Northern California Catastrophic Flood Response Plan

Annex B: Situation/Intelligence

1.0 Situation

The Northern California flood scenario is a severe incident that could inundate a great portion of the Sacramento River basin and the Delta region in the Central Valley. Flooding would affect local and state governments along with millions of people requiring widespread evacuations. Infrastructure restoration could take several months. Flooding would also seriously disrupt commerce and cause more than $100 billion in damages. A weather event large enough to cause catastrophic flooding in the Delta will also have far reaching impacts affecting other areas of the state and possibly several other Western States.

Exact weather and flood inundation areas are hard to predict for a flood response scenario, as local conditions (e.g. river/stream levels, reservoir conditions, snowpack levels) and storm intensity typically determine the magnitude and location of resulting flooding. However, with the current technology capabilities available to predict weather patterns, enough notice typically precedes severe weather events to allow sufficient preparedness activities to occur to help mitigate some of the damages.

This plan is “risk based” versus scenario driven. The standard references for establishing the location of flood hazards are the Flood Insurance Rate Map (FIRM) floodplains, part of a national insurance system maintained under the National Flood Insurance Program (NFIP). The FIRM maps not only identify the flood hazard zones for insurance and floodplain management purposes, but also provide a statement of probability of future occurrence. To determine the impact of a catastrophic flood, planners used a risk based approach utilizing the FEMA Federal Insurance Rate Maps (FIRM) 100 and 500 year flood plains in combination with the US Army Corps of Engineers (USACE) 100 and 500 year comprehensive flood plain study conducted after the 1997 floods. Both 100 year and both 500 year flood plains were combined to create the 100 and 500 year event boundaries. To determine assets at “risk” and to avoid counting assets twice, the 100 and 500 year flood plains were analyzed separately. A 100 year flood event is a flood that has a 1 percent chance of occurring in any given year, while a 500 year flood event has a 0.2 percent chance of occurring in any given year. See Figure 1 below for a map of the flood inundation area for the 10 county planning area.

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Figure B-1: Maximum Flood Inundation – 100 Year and 500 Year Flood Event

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Table B-1 below depicts the total acres exposed to flooding in the 10 county planning area. Sutter County (79%) has the largest landmass exposed to flooding in a 500 year event.

Table B-1: Acres Exposed to Flooding

Area Exposed in Area Exposed in 100 yr Flood Zone 500 yr Flood Zone* County Total Acreage % of Area % of Area Acres Acres Exposed Exposed Butte 1.1 million 198,800 19 271,300 25 Colusa 740,000 175,300 24 229,200 31 Contra Costa 514,000 113,000 22 125,300 24 Glenn 849,100 123,300 15 133,800 16 Sacramento 636,100 119,300 19 273,500 43 San Joaquin 912,600 242,900 27 435,200 48 Solano 582,400 119,200 34 224,400 39 Sutter 389,300 195,000 50 308,400 79 Yolo 653,500 239,900 37 260,600 40 Yuba 412,000 51,800 13 95,400 23 Source: DWR California’s Flood Future Report 2013 *500 Yr Flood Zone includes both 100 and 500 Year statistics Planning Area Demographics There are over 4.3 million people in the 10 counties comprising the region covered by this plan, with over 1.4 million people exposed to flooding. Sutter County has the highest population exposed to flooding (97%) followed by Yuba County (71%), San Joaquin County (59%), Sacramento County (42%), Yolo County (38%), and Glenn County (35%). The remaining counties have less than 30% of their population exposed to flooding. There are five cities with populations over 100,000. Sacramento (466,488) and Stockton (302,389) are the two largest. The daily commuting population in downtown Sacramento can swell to over 110,000.

Of the 1.4 million people exposed to flooding, 137,769 (39%) are children under 5 years of age, 171,620 (30%) are over the age of 65, and there are 139,274 (37%) households with one or more disabled persons. Additionally there are 86,916 (44%) households below poverty and 37,925 (43%) that do not speak English.

See figure B-2 below for more demographic information regarding the 100 and 500 year flood zones. Specific county demographic information can be found in the Operational Area Annex.

