The Laguna de Santa Rosa is a

wetland A wetland is a distinct ecosystem that is flooded or saturated by water, either permanently (for years or decades) or seasonally (for weeks or months). Flooding results in oxygen-free (anoxic) processes prevailing, especially in the soils. The p ...

complex that drains a watershed encompassing most of the Santa Rosa Plain in Sonoma County, California, United States. The California Office of Environmental Health Hazard Assessment has issued a safe eating advisory for any fish caught in Laguna de Santa Rosa due to elevated levels of mercury and

PCBs Polychlorinated biphenyls (PCBs) are highly carcinogenic chemical compounds, formerly used in industrial and consumer products, whose production was banned in the United States by the Toxic Substances Control Act in 1979 and internationally by t ...

. In addition, there is a notice of "do not eat" for

black bass Black is a color which results from the absence or complete absorption of visible light. It is an achromatic color, without hue, like white and grey. It is often used symbolically or figuratively to represent darkness. Black and white have o ...

Description

The Laguna, whose principal tributary streams rise on the southern slopes of the Sonoma and

Mayacamas Mountains The Mayacamas Mountains are located in northwestern California in the United States. The mountain range is part of the Northern Inner Coast Ranges, of the California Coast Ranges System. Geography The Mayacamas Mountains are located south of the ...

,''Santa Rosa Quadrangle'', Fifteen minute series,

USGS The United States Geological Survey (USGS), formerly simply known as the Geological Survey, is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, a ...

Quadrangle Map, U.S. Government Printing Office, Washington, D.C. (1958) is the largest

tributary A tributary, or affluent, is a stream or river that flows into a larger stream or main stem (or parent) river or a lake. A tributary does not flow directly into a sea or ocean. Tributaries and the main stem river drain the surrounding drai ...

Mark West Creek Mark West Creek is a U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map, accessed March 9, 2011 stream that rises in the Mayacamas Mountains of Sonoma County, California, United States. Tributaries ...

. The sinuous watercourse and associated wetlands form a significant floodplain during the heavy winter rains, capable of storing over of stormwater. Beyond its

hydrological Hydrology () is the scientific study of the movement, distribution, and management of water on Earth and other planets, including the water cycle, water resources, and environmental watershed sustainability. A practitioner of hydrology is calle ...

significance, the Laguna is Sonoma County's richest area of

wildlife Wildlife refers to undomesticated animal species, but has come to include all organisms that grow or live wild in an area without being introduced by humans. Wildlife was also synonymous to game: those birds and mammals that were hunted ...

habitat In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...

, and the most

biologically diverse Biodiversity or biological diversity is the variety and variability of life on Earth. Biodiversity is a measure of variation at the genetic (''genetic variability''), species ('' species diversity''), and ecosystem ('' ecosystem diversity'') ...

part of the county, having been called a "national treasure" for its

ecological Ecology () is the study of the relationships between living organisms, including humans, and their physical environment. Ecology considers organisms at the individual, population, community, ecosystem, and biosphere level. Ecology overlaps wi ...

wealth. A number of rare and endangered species occur in the Laguna, including federally listed

threatened Threatened species are any species (including animals, plants and fungi) which are vulnerable to endangerment in the near future. Species that are threatened are sometimes characterised by the population dynamics measure of ''critical depensa ...

and

endangered An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and in ...

anadromous salmonid species and three endangered plants that are

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found else ...

here. From about 1870 to 1990

water quality Water quality refers to the chemical, physical, and biological characteristics of water based on the standards of its usage. It is most frequently used by reference to a set of standards against which compliance, generally achieved through tr ...

and biota deteriorated in the Laguna, due to intensification of urban development and associated agricultural encroachment into the floodplain. In the 1990s the trend began to reverse, but the watercourse is still listed as impaired under the federal Clean Water Act for

sediment Sediment is a naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of wind, water, or ice or by the force of gravity acting on the particles. For example, sa ...

nitrogen Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at se ...

phosphorus Phosphorus is a chemical element with the symbol P and atomic number 15. Elemental phosphorus exists in two major forms, white phosphorus and red phosphorus, but because it is highly reactive, phosphorus is never found as a free element on Ear ...

temperature Temperature is a physical quantity that expresses quantitatively the perceptions of hotness and coldness. Temperature is measurement, measured with a thermometer. Thermometers are calibrated in various Conversion of units of temperature, temp ...

