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Cotati Creek Critters Project Site ~ The Laguna de Santa Rosa ~ Why Plant Trees? ~ What About Flood Control? ~ Native and Invasive Plants ~ Why Plant Native Grasses? ~ Flora & Fauna ~ Revegetation Plant List

Cotati Creek Critters project sites

Cotati Creek Critters had two restoration project sites along the Laguna de Santa Rosa channel in Cotati.

  • 1 mile of the main channel of the Laguna de Santa Rosa in Cotati and part of Rohnert Park, from Liman Way to the bicycle/pedestrian bridge north of E. Cotati Ave.

Note: Our name is confusing. The site doesn’t include Cotati Creek, which is a smaller tributary that flows into the Laguna channel from the west, under Old Redwood Highway close to downtown Cotati, to join the Laguna de Santa Rosa channel near Marsh Way, just south of East Cotati Avenue.

  • Further downstream, on the west bank of the Laguna channel, from Gravenstein Way to Commerce Blvd.

For further details and maps showing the locations of the two sites, see the Creek Stewardship Days page.

The Laguna de Santa Rosa

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 2,000 native trees and shrubs along the Laguna in Cotati.  Since then hundreds of understory plants – native grasses, sedges, and rushes - have been planted as well.


The video above is a presentation on the Laguna de Santa Rosa: Past, Present and Future, by Denise Cadman, given in Cotati on January 12, 2012.


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Why Plant Trees?

Cotati Creek Critters planted approximately a mile of native trees and shrubs alongside the Laguna de Santa Rosa channel in Cotati and a section of Rohnert Park, and then another 350 at a second site further downstream, 2011-2012.

The benefits of planting trees include:

  • The trees will eventually form a leafy canopy over the channel, creating shade, which will discourage non-native plants such as Himalayan Blackberry and tall, invasive grasses that slow stormwater flows and trap debris.
  • Shade helps keep water cool, which is beneficial for aquatic life including salmonids downstream in the system.
  • Lower water temperatures keep bacteria levels low, which is important for clean drinking water and recreational uses downstream. The Russian River resort areas of Rio Nido, Guerneville and Monte Rio are on the receiving end of our stormwater runoff.
  • Tree roots will help to stabilize banks and prevent soil erosion, which causes sedimentation downstream in the Laguna. Sediment is considered a significant form of pollution.
  • Trees provide shelter, food and nesting sites for birds, beneficial insects, and other wildlife.
  • Healthy creeks and trees help to make Cotati a more beautiful and enjoyable place to be, improving our quality of life and providing valuable educational opportunities.

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What about flood control?

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.

For further information on the Sonoma County Water Agency’s stream maintenance policies see http://www.scwa.ca.gov/stream-maintenance-program/ and CommunityVoice:_SCWA Will Continue Cotati Creek Critters Work In Laguna (pdf).

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Native and Invasive Plants...

Q. What are "native" and "invasive" species and why does it matter?

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.

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Why Plant Native Grasses?

After planting native trees and shrubs along a 1-mile section of the Laguna channel, Cotati Creek Critters planted hundreds of understory plants - native grasses, sedges, and rushes. Here are some of the reasons why.


A few facts:

  • Most of the grasses we see around us are non-native annual grasses, introduced from Europe and other Mediterranean climatic regions during the past 200 years or so. (Annual grasses grow for a year or less, set seed, and die).
  • There are over 300 species of native grasses in California, most of which are perennial (meaning that they grow for more than a year).
  • Unlike non-native annual grasses, some native perennial bunch grasses can live for over 100 years.
  • 98% of California's native grasslands no longer exist, mainly due to usurpation by non-native species, conversion to agriculture, and urban development.

Understory plants in the nursery, ready to go ->

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.

In contrast, native grasses have many beneficial characteristics.

click image for full sized diagram!

Root systems

Native perennial grasses are adapted to summer drought, with long roots which penetrate deep into the soil. This is important because:

  • They stabilize creek banks and reduce soil erosion.
  • They enable water and nutrients to infiltrate deep into the soil.
  • Approximately 1/3 of the root systems die each year, adding organic matter deep into the soil profile.

Growth Habit

  • Because the grasses grow in tufts or bunches rather than as a continuous layer of turf, spaces and tunnels are created between them which can allow small animals to find their way amongst them, and wildflower seeds, acorns etc. to fall into the gaps and take root, enhancing biodiversity.
  • On a larger scale, native grasslands support a wide variety of wildlife, from birds to foraging mammals. All grass seed is edible and is an important food source for many types of wildlife.
  • The species we are planting here in Cotati mainly grow 1 1/2 ft. to 2 ft. tall, so once established they will require minimal mowing.

Basket sedge, carex barbarae.
The long, horizontal roots of the sedge plant are a traditional basket-making material, now also used in riparian restoration projects.

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

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Changes Over Time

Click on the thumbnails below for maps and photos of the area over time.

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Flora and Fauna of the Laguna in Cotati

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.