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Table B-2: Population Statistics by County

Population Population Total Total Exposed to Exposed to Population Operational Area/County Population Flooding in Flooding in Exposed to 100 Yr Event 500 Yr Event Flooding Branch I

Division A – Yolo 206,439 68,614 (33%) 9,587 (5%) 78,201 (38%) Division B – Colusa 22,143 4,210 (19%) 2,106 (10%) 6,316 (29%) Division C – Glenn 28,864 4,517 (16%) 5,532 (19%) 10,049 (35%) Branch II Division D – Butte 223,456 17,327 (8%) 31,620 (14%) 48,947 (22%) Division E – Sutter 95,894 9,479 (10%) 83,757 (87%) 93,236 (97%) Division F – Yuba 74,505 26,594 (36%) 26,229 (35%) 52,823 (71%) Branch III Division G – Sacramento 1,456,424 103,209 (7%) 502,691 (35%) 605,900 (42%) Division H – San Joaquin 711,503 53,524 (8%) 369,064 (52%) 422,588 (59%) Branch IV Division J – Contra Costa 1,089,972 47,069 (4%) 32,932 (3%) 80,001 (7%) Division K – Solano 422,431 39,661 (9%) 21,926 (5%) 61,587 (15%) Totals 4,331,631 374,204 (9%) 1,085,444 (25%) 1,459,648 (34%) Source: 2015 Census Data

Table B-3: Demographic Statistics in 100 and 500 Year Flood Zones

# Out of % Out of # in 100 % in % in 500 # % All Branches Total # In 500 Yr Flood Flood Yr 100 Yr Yr Exposed Exposed Zone Zone 2015 Total 4,331,631 374,204 8.64% 1,085,444 25.06% 1,459,648 33.70% 2,871,983 66.30% Population 2015 Total 1,489,890 123,342 8.28% 380,329 25.53% 503,671 33.81% 986,219 66.19% Households 2015 Vacant 113,885 9,531 8.37% 38,593 33.89% 48,124 42.26% 65,761 57.74% Households Households 198,987 18,089 9.09% 68,827 34.59% 86,916 43.68% 112,071 56.32% Below Poverty Households with 1+ Disabled 377,852 33,751 8.93% 105,523 27.93% 139,274 36.86% 238,578 63.14% Persons Number of 155,211 11,341 7.31% 50,944 32.82% 62,285 40.13% 92,926 59.87% Businesses Unemployed 164,974 11,565 7.01% 56,535 34.27% 68,100 41.28% 96,874 58.72% (Age 16+) At Risk - 5 and 348,301 24,982 7.17% 112,787 32.38% 137,769 39.55% 210,532 60.45% Under At Risk - Under 876,680 75,838 8.65% 228,836 26.10% 304,674 34.75% 572,006 65.25% 14

At Risk - Over 65 572,645 43,629 7.62% 127,991 22.35% 171,620 29.97% 401,025 70.03%

Non-English 88,227 6,953 7.88% 30,972 35.10% 37,925 42.99% 50,302 57.01% Speakers

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Operational Impacts from a Severe Flood Event (Keep or remove - need to update) Any severe flood event would have operational impacts in the following key areas:

 Damage to infrastructure – Damage to transportation, water, wastewater, petroleum, power, medical, and housing infrastructure will result in requirements for a full range of support in all core capability areas. Details are contained in appendices of Annex C (Operations).  Loss of transportation – Damage to transportation networks could cause large population areas to become isolated and the supply chain serving millions of Bay Area residents to become degraded. Access, which is the center of gravity for all response and recovery activities, will be reduced due to damaged transportation routes. This will affect the deployment of resources and mutual aid, the provision of mass care and sheltering services, and the reconstitution of infrastructure.  Loss of water and wastewater services – A severe earthquake will damage water utility pipelines and facilities, resulting in interrupted sources of supply and ultimately loss of service. Major conveyance systems, including the Hetch Hetchy aqueducts, EBMUD aqueducts, South Bay aqueduct, and numerous local pipelines, cross the Hayward fault. While seismic improvements have been made to many of these systems at fault crossings, a severe Hayward or San Andreas Fault rupture will cause water system outages.  Loss of electrical power – A severe earthquake could damage much of the Bay Area’s electrical power infrastructure. Electrical transmission lines and towers will likely fail as a result of ground shaking; gas pipeline breaks and leaks will occur, creating hazardous conditions and fires; and power could be out to communities for weeks, due to lack of repair parts caused by high demand and manufacturing delays.  Loss of communications capabilities – Extensive damage to existing communications infrastructure would result from a severe earthquake—damage that could take several weeks or months to repair. Neither landline nor cellular telephone systems will work for at least the first day post-event, probably longer, due to system overload and damage to cell phone towers. Loss of communications capabilities will impact the response and needed communication with the public.  Impacts to State Government -

Tribal Governments There are nine federally recognized tribal governments in the planning area as listed below. In a worst case scenario, three tribes may require assistance.

