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86-552: The mission of the Sonoma Water is to, "effectively manage the water resources in our care for the benefit of people and the environment through resource and environmental stewardship, technical innovation, and responsible fiscal management." The Sonoma County Board of Supervisors acts as the Sonoma Water's Board of Directors. The Water Agency is a separate legal entity created by State law, having specific limited purposes and powers, and separate sources of funding. The Water Agency

172-446: A canal's full capacity may cause flooding to spread to other waterways and areas of the community, which causes damage. Defenses (both long-term and short-term) can be constructed to minimize damage, which involves raising the edge of the water with levees , embankments or walls. The high population and value of infrastructure at risk often justifies the high cost of mitigation in larger urban areas. The most effective way of reducing

258-659: A 1 in 1000 year flood (light blue) and low-lying areas in need of flood defence (purple). The most sustainable way of reducing risk is to prevent further development in flood-prone areas and old waterways. It is important for at-risk communities to develop a comprehensive Floodplain Management plan. In the US, communities that participate in the National Flood Insurance Program must agree to regulate development in flood-prone areas. One way of reducing

344-525: A certain amount of space in which floodwaters can fill. Other beneficial uses of dam created reservoirs include hydroelectric power generation, water conservation , and recreation. Reservoir and dam construction and design is based upon standards, typically set out by the government. In the United States, dam and reservoir design is regulated by the US Army Corps of Engineers (USACE). Design of

430-556: A coast). The spawning grounds for fish and other wildlife habitats can become polluted or completely destroyed. Some prolonged high floods can delay traffic in areas which lack elevated roadways. Floods can interfere with drainage and economical use of lands, such as interfering with farming. Structural damage can occur in bridge abutments , bank lines, sewer lines, and other structures within floodways. Waterway navigation and hydroelectric power are often impaired. Financial losses due to floods are typically millions of dollars each year, with

516-546: A connection to Clear Lake, the Russian River was beheaded from Clear Lake by a slide (at Cow Mountain , east of Ukiah). Now Clear Lake flows into the Sacramento River. The river incised a canyon into Fitch Mountain at an early time, before land levels were eroded to their present levels. The Russian River was prevented from flowing south into San Pablo Bay, due to a 113-foot high ridge at Cotati. Guerneville

602-517: A dam and reservoir follows guidelines set by the USACE and covers topics such as design flow rates in consideration to meteorological, topographic, streamflow, and soil data for the watershed above the structure. The term dry dam refers to a dam that serves purely for flood control without any conservation storage (e.g. Mount Morris Dam , Seven Oaks Dam ). Flood control channels are large and empty basins where surface water can flow through but

688-547: A five-year monitoring program using underwater cameras at two fish ladders just north of Forestville . They found that Chinook always were, and still are, "a relatively abundant, widely distributed, and naturally self-sustaining population". The authors found historic information dating to 1881 suggesting the presence of an ancestral population, and their genetic analysis found the Chinook both above and below barriers to fish passage to be of native, and not hatchery stock. In 2001

774-417: A flood does happen, the city can recover quickly and costs are minimized. For example, homes can be put on stilts, electrical and HVAC equipment can be put on the roof instead of in the basement, and subway entrances and tunnels can have built-in movable water barriers. New York City began a substantial effort to plan and build for flood resilience after Hurricane Sandy . Flood resilience technologies support

860-664: A lower elevation, the Russian River began cutting north into the drainage area of the Navarro River. Eroding up a fault line in Alexander Valley, the Russian River intersected the Navarro River just north of Cloverdale. This resulted in the stream capture of Big Sulphur Creek (formerly the upper Navarro River) and the north fork of the Navarro River, going north to Hopland and to Ukiah. The high valleys were eroded into rocky canyons for ten miles north of Cloverdale and for five miles east of Cloverdale. After establishing

946-641: A lowhead dam, is most often used to create millponds , but on the Humber River in Toronto, a weir was built near Raymore Drive to prevent a recurrence of the flood damage caused by Hurricane Hazel in October 1954. The Leeds flood alleviation scheme uses movable weirs which are lowered during periods of high water to reduce the chances of flooding upstream. Two such weirs, the first in the UK, were installed on