, mercury, and

dissolved oxygen Oxygen saturation (symbol SO2) is a relative measure of the concentration of oxygen that is dissolved or carried in a given medium as a proportion of the maximal concentration that can be dissolved in that medium at the given temperature. It ca ...

, rendering it the most impaired water body on the North Coast of California. Notwithstanding the large historical reduction in resource extent, the Laguna de Santa Rosa is presently the second-largest freshwater

in coastal Northern California and still habitat to over 200

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

bird Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweig ...

and

salmon Salmon () is the common name for several commercially important species of euryhaline ray-finned fish from the family Salmonidae, which are native to tributaries of the North Atlantic (genus ''Salmo'') and North Pacific (genus '' Oncorhy ...

id species,

bald Hair loss, also known as alopecia or baldness, refers to a loss of hair from part of the head or body. Typically at least the head is involved. The severity of hair loss can vary from a small area to the entire body. Inflammation or scarrin ...

and

golden eagle The golden eagle (''Aquila chrysaetos'') is a bird of prey living in the Northern Hemisphere. It is the most widely distributed species of eagle. Like all eagles, it belongs to the family Accipitridae. They are one of the best-known birds of ...

osprey The osprey (''Pandion haliaetus''), , also called sea hawk, river hawk, and fish hawk, is a diurnal, fish-eating bird of prey with a cosmopolitan range. It is a large raptor reaching more than in length and across the wings. It is brown o ...

mountain lion The cougar (''Puma concolor'') is a large cat native to the Americas. Its range spans from the Canadian Yukon to the southern Andes in South America and is the most widespread of any large wild terrestrial mammal in the Western Hemisphere. ...

, river otter, coyote, bobcat, mink, and

gray fox The gray fox (''Urocyon cinereoargenteus''), or grey fox, is an omnivorous mammal of the family Canidae, widespread throughout North America and Central America. This species and its only congener, the diminutive island fox (''Urocyon littor ...

. While the Laguna has been heavily impacted by human activities in its watershed over the past century, in recent years a movement has grown to preserve and restore it both for ecological functions such as

values and

flood control Flood control methods are used to reduce or prevent the detrimental effects of flood waters."Flood Control", MSN Encarta, 2008 (see below: Further reading). Flood relief methods are used to reduce the effects of flood waters or high water level ...

capacity, and for outdoor recreation,

education Education is a purposeful activity directed at achieving certain aims, such as transmitting knowledge or fostering skills and character traits. These aims may include the development of understanding, rationality, kindness, and honesty ...

, and

research Research is " creative and systematic work undertaken to increase the stock of knowledge". It involves the collection, organization and analysis of evidence to increase understanding of a topic, characterized by a particular attentiveness ...

. The nonprofit Laguna de Santa Rosa Foundation, founded in 1989, has professionalized and expanded the scope of its programs since 2002, spearheading efforts to protect, restore, and create opportunities for the public to enjoy and learn in the Laguna.

Course

The principal source of the Laguna de Santa Rosa lies in the hills on the east side of U.S. Route 101 near

Cotati, California Cotati (; Miwok: ''Kota’ti'') is an incorporated city in Sonoma County, California, United States, located approximately north of San Francisco in the 101 corridor between Rohnert Park and Petaluma. Cotati's population as of the 2020 Censu ...

. Its waters descend to the west, crossing under U.S. Route 101 and into Cotati at the West Sierra Avenue interchange. It flows under the Old Redwood Highway just south of Charles Street and joins with a drainage channel near the end of Marsh Way. (Some sources consider this channel to be the main Laguna de Santa Rosa.) From this confluence, the Laguna turns to the northwest and crosses under East Cotati Avenue, providing portions of the boundary between Cotati and Rohnert Park. It crosses back under U.S. Route 101 near Southwest Boulevard and leaves Cotati, continuing northwestward through a series of confluences, with Copeland Creek,

Washoe Creek Washoe Creek is a perennial stream located in Sonoma County, California. It is about long and discharges to the Laguna de Santa Rosa. Washoe Creek rises in the low lying Meacham Hills southwest of the city of Cotati. It descends to the northea ...