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Table B-4: Federally Recognized Tribes

County Tribe Inundation Butte Berry Creek Rancheria of Maidu Indians 100 Yr Flood Event Butte Estom Yumeka Maidu Tribe of the Enterprise Rancheria Out of Flood Zone Butte Mechoopda Indian Tribe of Chico Rancheria Out of Flood Zone Butte Mooretown Rancheria of Maidu Indians Out of Flood Zone Colusa Cachil DeHe Band of Wintun Indians 100 Yr Flood Zone Colusa Cortina Indian Rancheria of Wintun Indians Out of Flood Zone Glenn Grindstone Indian Rancheria of Wintun-Wailaki Indians 100 Yr Flood Zone Sacramento Wilton Rancheria Out of Flood Zone Yolo Yocha Dehe Wintun Nation (Rumsey Rancheria) Out of Flood Zone

2.0 Geography

Sacramento River Region The Sacramento River hydrologic region includes the northern half of the Central Valley which includes our planning area. The Sacramento River drains through the Sacramento‐San Joaquin Delta. The region is bounded by the Sierra‐Nevada Mountains, Coast Range, Cascade Range, and Trinity Mountains. Flooding in this region is predominantly caused by runoff from either major winter storm events or snowmelt. While massive dams and levee systems have significantly reduced this region’s historic flood problems, the area remains vulnerable to flooding along small streams due to levee failures and in urban drain areas dependent upon pumping stations. Rivers include the Sacramento, Feather, American, Yuba, San Joaquin, Cosumnes, and Mokelumne Rivers along with several creeks and streams.

See The Operational Area Annex for detailed information on each of the ten counties in the planning area. Figure B-2: California Hydrologic Regions

The Delta Region The Sacramento-San Joaquin River Delta and Suisun Marsh, collectively referred to as the Delta Region, is the largest estuary in the western United States. The Delta Region is home to numerous plant and animal species, some of which are found nowhere else. The Delta Region is also the hub of California’s water supply system. Diversions from the Delta provide water for

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about 25 million people and about 3 million acres of farm land. Key transportation, transmission and communication lines cross the region. The region is also important to recreation and tourism. The rich soils of the Delta islands support a highly productive farming industry. See figure B-3 for a map of the Delta.

Much of the land in the Delta Region is below sea level and is protected by a fragile system of levees. Many of the region’s 1,100 miles of levees were built in the late 1800s and early 1900s without using modern engineering practices. The Delta Region’s levees are critical for protecting the various assets, resources, uses and services that Californians obtain from the region.

A unique feature of the Delta Region is that much of its land is made up of highly organic soils, commonly referred to as “peat soils”. Peat soils are very fertile and support an abundant agricultural harvest. Over time, agricultural practices have caused the land surface of Delta islands to subside. During the past century, subsidence has lowered the land surface of some Delta islands to as much as 25 feet below sea level, as shown in Figure B-4. Land that is below sea level requires levees to hold back water 365 days a year. Since 1900, levee failures during high water and during dry weather have caused Delta islands to be flooded a total of 158 times. Some islands have been flooded and recovered multiple times. A few islands, such as Franks Tract, have never been recovered. Franks Tract is located in the central Delta.

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Figure B-3: Map of the Sacramento-San Joaquin River Delta and Suisun Marsh (The Delta Region)

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Figure B-4: Surface Elevation Map of the Delta Region

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Risks to the Delta A massive failure of the Delta Region’s levee system would have significant adverse effects on the Delta Region and California’s economy. Levee failure risks evaluated in the Delta Risk Management Strategy (DRMS) Executive Summary Report (2009) analysis include seismic, high water and dry-weather levee failures.

Seismic Risks Seismic risk in the Delta Region is characterized as moderate to high because of many active faults in the San Francisco Bay Area. Figure B-4 illustrates the locations of faults in and near the San Francisco Bay Area and the Delta Region. Seismic activity during the last 100 years is significantly less than what was experienced during the 1800s and the first part of the 1900s. Seismic experts predict increased seismic activity in the future similar to that which occurred up to the first part of the 1900s.