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1032-405: A method of using water to control flooding was discovered. This was accomplished by containing 2 parallel tubes within a third outer tube. When filled, this structure formed a non-rolling wall of water that can control 80 percent of its height in external water depth, with dry ground behind it. Eight foot tall water filled barriers were used to surround Fort Calhoun Nuclear Generating Station during

1118-469: A portion of the facility. AquaFence consists of interlocking panels which are waterproof and puncture-resistant, can be bolted down to resist winds, and use the weight of floodwater to hold them in place. Materials include marine-grade batlic laminate, stainless steel, aluminum and reinforced PVC canvas. The panels are reusable and can be stored flat between uses. The technology was designed as an alternative to building seawalls or placing sandbags in

1204-687: A southern colony at Fort Ross , the Russian-American Company contracted with American ships beginning in 1806, providing them with Aleuts and their baidarkas (kayaks) to hunt otter on the coast of Spanish California. Hudson's Bay Company 's Alexander R. McLeod reported in 1829, "The Country to the northward of Bodega is said to be rich in Beaver and no encouragement given to the Indians to hunt." The fur trapper Ewing Young , led an expedition up Putah Creek to Clear Lake and on to

1290-407: A total storage capacity of 118,000 acre-feet with a water supply pool of 70,000 acre-feet. https://commons.wikimedia.org/wiki/File%3ASonoma_Lake_aerial_view.jpg Located about 14 miles northwest of Healdsburg, Warm Springs Dam is a rolled earth embankment dam that forms Lake Sonoma. The Sonoma County Water Agency generates electricity at Warm Springs Dam through a hydroelectric turbine. Located at

1376-530: A tunnel constructed through a mountain ridge. Outflow from the powerhouse flows into the East Fork of the Russian River Located on the East Fork of the Russian River, Coyote Dam is a rolled earth embankment dam that forms Lake Mendocino. Lake Mendocino is a U.S. Army Corps of Engineers project that began storing water in 1959. It captures a drainage area of about 105 square miles, and provides

1462-476: A variety of flood protection projects, including Warm Springs Dam, Spring Lake, Coyote Valley Dam, Matanzas Creek Reservoir, Piner Creek Reservoir, Brush Creek Middle Fork Reservoir, and Spring Creek Reservoir. The Water Agency also manages a proactive stream maintenance program that maintains more than 80 miles of creeks throughout the area. In 1995, legislation made the Water Agency responsible for managing

1548-510: A water supply for agriculture. The river's floodplain includes many vineyards, and an area of the Russian River Valley was approved as an American Viticultural Area in 1983 and enlarged in 2006. It produces Chardonnay and pinot noir wines in addition to other wine varietals, and is home to many small and several large commercial wineries. Flood control Flood management describes methods used to reduce or prevent

1634-629: A wide range of flood management methods including but are not limited to flood mapping and physical implication measures. Flood risk management looks at how to reduce flood risk and how to appropriately manage risks that are associated with flooding. Flood risk management includes mitigating and preparing for flooding disasters, analyzing risk, and providing a risk analysis system to mitigate the negative impacts caused by flooding. Flooding and flood risk are especially important with more extreme weather and sea level rise caused by climate change as more areas will be effected by flood risk. Flood mapping

1720-559: Is a broad term that includes measures to control or mitigate flood waters, such as actions to prevent floods from occurring or to minimize their impacts when they do occur. Flood management methods can be structural or non-structural: There are several related terms that are closely connected or encompassed by flood management. Flood management can include flood risk management, which focuses on measures to reduce risk, vulnerability and exposure to flood disasters and providing risk analysis through, for example, flood risk assessment . In

1806-575: Is a flood defense system designed to protect people and property from inland waterway floods caused by heavy rainfall, gales, or rapid melting snow. The SCFB can be built to protect residential properties and whole communities, as well as industrial or other strategic areas. The barrier system is constantly ready to deploy in a flood situation, it can be installed in any length and uses the rising flood water to deploy. When permanent defenses fail, emergency measures such as sandbags , inflatable impermeable sacks, or other temporary barriers are used. In 1988,

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1892-681: Is a related but separate concept describing a broader set of strategies taken to reduce flood risk and potential impact while improving resilience against flood events. As climate change has led to increased flood risk an intensity, flood management is an important part of climate change adaptation and climate resilience . For example, to prevent or manage coastal flooding , coastal management practices have to handle natural processes like tides but also sea level rise due to climate change. The prevention and mitigation of flooding can be studied on three levels: on individual properties, small communities, and whole towns or cities. Flood management