, Hinebaugh Creek, and

Five Creek Five Creek is a westward flowing stream that rises in the city of Rohnert Park, California, United States and discharges to the Laguna de Santa Rosa. The creek is channelized as it flows through the city and runs in an artificially rectilinear fas ...

. It crosses Llano Road near the regional water treatment plant, then crosses Todd Road and joins Blucher Creek. East of

Sebastopol Sevastopol (; uk, Севасто́поль, Sevastópolʹ, ; gkm, Σεβαστούπολις, Sevastoúpolis, ; crh, Акъя́р, Aqyár, ), sometimes written Sebastopol, is the largest city in Crimea, and a major port on the Black Sea ...

, it crosses under State Route 12 at milepost 9.63 and turns to the north. Just south of Guerneville Road, the Santa Rosa Flood Control Channel enters the Laguna, bring water from Santa Rosa Creek and its tributaries. The Laguna continues north, emptying into

amidst the wetlands east of Forestville.

History

Archaeological data in southern Sonoma County indicates the land surrounding the Laguna de Santa Rosa was under the control of three Pomo tribelets which together, controlled about . These Pomo peoples were called the Konhomtara, the Kataictemi, and the Bitakomtara, whose languages were mutually unintelligible. The Konhomtara’s territory included "…the area of present day Sebastopol, bounded on the east by the Laguna, on the north by the Russian River, on the west by the summit of the mountains nearest the coast, and on the south by an indeterminate line that extended from the south end of the Laguna to the western border (Stewart, 1943)". The Kataictemi held the land on both sides of the Russian River north of Mark West Creek. Their northern border was about two miles (3 km) north of present-day Healdsburg, and included the lower portion of Dry Creek. The Bitakomtara may have been two tribelets, with one located at the head of Santa Rosa Creek, and the other located in Santa Rosa, the latter holding the eastern Laguna lands. Bitakomtara territory occupied the land that was bordered on the north by Mark West Creek, on the West by the Laguna, on the south by "an indefinite line that ran from the top of Sonoma Mountain to the South end of the Laguna" and on the east by the summit of the Mayacamas Mountains southward to the peak of Sonoma Mountain (located adjacent to Rohnert Park). The "South end of the Laguna" was and is as far south as the town of Cotati, approximately south of Rohnert Park. Supporting the claim that these three Pomo tribelets were the occupants of the territory is the fact that there are over 80 archaeological sites that have been identified within the Laguna's historic marshlands as being Pomo. Some of the sites are on the floodplains on the western margin of the Laguna. The rich wetlands of the Laguna were an important resource for the Pomo people. Control of these resources created a reported tension between the three Pomo tribelets themselves, and territorial borders appear to have been strictly enforced. Permission was needed to pass through each tribelet's territory. If, for example, the Konhomtara wished to fish on the Russian River, they had to gain permission from the Kataictemi. (Note: The above paragraphs are based on the work of David A. Fredrickson, Ph.D. and Daniel W. Markwyn, Ph.D.) The ancient Laguna of 2000 BC supported these tribes with abundant fish, fowl and tule reeds for constructing homes and

canoe A canoe is a lightweight narrow water vessel, typically pointed at both ends and open on top, propelled by one or more seated or kneeling paddlers facing the direction of travel and using a single-bladed paddle. In British English, the ter ...

s. In 1833, the original Mexican

land grant A land grant is a gift of real estate—land or its use privileges—made by a government or other authority as an incentive, means of enabling works, or as a reward for services to an individual, especially in return for military service. Grants ...