Figure B-5: Faults and Seismic Sources in the Vicinity of the Delta Region

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The U.S. Geological Survey estimates that an earthquake of magnitude 6.7 or greater has a 62 percent probability of occurring in the San Francisco Bay Area between 2003 and 2032. Such an earthquake is capable of causing multiple levee failures in the Delta Region which could result in fatalities, extensive property damage and the interruption of water exports from the Delta for an extended period of time. Potential earthquakes on the Hayward, Calaveras or San Andreas faults pose the highest risk to Delta Region levees.

Probability of Multiple Levee Failures: A major earthquake can cause extensive damage to large sections of levees on multiple islands at the same time. As a result, many islands could be flooded simultaneously. For example, there is a 40 percent probability of a major earthquake causing 27 or more islands to flood at the same time in the 25-year period from 2005 to 2030.

According to the DWR Delta Emergency Operations Plan Concept Paper (April 2007), if an earthquake occurs that causes strong ground shaking in the Delta, the locations most likely to be affected are the western and southwestern portions of the Delta. These areas are closer to potential earthquake sources and are therefore more likely to experience more intense shaking. Flooding of these islands is also more likely to interfere with fresh water conveyance to export pumps. In previous work by DWR, Sherman Island was identified as the island with the weakest levees relative to seismic shaking and therefore the island with the greatest susceptibility to a seismically driven failure. Other islands in the western and central Delta were also found to have a medium to medium-high susceptibility to failure. Accordingly, a scenario such as the one shown in Figure B-5 could result from a strong earthquake in or near the Delta. Table B-6 below shows the islands that would be flooded in such a scenario, with each island’s number of breaches indicated.

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Figure B-6: Multi-Island Failure Scenario – Levee Breach Locations

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Table B-5: Examples of Flooded Islands and Number of Breaches

Island # of Breaches Island # of Breaches Bacon 2 McDonald 1 Bethel 2 Orwood 2 Bouldin 1 Palm 2 Bradford 1 Quinby 1 Brannon/Andrus 2 Sherman Island 20 Byron 1 Twitchell 1 Holland 2 Upper Jones 1 Jersey 4 Venice 1 Lower Jones 1 Victoria 1 Mandeville 1 Webb 1 Source: URS, 2007

Export Disruption: Earthquake damage to levees and to the islands they protect could take years to repair following a major earthquake. The total economic cost and impact of multiple levee failures due to a major earthquake in the Delta Region could be tens of billions of dollars. One significant impact of levee failures would be to the state’s water supply. For example, if 20 islands were flooded as a result of a major earthquake, the export of fresh water from the Delta could be interrupted for about a year and a half. Water supply losses of up to 8 million acre-feet would be incurred by State and federal water contractors and local water districts.

Impacts to Water Quality: Though not specifically analyzed in the Delta Risk Management Strategy Project, it is reasonable to conclude that, if subsided Delta islands are flooded due to levee breaches, significant amounts of dissolved organic carbon (DOC) would be released into Delta waters from the highly organic peat soils on these islands. Disinfectants used during the drinking water treatment process react with DOC to produce disinfection byproducts in treated water. Many of these chemical byproducts can increase cancer risks or cause other health effects.

Other water quality problems resulting from island flooding include increased algae blooms. Algae blooms can complicate drinking water treatment processes and can adversely affect some aquatic species.

Some soils in the Delta Region contain moderate levels of mercury due, among other things, to historical gold mining activities that occurred upstream of the Delta during the Gold Rush. Mercury in soils can, under certain circumstances, be converted to the highly toxic methylated form when islands are flooded. Methylated mercury can accumulate in the food chain potentially affecting fish. Humans and animals that consume fish contaminated with methylated mercury are at risk of poisoning.

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Public Health and Safety Consequences: The Delta levees most likely to fail due to earthquakes are generally located in the central-west area of the Delta. Their failure will cause rapid flooding and leave little time for evacuation. The greatest immediate public safety concern is for the people working and living on Delta islands, and for people traveling through the Delta on various roads and highways. There is a 40 percent probability of 90 or more fatalities in the Delta from levee failures due to a seismic event in the 25-year period from 2005 through 2030. The expected fatalities from earthquake related island flooding is high due to the lack of warning for earthquakes and because of the rapid rate of flooding likely to occur after an earthquake.