1978-571: Is a southward-flowing river that drains 1,485 sq mi (3,850 km ) of Sonoma and Mendocino counties in Northern California . With an annual average discharge of approximately 1,600,000 acre feet (2.0 km ), it is the second-largest river (after the Sacramento River ) flowing through the nine-county Greater San Francisco Bay Area , with a mainstem 115 mi (185 km) long. The Southern Pomo know

2064-472: Is a tool used by governments and policy makers to delineate the borders of potential flooding events, allowing educated decisions to prevent extreme flooding events. Flood maps are useful to create documentation that allows policy makers to make informed decisions about flood hazards. Flood mapping also provides conceptual models to both the public and private sectors with information about flooding hazards. Flood mapping has been criticized in many areas around

2150-774: Is bordered by U.S. Route 101 , to join the East Fork Russian River just below Lake Mendocino . From there the Russian River flows south, past Ukiah through the Ukiah Valley and Hopland through the Sanel Valley , and crosses into Sonoma County just north of Cloverdale . Closely paralleled by U.S. Route 101, it descends into the Alexander Valley , where it is joined by Big Sulphur Creek . It flows south past Cloverdale , Asti , and Geyserville . East of Healdsburg , Maacama Creek joins

2236-901: Is built on an abandoned meander of the river. Near Guerneville, another meander cut short Smith Creek. The Mendocino Plateau is a part of the Franciscan Assemblage . A portion of the Eel River is diverted to headwaters of the Russian River in Potter Valley , via a scheme known as the Potter Valley Project . The Sonoma County Water Agency draws drinking water from the Russian River for sale to several hundred thousand residents of Sonoma, Mendocino, and northern Marin counties. Santa Rosa's Laguna Wastewater Treatment Plant treats sewage from several communities to tertiary standards and returns some of it to

2322-467: Is effective at managing flooding. However, it is best practice within landscape engineering to rely more on soft infrastructure and natural systems , such as marshes and flood plains , for handling the increase in water. Flood management can include flood risk management, which focuses on measures to reduce risk, vulnerability and exposure to flood disasters and providing risk analysis through, for example, flood risk assessment . Flood mitigation

2408-452: Is home to three species of fish that are threatened or endangered. These species are the Chinook salmon, the steelhead trout, and the coho salmon. Water Agency staff conducts fisheries research and monitoring activities to support ongoing Agency operations and Endangered Species Act compliance. The Russian River Biological Opinion is a federally mandated 15-year blueprint to help save endangered fish and ensure our water supply. The Water Agency

2494-520: Is indicated and in such cases environmentally helpful solutions may provide solutions. Natural flooding has many beneficial environmental effects. This kind of flooding is usually a seasonal occurrence where floods help replenish soil fertility, restore wetlands and promote biodiversity . Flooding has many impacts. It damages property and endangers the lives of humans and other species. Rapid water runoff causes soil erosion and concomitant sediment deposition elsewhere (such as further downstream or down

2580-780: Is involved in a number of programs and initiatives to study the groundwater resources of the region through the Santa Rosa Plain Groundwater Program, the Sonoma Valley Groundwater Program, the Stormwater/Groundwater Recharge Program, and the Salt and Nutrient Management Plans. The Russian River begins in central Mendocino County, about 15 miles north of Ukiah. It drains 1,485 square miles watershed and it stretches 110 miles long. It reaches

2666-404: Is not retained (except during flooding ), or dry channels that run below the street levels of some larger cities , so that if a flash flood occurs the excess water can drain out along these channels into a river or other bodies of water . Flood channels are sometimes built on the former courses of natural waterways as a way to reduce flooding. Channelization of this sort was commonly done in

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2752-735: Is part of environmental engineering . It involves the management of water movement, such as redirecting flood run-off through the use of floodwalls and flood gates to prevent floodwaters from reaching a particular area. Flood mitigation is a related but separate concept describing a broader set of strategies taken to reduce flood risk and potential impact while improving resilience against flood events. These methods include prevention, prediction (which enables flood warnings and evacuation), proofing (e.g.: zoning regulations), physical control ( nature-based solutions and physical structures like dams and flood walls ) and insurance (e.g.: flood insurance policies). Flood relief methods are used to reduce