occurred that involved lands of the Laguna watershed. In the year 1870, the

railroad Rail transport (also known as train transport) is a means of transport that transfers passengers and goods on wheeled vehicles running on rails, which are incorporated in tracks. In contrast to road transport, where the vehicles run on a pre ...

arrived with associated channelizations and intensification of agricultural uses. By the 1960s, encroachment of the vast eastern plain was almost complete, and the previously rich run of 1.6 million anadromous fish had virtually collapsed. By 1989 over 92 percent of the Laguna's historic

riparian A riparian zone or riparian area is the interface between land and a river or stream. Riparian is also the proper nomenclature for one of the terrestrial biomes of the Earth. Plant habitats and communities along the river margins and banks a ...

habitat had been lost, and its water quality had reached critically poor levels. Historically the Laguna was the receiving waters for untreated (and later treated) sewage from adjacent cities, which eventually joined to participate in a regional sanitation district under the management of the city of Santa Rosa; to some degree due to regulatory action, litigation and pressure from local advocates, the City has become a partner in Laguna restoration by improving the treatment level of this wastewater and minimizing discharge through tertiary wastewater irrigation reuse for hay farming. Though concerns remain relating to compliance and management of this system, Santa Rosa's wastewater treatment and management system is considered to be one of the most progressive in the nation. In that year the Laguna de Santa Rosa Foundation was formed to mobilize public and private resources for preservation and restoration of this natural area. The Foundation has developed education programs, implemented a number of hydrological and ecological restoration projects, and published ''Enhancing and Caring for the Laguna'', a restoration and management plan for the Laguna watershed, in 2006. Primarily funded by the California Coastal Conservancy and developed with participation by hundreds of Laguna stakeholder organizations and individuals, the plan serves as a framework for improvement of the Laguna's

functions and development of

trail A trail, also known as a path or track, is an unpaved lane or small road usually passing through a natural area. In the United Kingdom and the Republic of Ireland, a path or footpath is the preferred term for a pedestrian or hiking trail. ...

access. The Foundation is now in the process of designing, funding and implementing projects to meet the goals of this plan.

Geology

As recently as the

Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...

period, this entire region was submerged below the

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the contin ...

. Around 12 million years ago, processes of uplift and

volcanic A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. On Earth, volcanoes are most often found where tectonic plates a ...

action formed the Mayacamas and Sonoma Mountains to the east and established the main

geomorphic Geomorphology (from Ancient Greek: , ', "earth"; , ', "form"; and , ', "study") is the scientific study of the origin and evolution of topographic and bathymetric features created by physical, chemical or biological processes operating at or ...

features of the present day landscape. Millions of years of stream erosion carving these mountains led to the rich soils of the Santa Rosa Plain and the Laguna de Santa Rosa drainage that meandered on the vast plain. The western hills are much less pronounced in elevation, and contribute far less to the drainage area of the basin. Soil types within the Laguna are quite complex and vary by reach. Many of the soils of the immediate Laguna area are classified as Clear Lake

clay Clay is a type of fine-grained natural soil material containing clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4). Clays develop plasticity when wet, due to a molecular film of water surrounding the clay par ...

; these soils are associated with regions of poor drainage, and are underlain by

alluvium Alluvium (from Latin ''alluvius'', from ''alluere'' 'to wash against') is loose clay, silt, sand, or gravel that has been deposited by running water in a stream bed, on a floodplain, in an alluvial fan or beach, or in similar settings. ...

and

sedimentary rock Sedimentary rocks are types of rock that are formed by the accumulation or deposition of mineral or organic particles at Earth's surface, followed by cementation. Sedimentation is the collective name for processes that cause these particles ...

. The surface of these soils is typically dark gray, and soils acidity ranges from slight to medium for the first 39 inches (100 cm) of depth; underlying this upper soil layer is a moderately alkaline dark gray clay. Deeper, typically below 46 inches (117 cm), is a gray and light brownish gray moderately alkaline clay. Wright loams are also present within the Laguna. The slope of the drainage basin is typically zero to two percent.

