott Ditch may provide interesting habitat experiments that may generate a lot of fish at little cost to anyone. 


KC LLC has visited the Abbot and German Ditches to get an understanding of the problems and opportunities. 

These ditches are primary point sources of opportunity to help the fish in this area.   Ideas on cleaning screens, diversion maintenance, upstream fish passage and ditch maintenance were discussed.  Screens are expensive and have to be maintained.  By having the FERC mandate that a new Kilarc or South Cow Licensee be the steward of the ditch diversions, multiple benefits may result for all parties.