2838-568: Is thus different from County departments, which are created by the Board of Supervisors for administrative purposes, but are not separate legal entities. Sonoma Water was created as a special district in 1949 by the California Legislature to provide flood protection and water supply services. Providing flood protection is an important role in this community. The Water Agency has partnered with federal agencies to help build and manage

2924-436: The 2011 Missouri River Flooding . Instead of trucking in sandbag material for a flood, stacking it, then trucking it out to a hazmat disposal site, flood control can be accomplished by using the on site water. However, these are not fool proof. A 8 feet (2.4 m) high 2,000 feet (610 m) long water filled rubber flood berm that surrounded portions of the plant was punctured by a skid-steer loader and it collapsed flooding

3010-577: The California Bays and Estuaries Policy . The mouth is about 60 mi (100 km) north of the San Francisco Bay 's Golden Gate bridge. The lower Russian River is a popular spring, summer, and fall destination for navigation and recreation. It is very safe at that time for swimming and boating, with a gentle current. The river is dangerous in the winter, with swift current and muddy water. The geographer R. S. Holway wrote of

3096-996: The Coho salmon ( Oncorhynchus kisutch ) had dwindled to less than four returning spawners per year. These low numbers were the catalyst for the Russian River Coho Salmon Captive Broodstock Program, a recovery effort in which offspring from hatchery-reared adults are released into the river system. In 2011, biologists estimate that more than 190 adult coho may have returned to the Russian River watershed, beginning with early storms in October and peaking in December. High priority tributaries for restoration of stream flows and habitat for Coho include Dutch Bill , Grape, Green Valley , Mark West and Mill Creeks . Similarly, early twentieth-century naturalists were skeptical that California Golden beaver ( Castor canadensis subauratus ) were extant in

3182-593: The Mendocino County Coast in March, 1833. James Weeks, a member of Young's 1833 fur brigade wrote: "They broke up all the beaver lodges on the lake, I believe the finest and largest beaver we caught there, we arrived at the Russian River and pitched camp sent out, trappers found signs set traps caught beavers..." This historical observer record is consistent with the Southern Pomo , who inhabited

3268-552: The Pajaro River . Khlebnikov stated in his "1820 Travel Notes", "Mr. Kuskov had sent two baidarkas to the Slavyanka River to catch sturgeon, and they returned today with ten fish...the largest one exceeding two arshins (4.67 feet) long". Moyle's Inland Fishes of California states that there were historic runs of white, but not green, sturgeon in the Russian River. White sturgeon are the largest freshwater fish in

3354-485: The River Aire in October 2017 at Crown Point, Leeds city centre and Knostrop . The Knostrop weir was operated during the 2019 England floods . They are designed to reduce potential flood levels by up to one metre. Coastal flooding is addressed with coastal defenses, such as sea walls , beach nourishment , and barrier islands . Tide gates are used in conjunction with dykes and culverts. They can be placed at

3440-458: The 1960s, but is now often being undone, with "rechannelization" through meandering, vegetated, porous paths. This is because channellizing the flow in a concrete chute often made flooding worse. Water levels during a flood tend to rise, then fall, exponentially. The peak flood level occurs as a very steep, short spike; a quick spurt of water. Anything that slows the surface runoff (marshes, meanders, vegetation, porous materials, turbulent flow,

3526-642: The California Statues of 1949, the Agency was originally called the Sonoma County Flood Control and Water Conservation District. It has grown with the region it serves and now has an annual budget of over $ 170 million and employs 197 full-time equivalents . Although its board of directors is identical to the county's Board of Supervisors , the Agency is a separate legal entity with its own funding. Since 1961, its board has had

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3612-748: The Kostromitinov Ranch, stretched along the Russian River near the mouth of Willow Creek. The redwoods that lined its banks drew loggers to the river in the late 19th century. According to the USGS, variant names of the Russian River include Misallaako, Rio Ruso, Shabaikai, and Slavyanka. The Russian River springs from the Laughlin Range about 5 mi (8 km) east of Willits in Mendocino County. It flows generally southward to Redwood Valley , then past Calpella , where it

3698-536: The Pacific Ocean at the town Jenner, which is located approximately 20 miles west of Santa Rosa. It flows southward until Mirabel Park where the direction changes to westward as it crosses part of the Coast Range. There are five principal tributaries: the East Fork of the Russian River, Big Sulphur Creek, Mark West Creek, Maacama Creek, and Dry Creek. Three major reservoir projects provide water supply for

