Environment

Cotati Creek Critters current project site is a 1-mile reach of the main channel of the Laguna de Santa Rosa in Cotati and part of Rohnert Park – NOT Cotati Creek, which is a smaller tributary that flows into the Laguna channel from the west, under Old Redwood Highway close to downtown Cotati, and joins the Laguna de Santa Rosa near Marsh Way, just south of East Cotati Avenue.

The dotted line on the map above indicates the extent of the Cotati Creek Critters project site.

A watershed is an area of land that drains to a common creek, stream, or river.

The Laguna de Santa Rosa watershed covers a 250 square mile area. The Laguna waterway is the largest tributary to the Russian River. It runs northwest from Cotati/Rohnert Park to enter the Russian River north of Forestville. The Laguna watershed is made up of smaller watersheds - creeks such as Windsor Creek, Mark West Creek, Santa Rosa Creek, and Copeland Creek flow into the Laguna. The Laguna watershed in turn exists within the 1,485 square mile Russian River watershed.

Originally the Laguna was a vast mosaic of vernal pools, lakes, marshes, woodlands and grasslands. Many of the watercourses have been straightened or have filled with sediment, and many of the marshes and wetlands have been built on or drained for agriculture. Many species of birds, fish, mammals, and plants that used to be abundant have disappeared along with their diminishing habitat. As the areas of existing wetlands and waterways shrink, what is left becomes ever more valuable. The wetlands of the Laguna that remain act as a biological filter for water, provide storage capacity for floodwaters, provide valuable wildlife habitat, and important recreational opportunities for people.

Most of Cotati's creek channels have been channelized and the banks either denuded or overgrown with invasive species such as blackberry. The Cotati Creek Critters, working with the support of the Laguna de Santa Rosa Foundation, the City of Cotati and the Sonoma County Water Agency (SCWA), has been sponsoring volunteer creek restoration efforts since 1998, particularly since receiving an Urban Streams Restoration Grant from the California Department of Water Resources in 2005. This has allowed us to plant and maintain well over 1,600 native trees and shrubs along the Laguna in Cotati.

Cotati Creek Critters has planted approximately a mile of native trees alongside the Laguna de Santa Rosa channel in Cotati and a section of Rohnert Park.

The Sonoma County Water Agency, which has jurisdiction over most of the creek channels in the area, balances responsibility for flood control with support of ecological values such as enhancing wildlife habitat. The banks of the Laguna channel in Cotati used to be mown once or twice a year. The resulting combination of water and sunlight in the creek channels created the perfect environment for water- and sun-loving plants, such as cattails and in some areas Himalayan blackberries, which filled the channel from side to side. The build up of vegetation in the channel caused concern from a flood control standpoint. The lack of shade also caused water temperatures to rise. Warm water temperatures are a major cause of the decline of salmonid species downstream in the system. The Water Agency periodically mechanically removed sediment from the channels to reduce risks of flooding and maintain flood water capacity.

By growing trees, in the long-term the trees will shade out the vegetation in the channel, helping to keep water cool.

Other measures are being taken to balance ecological and flood control needs. For example when the trees reach a certain height, the lower branches are trimmed to avoid the collection of storm debris in the channel. The plantings are in straight lines (rather than in more natural “clumps,”) to reduce obstruction for water flowing in the channel.

A. Native species such as Valley Oak, California Buckeye, Big Leaf Maple, Box Elder, California Rose, Blue Elderberry, and Snowberry are ideally adapted to our unique environment, in which they and their ancestors have grown for thousands of years. They provide just the right kinds of food and shelter for the native birds, insects and mammals with which they have coevolved, mutually adapting to each others' needs.

Invasive species such as Himalayan blackberry, pampas grass, broom and periwinkle (vinca) have been introduced from other ecosystems and can outcompete native plants to the point of excluding them completely. They do not support the same diversity of wildlife as native plants do.

By selectively removing invasive exotics and replanting with natives we enhance the sources of food and shelter for wildlife.

Now that we have completed the planting of a mile of native trees and shrubs, Cotati Creek Critters is focusing on the planting of an understory of native grasses, sedges, and rushes. Here are some of the reasons why.

Non-native annual grasses have shallow roots that die with the plant, leaving the soil vulnerable to erosion, particularly during high water flows. During the growing season, grasses such as wild oats (Avena spp.) can grow to 5 ft. tall, then turn brown and dry during the summer, creating a fire hazard.

There is much more to learn about native California grasses and grasslands. There are links to two informative articles at this website under Media.

The Laguna de Santa Rosa is home to a wide variety of plants and animals. Click on the thumbnails below for larger images of some of these plants and animals, or click here to see a list of observed bird species.

Birds Seen Around the Laguna in Cotati (provided by John A. Dell'Osso)

Browse our cumulative bird list below, or view a list of birds seen at specific outings and educational field trips in pdf format:

Bird list (last updated June 2010) (pdf)
Read the related article Bird Monitoring, by John Dell'Osso (pdf)

* = nesting species; w = winter resident

Black-crowned night heron
Green-backed heron
Snowy egret (w)
Great egret
Great blue heron
Mallard (*)
Killdeer
Long-billed curlew (w)
Common snipe (w)
Western gull
Ring-billed gull
California quail
Ring-necked pheasant
Turkey vulture
Black-shouldered kite
Red-shouldered hawk
Cooper’s hawk
Sharp-shinned hawk
Red-tailed hawk
Osprey
American kestrel
Merlin (w '03)
Rock dove (Pigeon) (*)
Barn owl
Anna’s hummingbird
Allen’s hummingbird
Belted kingfisher
Northern flicker (red-shafted)
Nuttall’s woodpecker
Hairy woodpecker
Western kingbird (*)
Say’s phoebe
Black phoebe

Cliff swallow (*)
Barn swallow
Western scrub jay
American crow (*)
Raven
Chestnut-backed chickadee
Bushtit
Western bluebird
American robin
Northern shrike (*) (extirpated since 1989)
Mockingbird (*)
Water pipit (w)
Cedar waxwing
European starling (*)
Yellow-rumped warbler (w) (ssp. Audubon’s)
Black-throated gray warbler
Common yellowthroat
California towhee
Dark-eyed junco (subspecies Oregon and Slate-colored (w))
Red-winged blackbird
Brewer’s blackbird
Northern oriole (Bullock’s) (*)
Hooded oriole (December 1998 only)
White-crowned sparrow (w)
Golden-crowned sparrow (w)
American goldfinch
Lesser goldfinch (*)
House finch
European house sparrow (*)

Plant List for Revegetation of the Cotati Reach of the Laguna
The plants we have been planting along the Laguna are divided evenly between trees and shrubs/herbaceous plants. Below are the two groups. All these species are native to riparian plant communities of Sonoma County. It is probably a broader assemblage then what would have been present historically in Cotati. We’ve chosen to include as many different species as reasonable to maximize diversity for both wildlife habitat and human enjoyment. Many of these species, and about 150 total plants, have already become successfully established at our Helen Putnam site over the last several years. Many of these plants are great in a home or commercial landscape as well, and we can recommend a particular species depending on your needs. If you have any questions, contact Stewardship Coordinator Wade Belew.