
Middle reach of Sonoma Creek immediately above Brush Creek confluence.
'Santa Rosa Creek' is a 22 mile (35 km) long
stream which rises on
Hood Mountain and discharges to the
Laguna de Santa Rosa in
Sonoma County, California.
[1]
Description
Though it begins as a wild stream in the
Mayacamas Mountains, Santa Rosa Creek is
culverted for part of its course through
the city of Santa Rosa's downtown. The
riparian area has a rich
prehistoric past with settlement of the Southern
Pomo people on much of the middle and lower reach banks. A significant stream restoration project was created in the downtown Santa Rosa reach in the late 1990s, allowing
steelhead and
coho salmon to migrate to productive upstream
spawning areas. Major tributaries to Santa Rosa Creek include
Brush Creek,
Piner Creek,
Matanzas Creek and Colgan Creek. Annual
precipitation in the Sonoma Creek
watershed ranges from about 60 to 70 centimeters per annum.
Water quality sampling in the Railroad Square area of Santa Rosa indicate
coliform bacteria standards are often exceeded.
[2]
History

Flat Rocks
boulder formation in the
confluence zone of Brush Creek into Santa Rosa Creek.
Archaeological data demonstrates the habitation of Pomo
tribes on the lower reaches of Santa Rosa Creek, while a branch of the
Yuki tribe lived near the
headwaters on the slopes of
Hood Mountain. In the vicinity of the confluence of
Brush Creek there is a noteworthy
rock formation known as "Flat Rocks"; adjacent was a native Pomo village, presumably to exploit the resources of the confluence area as a suitable place for
fishing, bathing, washing and providing
drinking water. Near this location in the year
1827, Padre Amoros
baptized a Pomo
maiden on the day of the
Feast of the Roses; that event created the name of this locale as "Santa Rosa". Hence the city of Santa Rosa really owes its name to the Santa Rosa Creek environment.
In the city of Santa Rosa, remains of the
Carrillo Adobe attest to
Spaniards as
settlers in the middle reaches of Santa Rosa Creek. As the city of Santa Rosa developed more intensively, political pressure arose in the 1960s to channelize much of the creek in the core area of the city. This action led to a greatly reduced capability for
anadromous fish to reach
spawning areas upstream. Consequently, by the 1990s, planning began for a creek restoration project to tear out much of the channel concrete lining, provide re-vegetation and create a new low flow channel to accommodate
steelhead and
coho salmon spawning runs to the middle and upper reaches (i.e. above the downtown area of the city of Santa Rosa).
Geology
The headwaters of Santa Rosa Creek rise on the northern slopes of Hood Mountain, where the soils at the headwaters consist of soils of the Goulding cobbly clay loam association, which are well-drained gently to very steep
loams and
clay-loams situated upon upland formations. The lower elevations of the Hood Mountain headwaters consist of the Boomer soil association, which group has well-drained loams over a clay-loam subsoil.
[3] Considering the steepness of much of the
terrain there is a remarkable lack of erosion, primarily because
human access has been historically low, and
vegetative cover has been kept intact.
As Santa Rosa Creek descends toward the valley floor Falta very gravelly loam is encountered, which has scrubby
Valley Oak cover. On the gentle rolling slopes that join the valley are Haire series moderately well-drained clay loam soils, which are used for dry-farm
pasture and some
vineyards. On the valley floor Santa Rosa Creek flows under
State Route 12 and runs along Melita Road, thence somewhat more northerly and parallels the south side of Route 12. Over this middle reach the soils are typical of alluvial fans, consisting of Yolo silt loams and clay loams of less than two percent slope. Historically this soil has served pasture uses with some orchards. Currently most of this area is developed with medium density residential uses.
Below the downtown confluence with
Matanzas Creek, which drains the northern slopes of
Sonoma Mountain, can be considered the lower reach of this watershed. Most of the soils extending some distance from Santa Rosa Creek are Yolo
sandy loam overwash. This zone is especially subject to
flooding, and historically has served as pasture,
orchard and vineyard. Erosion potential is slight due to the less than five percent slope of this reach.
Ecology
The upper reaches and headwaters of Santa Rosa Creek are on Hood Mountain on the western slopes of the southern
Mayacamas Mountains. Much of the
ecosystem of the headwaters is relatively dense mixed
oak woodland, which has a
canopy of
Coast live oak,
Douglas fir, California Buckeye (''
Aesculus californica'') and
Bigleaf Maple[4]. In these oak woodlands, the dominant
understory plants are
toyon,
blackberry,
western poison-oak and in occasional drier patches some
coyote brush. In some of the steeper, cooler
riparian zones there are a high concentration of California laurel. Common animals observed include
California Mule Deer,
gray squirrel,
raccoon,
skunk and
opossum. Less frequently
bobcat and
mountain lion are seen. There is abundant
birdlife including the
scrub jay,
Steller's jay,
acorn woodpecker and
junco.
As Santa Rosa Creek reaches the valley floor near Melita Road, the creek is choked with
Red willow, and also has
coast live oak,
Bigleaf maple,
California laurel as well as a few
Douglas fir and
Huckleberry Oak, ''Quercus vacciniifolia''. This middle reach of the creek has more of a suburban character compared to the wild headwaters area. The middle reach continues as a richly vegetated
riparian zone from Melita Road westerly to Farmers Lane. The reach at the confluence of
Brush Creek is particularly notable for the large boulder formation, known as "Flat Rocks". Below Farmers Lane the creek becomes channelized and much of the natural character is lost, until the creek begins to exit the west side of the city of Santa Rosa.
References
1. ''Santa Rosa Quadrangle'', Fifteen minute series, USGS Quadrangle Map, U.S. Government Printing Office, Washington DC (1958)
2. The Sonoma County Environmental Health Department water quality sampling data
3. ''Soil Survey, Sonoma County, California'', U.S. Department of Agriculture, Soil Conservation Service, Government Printing Office, Washington DC, May 1972
4. ''Ecology of the southern Mayacmas Range'', Lumina Technologies, Santa Rosa, Ca., May 11, 2005
See also
★
Anadromous
★
Annadel State Park
★
Carrillo Adobe
★
Hood Mountain
External links
★
Santa Rosa Creek Restoration Project of the City of Santa Rosa