3784-751: The Russian River in his 1917 paper "The Russian River: A Characteristic Stream of the California Coast Ranges". Originally, the Russian River was one of several rivers draining westward from the Mayacamas Mountains through the Mendocino Plateau to the sea, a region lifted up by tectonic forces. The Navarro River drained from the Cobb Mountain area, while the Russian River drained from the Mt. St. Helena area. Being at

3870-485: The Russian River watershed: Lake Pillsbury on the Eel River, Lake Mendocino on the East Fork of the Russian River, and Lake Sonoma on Dry Creek. Lake Mendocino and Lake Sonoma provide water for agriculture, municipal and industrial uses, in addition to maintaining the minimum stream flows required by Agency water rights permits. These minimum stream flows provide recreation and fish passage for salmon and steelhead. Most of

3956-556: The Russian River. After it makes a series of sweeping bends, the Healdsburg Memorial Bridge carries Old Redwood Highway over the river just upstream of U.S. Route 101 's Healdsburg crossing. It receives water from Lake Sonoma via Dry Creek . The river turns westward, where it is spanned by the Wohler Bridge, and it is joined by Mark West Creek north of Forestville , followed by Green Valley Creek to

4042-809: The Spanish called it the San Ygnacio , and in 1843 the Spanish land grant referred to it as Rio Grande . The river takes its current name from Russian Ivan Kuskov of the Russian-American Company, who explored the river in the early 19th-century and established the Fort Ross colony 10 mi (16 km) northwest of its mouth. The Russians called it the Slavyanka River , meaning " Slav River". ( Slavyanka in Russian means "Slavic woman".) They established three ranches near Fort Ross, one of which,

4128-561: The United States. The Russian River is the largest river in the Central California Coast steelhead trout ( Oncorhynchus mykiss ) distinct population segment . Natural waterfalls and the two major dams, Warm Springs (built in 1982) and Coyote (built in 1959), have isolated anadromous steelhead from its non-oceangoing rainbow trout form above the impassable barriers. Recent genetic studies on steelhead collected at 20 different sites both above and below passage barriers in

4214-525: The abundance of seal, otter and beaver were the principal factors which favored this colonization." An 1816 report by the Russian-American Company's Board of Directors said that it was establishing a settlement to introduce agriculture.(page 33, After December 16, 1813: A report to Emperor Alexander I from the Russian American Company Council, concerning trade with California and the establishment of Fort Ross) Before establishing

4300-504: The amount of mitigation needed to protect humans and buildings from flooding events. Similarly, flood warning systems are important for reducing risks. Following the occurrence of flooding events, other measures such as rebuilding plans and insurance can be integrated into flood risk management plans. Flood risk management strategy diversification is needed to ensure that management strategies cover several different scenarios and ensure best practices. Flood risk management aims to reduce

4386-650: The building site, including scour protection for shoreline developments, improving rainwater in filtration through the use of permeable paving materials and grading away from structures, and inclusion of berms , wetlands or swales in the landscape. When more homes, shops and infrastructure are threatened by the effects of flooding, then the benefits of protection are worth the additional cost. Temporary flood defenses can be constructed in certain locations which are prone to floods and provide protection from rising flood waters. Rivers running through large urban developments are often controlled and channeled. Water rising above

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4472-469: The canyon between Cloverdale and Hopland. This vulnerability was demonstrated in March 1982 when a tank car of formaldehyde was vandalized in Ukiah. Emergency response personnel were able to clean up approximately half of the 21,000 US gallons (79,000 L) spilled, and a fortuitous combination of Lake Mendocino reservoir inventory and late winter storms helped flush the remainder through the river and into

4558-601: The capacity of stormwater systems. This separates stormwater from blackwater , so that overflows in peak periods do not contaminate rivers. One example is the SMART Tunnel in Kuala Lumpur. Some methods of flood control have been practiced since ancient times. These methods include planting vegetation to retain extra water, terracing hillsides to slow flow downhill, and the construction of floodways (man-made channels to divert floodwater). Other techniques include

