Wednesday, November 20, 2013

Reclaimed Water for the Win?

Looks like a nice little meandering river, no? Nice riparian vegetation- loads of willows, cottonwoods, sycamores- good flow for a southern Californian stream deep into the fall before any rains have commenced. Surely such an inviting scene is miles away from the machinations of modern man. But that little road way may tip you off otherwise...

What you are looking at is a section of Conejo creek downstream from the Hill Canyon Wastewater Treatment Plant of Thousand Oaks. Of course I have mentioned this watershed before. Conejo creek has received some press recently due to the revelation that the federally protected southern steelhead has begun to recolonize these waters. The cities of Thousand Oaks and Camarillo both discharge treated wastewater into the creek. And in light of the fish's presence in the creek both municipalities may now be required to sustain these discharges in order to maintain the habitat. And this is much to the ire of at least Camarillo, because that city had begun construction of a pipeline to use their reclaimed water for agriculture (probably sod farms as I don't think reclaimed water can be used for food crops).

And this whole debate is one which we have visited upon before: In a landscape that has historically been robbed of water flow through dams and diversions, is it now our obligation to recoup some of the  losses by taking advantage of outflow from wastewater treatment plants? I know it is not a pleasant thought, concentrating wildlife restoration efforts in essentially treated sewage. But as I said before, in a water parched landscape, beggars can't be choosers. And ultimately, it is not our choice to make- wildlife is already making the choice to live in habitats made possible through reclaimed water discharge- such as the steelhead recolonizing Conejo creek or the waterfowl I photographed in some of the tanks for the treatment facility in the picture below.

And I mean, it really is a nice looking stream when you get over the "treated sewage" aspect of it...

Of course all of this talk of treated effluent begs the question: should we concentrate beaver restoration in these areas in southern California? Well I would say YES! YES!! and more YES!!!

But let me buffer my argument more with this line of reasoning. To reestablish beaver they need to get over the predator hump. MartinezBeavers talked about this issue recently here. While beaver have been extirpated from many parts of their former range, their natural predators-cougars, bobcats, coyotes, bears, wolves- have done quite nicely in the meantime. Jeff Baldwin of Sonoma State addresses this very real issue of the problem of beaver reintroduction in predator saturated lands. It becomes less to do with stream slope gradient/vegetation type and more to do with how will this beaver transplant survive in small streams before it can build dams to survive predation? There is a real potential for loss in restoration efforts especially in arid lands with small streams and abundant predators. So the real question becomes how do we maximize our chances of successfully reintroducing beaver into these lands? Well we need to look at beaver restoration as essentially a war- there will be heavy casualties beavers will absorb, no doubt about it, from people and predators.

Okinawa beachhead. 1945. wiki
But if we utilize the areas of deepest water and highest flow- often man made reservoirs, dams, and water reclamation outflows- we will stand the greatest chance of establishing beachheads. And from these beachheads beaver can then spread across the whole watershed.

N. Matijilla Creek. Los Padres Wilderness

Middle Lions Camp. Sespe Wilderness
Above are two places I would love to see beaver reintroduced. The north fork of Matijilla creek is a tributary of the Ventura river and still has steelhead while Middle Lions camp also has a stream in it with steelhead. In the case of Lions camp I have it on good record that an acquaintance of mine, Tim Peddicord a retired biology teacher, spotted a beaver there in the 1960's. Additionally numerous other anecdotal reports of beaver in the Sespe watershed suggest that this area was a final stronghold for beaver in southern California.

However the Sespe wilds might not be the ideal spot to reintroduce beaver initially, as appealing as it may seem. That name, Lions camp, is no joke- there are lots of cougars out there, and bear, and coyote, and bobcat. The flows might be low or the pools just not deep enough to establish beaver in high enough densities to get over the predator hump out in the Sespe.

But how about a place like this:

Santa Clara River Estuary
Although the lower Santa Clara river runs dry due to the Freeman Diversion the estuary forms a veritable lake due to discharge from the Ventura wastewater treatment plant. Dense beds of tules and acres of willow thickets would be ideal forage. No cougars or bears here. Establishing a viable population would be possible and from here intrepid beavers could spread up into the entire watershed or be transplanted by humans to other areas in the watershed.

We just have to get over the "icky" reaction to treated wastewater- the wildlife already has.

Conejo Creek
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