Hydrology and water quality

The Laguna de Santa Rosa is a principal tributary of

. Largest among the many tributaries of the Laguna are Santa Rosa Creek, Copeland Creek, Hinebaugh Creek,

and Blucher Creek. The Laguna consists of a winding ribbon of flow in the dry summer season and a massive floodplain that resembles a series of lakes in the winter storm season. There are numerous

vernal pool Vernal pools, also called vernal ponds or ephemeral pools, are seasonal pools of water that provide habitat for distinctive plants and animals. They are considered to be a distinctive type of wetland usually devoid of fish, and thus allow the safe ...

s on the floodplain that extend for miles to the east, which support many rare and endangered species. With regard to water quality, the Laguna de Santa Rosa is listed as Impaired under the federal Clean Water Act for

, mercury, and

, its six such listings being the most of any water body on the North Coast of California.

Ecology

The Laguna de Santa Rosa provides recreation and agricultural and industrial water supply plus wildlife habitat including cold freshwater habitat.State of California ''Water Quality Control Plan North Coastal Basin 1B'' July 1975 p.13 The Laguna is a complex of habitat types including freshwater

forest A forest is an area of land dominated by trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, and ecological function. The United Nations' ...

and

floodplain A floodplain or flood plain or bottomlands is an area of land adjacent to a river which stretches from the banks of its channel to the base of the enclosing valley walls, and which experiences flooding during periods of high discharge.Goudi ...

s, seasonal wetlands and

s, upland valley oak

savanna A savanna or savannah is a mixed woodland- grassland (i.e. grassy woodland) ecosystem characterised by the trees being sufficiently widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach the ground to ...

and freshwater tule

marsh A marsh is a wetland that is dominated by herbaceous rather than woody plant species.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p Marshes can often be found a ...

. A number of rare and endangered species are found in the Laguna, such as the

California tiger salamander The California tiger salamander (''Ambystoma californiense'') is a vulnerable amphibian native to California. It is a mole salamander. Previously considered to be a subspecies of the tiger salamander (''A. tigrinum)'', the California tiger sal ...

(''Ambystoma californiense''),

California freshwater shrimp California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the m ...

(''Syncaris pacifica'') and Sebastopol meadowfoam (''Limnanthes vinculans''). As an element of the Pacific Flyway, the Laguna is home to a large variety of

avifauna Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweight s ...

including Ridgway's rail, Canada goose (''Branta canadensis''),

turkey vulture The turkey vulture (''Cathartes aura'') is the most widespread of the New World vultures. One of three species in the genus '' Cathartes'' of the family Cathartidae, the turkey vulture ranges from southern Canada to the southernmost tip of Sout ...

(''Cathartes aura''), black-necked stilt (''Himantopus mexicanus''),

burrowing owl The burrowing owl (''Athene cunicularia''), also called the shoco, is a small, long-legged owl found throughout open landscapes of North and South America. Burrowing owls can be found in grasslands, rangelands, agricultural areas, deserts, or an ...

(''Athene cunicularia''),

great egret The great egret (''Ardea alba''), also known as the common egret, large egret, or (in the Old World) great white egret or great white heron is a large, widely distributed egret. The four subspecies are found in Asia, Africa, the Americas, and ...

(''Casmerodius albus''), great blue heron (''Ardea herodias'') and

American kestrel The American kestrel (''Falco sparverius''), also called the sparrow hawk, is the smallest and most common falcon in North America. It has a roughly two-to-one range in size over subspecies and sex, varying in size from about the weight of ...

(''Falco sparverius''). More than 200

of birds are known to reside in or feed and rest in the Laguna in the course of

migration Migration, migratory, or migrate may refer to: Human migration * Human migration, physical movement by humans from one region to another ** International migration, when peoples cross state boundaries and stay in the host state for some minimum le ...

. Salmonid species listed as threatened or endangered species are known to travel through the Laguna to spawn in its

tributaries A tributary, or affluent, is a stream or river that flows into a larger stream or main stem (or parent) river or a lake. A tributary does not flow directly into a sea or ocean. Tributaries and the main stem river drain the surrounding drainag ...