4644-676: The coastal streams of the Bay Area. However, the Russian-American Company 's Ivan Kuskov sailed into Bodega Bay in 1809 on the Kodiak and, after exploring 50 miles of the Russian River, returned to Novo Arkhangelsk, Alaska (Sitka), with beaver skins and over 2,000 sea otter ( Enhydra lutris ) pelts. The Russians' stated reason for establishing a settlement in Alta California was, "The rich, fertile soil [and]

4730-435: The confluence of Warm Springs Creek and Dry Creek, this lake began storing water in 1984 and has a total storage capacity of 381,000 acre-feet with a water supply pool of 212,000 acre-feet. Warm Springs Dam is a multi-purpose reservoir serves as a flood control , water supply and recreational facility. The Water Agency is the local cost-sharing partner for Warm Springs Dam, and determines the amount of water to be released when

4816-417: The construction of levees, lakes, dams, reservoirs, retention ponds to hold extra water during times of flooding. Many dams and their associated reservoirs are designed completely or partially to aid in flood protection and control. Many large dams have flood-control reservations in which the level of a reservoir must be kept below a certain elevation before the onset of the rainy/summer melt season to allow

4902-473: The context of natural hazards and disasters , risk management involves "plans, actions, strategies or policies to reduce the likelihood and/or magnitude of adverse potential consequences, based on assessed or perceived risks". Flood control , flood protection , flood defence and flood alleviation are all terms that mean "the detention and/or diversion of water during flood events for the purpose of reducing discharge or downstream inundation". Flood control

4988-511: The county sanitation zones and districts, which provide wastewater collection and treatment, and recycled water distribution and disposal services for approximately 22,000 residences and businesses. The zones include Airport/Larkfield/Wikiup, Geyserville, Penngrove, and Sea Ranch. The sanitation districts include the Occidental, Russian River, Sonoma Valley, and South Park County Sanitation Districts The Russian River and its major tributaries

5074-568: The damage caused by flooding is to remove buildings from flood-prone areas, leaving them as parks or returning them to wilderness. Floodplain buyout programs have been operated in places like New Jersey (both before and after Hurricane Sandy ), Charlotte , North Carolina, and Missouri . In the United States, FEMA produces flood insurance rate maps that identify areas of future risk, enabling local governments to apply zoning regulations to prevent or minimize property damage. Buildings and other urban infrastructure can be designed so that even if

5160-466: The detrimental effects of flood waters. Flooding can be caused by a mix of both natural processes, such as extreme weather upstream, and human changes to waterbodies and runoff. Flood management methods can be either of the structural type (i.e. flood control) and of the non-structural type. Structural methods hold back floodwaters physically, while non-structural methods do not. Building hard infrastructure to prevent flooding, such as flood walls ,

5246-541: The effects of flood waters or high water levels during a flooding event. They include evacuation plans and rescue operations. Flood relief is part of the response and recovery phase in a flood management plan. Floods are caused by many factors or a combination of any of these generally prolonged heavy rainfall (locally concentrated or throughout a catchment area), highly accelerated snowmelt , severe winds over water, unusual high tides, tsunamis , or failure of dams, levees , retention ponds , or other structures that retained

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5332-443: The fast recovery of individuals and communities affected, but their use remains limited. Flooding can occur in cities or towns as urban flooding . It can also take place by the sea as coastal flooding . Sea level rise can make coastal flooding worse. In some areas there are also risks of glacial lake outburst floods . There are many adaptation options for flooding: More frequent drenching rains may make it necessary to increase

5418-817: The flow", and deliberately flood some low-lying areas, ideally vegetated, to act as sponges, letting them drain again as the floodwaters go down. Excess water can be used for groundwater replenishment by diversion onto land that can absorb the water. This technique can reduce the impact of later droughts by using the ground as a natural reservoir. It is being used in California, where orchards and vineyards can be flooded without damaging crops, or in other places wilderness areas have been re-engineered to act as floodplains. In many countries, rivers are prone to floods and are often carefully managed. Defenses such as levees, bunds , reservoirs, and weirs are used to prevent rivers from bursting their banks. A weir, also known as

5504-441: The gate. A flood barrier , surge barrier or storm surge barrier is a specific type of floodgate , designed to prevent a storm surge or spring tide from flooding the protected area behind the barrier. A surge barrier is almost always part of a larger flood protection system consisting of floodwalls , levees (also known as dikes), and other constructions and natural geographical features. The self-closing flood barrier (SCFB)