(photos by Wade Belew unless otherwise noted)

Elder Flower

Elder Berries

Box Elder





(photo by Don Jackson)

Mallard Pair
(photo by Anne Leonard)

Ring-Necked Pheasant
(photo by Anne Leonard)

American Robin
(photo by John Dell'Osso)

Anna's Hummingbird
(photo by John Dell'Osso)

Cedar Waxwing
and Persimmon

(photo by John Dell'Osso)

Oak Titmouse
(photo by John Dell'Osso)

Red Shouldered

(photo by John Dell'Osso)

Anna's Hummingbird

(photo by John Dell'Osso)

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

John Dell'Osso, Cotati resident, and Chief of Interpretation at Point Reyes National Seashore, provided a cumulative list of birds he had observed along the Laguna channel in Cotati prior to 2008.  From 2008-March 2013 he continued to update this list on a regular basis.  The following is the complete cumulative list up until March 2013.

For details of sightings see:

Bird list (covers all of 2008 through 2010) (pdf)
Bird list(January 2011 through December 2012) (pdf)
Bird list(February 2013 through March 2013) (pdf) and read the related article Bird Monitoring, by John Dell'Osso

White pelican
Black-crowned night heron
Green-backed heron
Snowy egret (w)
Great egret
Virginia rail
Great blue heron
Mallard (*)
Canada goose
Common merganser
Long-billed curlew (w)
Common snipe (w)
Western gull
Ring-billed gull
California quail
Ring-necked pheasant
Wild turkey
Turkey vulture
Black-shouldered kite
Red-shouldered hawk
Cooper’s hawk
Sharp-shinned hawk
Red-tailed hawk
American kestrel
Merlin (w '03)
Peregine falcon
Rock dove (Pigeon) (*)
Eurasian collared dove
Mourning dove
Barn owl
Anna’s hummingbird
Allen’s hummingbird
Belted kingfisher
Northern flicker (red-shafted)
Red-breasted sapsucker
Downy woodpecker
Nuttall’s woodpecker
Hairy woodpecker
Western kingbird (*)
Say’s phoebe
Black phoebe

Cliff swallow (*)
Violet-green swallow
Barn swallow
Western scrub jay
American crow (*)
Oak titmouse
Chestnut-backed chickadee
Brown creeper
Red-breasted nuthatch
Marsh wren
Ruby-crowned kinglet
Western bluebird
American robin
Hermit thrush
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
Song sparrow
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
Pine siskin
European house sparrow (*)

* = nesting species; w = winter resident


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COTATI CREEK CRITTERS: PLANT SPECIES LIST – updated in retrospect, Feb. 18, 2016

Plantings included equal numbers of trees and shrubs/herbaceous plants, all species native to riparian plant communities of Sonoma County. It is probably a broader assemblage than would have been present historically in Cotati. As many different species as reasonable were included to maximize diversity for wildlife habitat and human enjoyment. Understory plants, mainly native grasses, sedges and rushes, were added after trees and shrubs had become established.

Big leaf maple - Acer macrophyllium
Black oak – Querucs kelloggii
Black walnut - Juglans californica
Blue elderberry - Sambucus mexicana
California bay - Umbellularia californica
California buckeye - Aesculus californica
Coast live oak - Quercus agrifolia (grows naturally here, many “volunteers”)
Fremont cottonwood - Populus fremontii
Oregon ash - Fraxinus latifolia
Red alder - Alnus rubra
Red willow - Salix lutea
Yellow willow - Salix lutea
Valley oak - Quercus lobate
Western sycamore – Plantanus racemosa

Blue elderberry - Sambucus mexicana
Box elder - Acer negundo
California blackberry - Rubus ursinus (contrast with invasive Himalayan)
California wild rose – Rosa californica (terribly invasive)
Coffeeberry - Rhamnus californica
Coyote bush - Baccharis pilularis (thrives and spreads naturally here; re-emerged when not mown)
Golden currant – Ribes aureum
Hawthorn - Crataegus suksdorfii
Mulefat - Baccharis salicifolia
Ninebark - Physocarpus capitatus
Pink flowering currant - Ribes sanguineum
Redtwig dogwood - Cornus sericea
Snowberry - Symphoricarpos albus
Spice bush - Calycanthus occidentalis
Toyon - Heteromeles arbutifolia
Twinberry - Lonicera involucrata

Basket sedge - Carex barbarae
California fescue – Festuca californica
Clematis Common rush - Juncus effusus
Gray rush - Juncus patens
Green rush - Juncus effusus
Wild grape
Woodland strawberry


TOP MOST INVASIVE,NON-NATIVE PLANTS of this area (i.e. that are a problem in the CCC project area of the upper Laguna de Santa Rosa):

English ivy
Harding grass
Himalayan blackberry (contrast with native Ca. blackberry)
Pampas grass
Periwinkle (vinca major)
Scotch broom (distinguish from/contrast with coyote bush as they can look similar when no flowers)
As of 2016: Privet

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Updated 2013 by Lucy Kenyon