, including

steelhead trout Steelhead, or occasionally steelhead trout, is the common name of the anadromous form of the coastal rainbow trout or redband trout (O. m. gairdneri). Steelhead are native to cold-water tributaries of the Pacific basin in Northeast Asia and ...

(''Oncorhynchus mykiss'') and

coho salmon The coho salmon (''Oncorhynchus kisutch;'' Karuk: achvuun) is a species of anadromous fish in the salmon family (biology), family and one of the five Pacific salmon species. Coho salmon are also known as silver salmon or "silvers". The scientif ...

(''Oncorhynchus kisutch'').

Stewardship and land management

Much of the Laguna's most important habitat is in private hands, and multiple public agencies regulate various aspects of the Laguna's water, lands and natural resources. At the federal level, the U.S. Army Corps of Engineers has played a role in analysis of water quality, especially related to sediment issues, and the National Marine Fisheries Service of the

National Oceanographic and Atmospheric Administration The National Oceanic and Atmospheric Administration (abbreviated as NOAA ) is an United States scientific and regulatory agency within the United States Department of Commerce that forecasts weather, monitors oceanic and atmospheric conditio ...

regulates critical habitat and recovery efforts for threatened and endangered salmonid species. The state of California, through its Department of Fish and Game, has ownership involvement as well as an enforcement role in species protection, while the North Coast Regional Water Quality Control Board is responsible for regulating water quality in the Laguna. Locally, the Sonoma County Water Agency manages areas of the Laguna for flood control, and the City of Santa Rosa's Subregional

wastewater Wastewater is water generated after the use of freshwater, raw water, drinking water or saline water in a variety of deliberate applications or processes. Another definition of wastewater is "Used water from any combination of domestic, industrial ...

System's main plant is located in the Laguna floodplain and owns and manages adjacent lands for storage and agricultural reuse of treated wastewater as well as for habitat values. The City of

also owns lands in the Laguna which it manages as public parkland. In the

private sector The private sector is the part of the economy, sometimes referred to as the citizen sector, which is owned by private groups, usually as a means of establishment for profit or non profit, rather than being owned by the government. Employment The ...

, the Laguna de Santa Rosa Foundation plays an active role in planning, public education, restoration, research and implementation of education programs in the Laguna. On February 2, 2011, the Ramsar Convention on Wetlands recognized the Laguna as a wetlands of international importance. The designation, affecting took effect on April 16, 2011.

Bridges

At least ten bridges span the Laguna as it flows along the heavily populated U.S. Route 101 corridor: * at Old Redwood Highway near Commerce Boulevard, a concrete culvert built in 1956 * at U.S. Route 101 northbound, a concrete culvert built in 1956 * at U.S. Route 101 southbound, a concrete

tee beam A T-beam (or tee beam), used in construction, is a load-bearing structure of reinforced concrete, wood or metal, with a -shaped cross section. The top of the -shaped cross section serves as a flange or compression member in resisting compress ...

built in 1919 and reconstructed in 1994 * at Redwood Drive, a concrete culvert built in 1956 and reconstructed in 2002 * at Llano Road, a concrete continuous slab built in 1962 * at Todd Road, a concrete continuous slab built in 1973 * at Stony Point Road, a concrete continuous slab built in 1960 and reconstructed in 1994 * at State Route 12, concrete continuous tee beam built in 1921 , reconstructed in 1949 and reconstructed in 2017 * at Occidental Road, a concrete continuous slab built in 1990, and * at Guerneville Road, a concrete continuous tee beam built in 1957.

References

External links

Laguna de Santa Rosa Foundation official site
* ttp://www.lagunafoundation.org/knowledgebase/sites/default/files/Laguna%20Historical%20Hydrology%20Pilot%20Report_FINAL.pdf Laguna Foundation report on historical hydrology {{DEFAULTSORT:Laguna De Santa Rosa Ramsar sites in the United States Rivers of Sonoma County, California Sebastopol, California Wetlands of the San Francisco Bay Area Rohnert Park, California Rivers of Northern California Tributaries of the Russian River (California) Wetlands of California Landforms of Sonoma County, California