5590-520: The human and socio-economic losses caused by flooding and is part of the larger field of risk management . Flood risk management analyzes the relationships between physical systems and socio-economic environments through flood risk assessment and tries to create understanding and action about the risks posed by flooding. The relationships cover a wide range of topics, from drivers and natural processes, to models and socio-economic consequences. This relationship examines management methods which includes

5676-496: The lake level is in the water supply pool, and the US Army Corps of Engineers manages flood control releases. Sonoma Water is a water wholesaler that primarily sells potable water to nine municipalities and water districts in two counties: Additionally, there are several smaller water companies and districts in Sonoma County that also receive water from the Agency. These include: Formed on October 1, 1949 by Chapter 994 of

5762-760: The lower half of the Russian River, having a word for beaver ṱ'ek:e and beavers in their "Coyote Stories". In 1881 the Sacramento Daily Union newspaper reported, "Beavers are being trapped near Healdsburg" (placing them again on the Russian River). The Russian River State Marine Reserve and Russian River State Marine Conservation Area protect the Russian River Estuary. Like underwater parks, these marine protected areas help conserve ocean and freshwater wildlife and marine ecosystems. The river provides groundwater recharge and

5848-422: The main drivers of floods interact with each other. Flood modelling combines factors such as terrain, hydrology , and urban topography to reproduce the evolution of a flood in order to identify the different levels of flooding risks associated with each element exposed. The modelling can be carried out using hydraulic models, conceptual models, or geomorphic methods. Nowadays, there is a growing attention also in

5934-427: The mouth of streams or small rivers, where an estuary begins or where tributary streams, or drainage ditches connect to sloughs . Tide gates close during incoming tides to prevent tidal waters from moving upland, and open during outgoing tides to allow waters to drain out via the culvert and into the estuary side of the dike. The opening and closing of the gates is driven by a difference in water level on either side of

6020-634: The ocean before local water storage inventories were exhausted. The Russian River reached flood stage of 32 feet (9.8 m) at Guerneville about five times per decade through the last half of the 20th century. Historic flood peaks were 49.5 feet (15.1 m) in February 1986, 48 feet (15 m) in January 1995, 47.6 feet (14.5 m) in December 1955, 47.3 feet (14.4 m) in December 1964, and 46.9 feet (14.3 m) in February 1940. Through effective use of Lake Mendocino and Lake Sonoma flood capacity

6106-439: The path of floodwaters. Other solutions, such as HydroSack , are polypropylene exteriors with wood pulp within, though they are one-time use. There are several methods of non-structural flood management that form part of flood risk management strategies. These can involve policies that reduces the amount of urban structures built around floodplains or flood prone areas through land zoning regulations. This helps to reduce

6192-539: The production of maps obtained with remote sensing . Flood modelling is helpful for determining building development practices and hazard mitigation methods that reduce the risks associated with flooding. Stakeholder engagement is a useful tool for flood risk management that allows enhanced public engagement for agreements to be reached on policy discussions. Different management considerations can be taken into account including emergency management and disaster risk reduction goals, interactions of land-use planning with

6278-906: The right to sell bonds without voter approval. Its administrative offices are located at 404 Aviation Boulevard in Santa Rosa: 38°30′42″N 122°47′1″W  /  38.51167°N 122.78361°W  / 38.51167; -122.78361 . In 2009 the Sonoma County Water Agency was honored with the California Sustainability Alliance's Sustainability Showcase Award. The award commended the Water Agency for their commitment to Carbon-Free Water by 2015 and for their use in innovative sustainability practices, programs, technologies and policies. Russian River (California) The Russian River ( Southern Pomo : Ashokawna , Spanish : Río Ruso )

6364-572: The risk to people and property is through the production of flood risk maps. Most countries have produced maps which show areas prone to flooding based on flood data. In the UK , the Environment Agency has produced maps which show areas at risk. The map to the right shows a flood map for the City of York , including the floodplain for a 1 in 100-year flood (dark blue), the predicted floodplain for

6450-475: The river as Ashokawna ( ʔaš:oʔkʰawna ), "east water place" or "water to the east", and as Bidapte , "big river." Juan Rodríguez Cabrillo and his expedition may have travelled as far north as the Russian River in November 1542 before storms forced them to turn back south towards Monterey. The earliest Slavic name for the river, Slavyanka , appears on a Russian-American Company chart dated 1817. In 1827

6536-538: The river by way of the Laguna de Santa Rosa . Water transferred from the Eel River and released from Lake Mendocino flows through the Russian River channel to withdrawal points in Sonoma County. Although this method of transport supports aquatic and riparian zone habitats, it is vulnerable to chemical contamination from transportation accidents where the river is in close proximity to highway 101 and Northwestern Pacific Railroad transportation corridors in locations like

6622-518: The river has exceeded flood stage at Guerneville less frequently in the 21st century, but in late February 2019 it flooded to levels comparable to 1986. The river provides wildlife habitat including warm and cold freshwater habitat for fish migration and spawning. Historically it is interesting as one of two Northern California coastal rivers mentioned in the early nineteenth century by Russian explorer K. T. Khlebnikov as hosting sturgeon, presumably white sturgeon ( Acipenser transmontanus ), along with

6708-455: The river spreading over a floodplain) will slow some of the flow more than other parts, spreading the flow over time and blunting the spike. Even slightly blunting the spike significantly decreases the peak flood level. Generally, the higher the peak flood level, the more flood damage is done. Straight, clear, smooth concrete-walled channels speed up flow, and are therefore likely to make flooding downstream worse. Modern flood control seeks to "slow

6794-595: The south. The river passes Rio Nido and Guerneville . In that area, State Route 116 parallels the river, bordering it past Guernewood Park and Monte Rio . Austin Creek enters from the north before the River passes through Duncans Mills . State Route 1 crosses over the river before it flows into the Pacific Ocean between Jenner and Goat Rock Beach . The Russian River estuary is recognized for protection by

6880-432: The spike. Even slightly blunting the spike significantly decreases the peak flood level. Generally, the higher the peak flood level, the more flood damage is done. Modern flood control seeks to "slow the flow", and deliberately flood some low-lying areas, ideally vegetated, to act as sponges, letting them drain again as the floodwaters go down. Where floods interact with housing, industry and farming that flood management

6966-472: The streamflow in the Russian River during the summer is provided by water imported from the Eel River. Streamflows are augmented by releases from Lake Mendocino and Lake Sonoma. Scott Dam is a concrete gravity dam on the Eel River captures a drainage area of 298 square miles and forms Lake Pillsbury. Lake Pillsbury has a storage capacity of 86,388 acre-feet. Since 1923, the lake stored water for diversion to PG&E's Potter Valley Hydroelectric powerhouse through

7052-400: The water. Water levels during a flood tend to rise, then fall, very abruptly. The peak flood level occurs as a very steep, short spike; a quick spurt of water. Anything that slows the surface runoff (marshes, meanders, vegetation, porous materials, turbulent flow, the river spreading over a floodplain) will slow some of the flow more than other parts, spreading the flow over time and blunting

7138-461: The water. Flooding can be exacerbated by increased amounts of impervious surface or by other natural hazards such as wildfires, which reduce the supply of vegetation that can absorb rainfall. During times of rain, some of the water is retained in ponds or soil, some is absorbed by grass and vegetation, some evaporates, and the rest travels over the land as surface runoff . Floods occur when ponds, lakes, riverbeds, soil, and vegetation cannot absorb all

7224-512: The watershed found that despite the fact that 30 million hatchery trout were stocked in the river from 1911 to 1925, the steelhead remain of native and not hatchery stock. Until recently, most reviews indicated that Chinook salmon ( Oncorhynchus tshawytscha ) were always scarce on the Russian River. However, in 2007, the Sonoma County Water Agency completed a comprehensive re-evaluation of historical records, coupled with

7310-500: The world, due to the absence of public accessibility, technical writing and data, and lack of easy-to-understand information. However, revived attention towards flood mapping has renewed the interest in enhancing current flood mapping for use as a flood risk management method. Flood modelling is a tool used to model flood hazard and the effects on humans and the physical environment. Flood modelling takes into consideration how flood hazards, external and internal processes and factors, and

7396-419: The worst floods in recent U.S. history having cost billions of dollars. Property owners may fit their homes to stop water entering by blocking doors and air vents, waterproofing important areas and sandbagging the edges of the building. Private precautionary measures are increasingly important in flood risk management. Flood mitigation at the property level may also involve preventative measures focused on

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