High Water Risks Although earthquakes pose the greatest single risk to Delta Region levees, winter storms and related high water conditions are also a serious risk. High water in the Delta

Region can overtop levees. High water also increases the hydrostatic pressure on levees and their foundations, causing instability. The risk of through-levee and under-levee seepage failures increases as well.

Most levee failures in the Delta Region have occurred during winter storms and related high water conditions, often in conjunction with high tides and strong winds. Considering the probability of all high water-related levee failures under current conditions and existing levee maintenance programs, about 140 levee failures are expected to occur in the Delta over the next 100 years (compared with 158 during the past 100 years). This corresponds to an average rate of 1.4 levee failures per year. Note that levee failure does not mean a sudden, catastrophic loss if a levee but rather the levee could experience issues such as erosion, boils, or some other less catastrophic issue.

Probability of Multiple Levee Failures: Depending on the severity of the high water conditions, tides, wind and other factors, multiple levees could fail during a single high water event.

Export Disruption: High water-related levee failures pose less risk to water supplies than failures from earthquakes. The Delta would likely be receiving large volumes of fresh water inflow from upstream when high water-related levee failures occur. As long as levee breaches are managed appropriately, and repairs are completed when fresh water inflows into the Delta are still relatively high, no long-term water supply export disruptions should occur. Also, the size and number of levee failures due to high water events are expected to be less than earthquake-related failures. With fewer and smaller failures, repairs would take less time.

Impacts to Water Quality: Impacts to water quality from high water-related levee failures are expected to be less than from a major earthquake. Salt, DOC and methylated mercury concentrations during and after high water-related levee failures are expected to be lower because of greater freshwater inflows.

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Public Health and Safety Consequences: The primary public safety concern from high water- related levee failures is for the people living and working on Delta islands, and for people traveling through the Delta on roads and highways. There is about a 40 percent probability of 80 fatalities or more in the Delta Region from levee failures due to a high water event during the 25-year period from 2005 to 2030. Some densely populated areas, such as the Sacramento Pocket Area and West Sacramento, are especially at risk of fatalities.

Dry-Weather Risks Dry-weather levee failures, also known as sunny-day events, occur occasionally in the Delta Region. Individual failures can be attributed to factors such as burrowing animals, preexisting weaknesses in levees and their foundations, slow deterioration of levees over time and other circumstances. High astronomical tides can also be a factor in dry-weather levee failures. The most recent example of a dry-weather failure is the June 2004 Upper Jones Tract levee breach. The total cost of damages and island recovery efforts was well over $50 million.

Historical levee failures were used as the model to estimate the future rate of dry-weather levee failures in the Delta Region. Under business-as-usual practices, the Delta is expected to have about 10 dry-weather levee failures during a 100-year period. The Suisun Marsh is expected to have approximately four dry-weather levee failures during the same period.

Combined Risks The combined risk of an individual island being flooded due to earthquakes, high water and dry- weather events can be estimated. Considering the probability of levee failures from all hazards under business-as-usual practices, the expected annual probability of island flooding is illustrated in Figure B-7. Figure B-7 also shows that islands in Suisun Marsh and the western and central Delta are the most vulnerable.

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Figure B-7: Mean Annual Probability of Levee Failure from Combined Risk of Earthquakes, High Water and Dry-weather Failures (2005 Conditions)

Source: Delta Risk Management Strategy Risk Report

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3.0 Threat

Winter storms that could produce catastrophic flooding occur generally in the winter months of January and February. The last massive statewide winter storm occurred in the winter of 1861- 1862. However, massive storms are a recurring feature of the state, the source of rare but inevitable disasters. Over the last decade, scientists have determined that the largest storms in California are the product of a phenomenon called Atmospheric Rivers.

Atmospheric River Atmospheric River (AR) storms occur several times a year around the United States. Jets of warm, moist air and high wind originate over the mid-latitude North Pacific Ocean, transporting moisture to California, where much of the moisture turns to rain and snow. While ARs come in many shapes and sizes, those that contain the largest amounts of water vapor, the strongest winds, and stall over watersheds can create extreme amounts of precipitation and flooding. ARs could drop inches of rain on the state daily for a period of weeks, damaging infrastructure, overtopping levees, inducing mud slides/mud flows, and causing mass evacuations and overall catastrophic damage to multiple regions.

Figure B-8: Atmospheric River

Pineapple Express is a non-technical term for a meteorological phenomenon characterized by a strong and persistent flow of atmospheric moisture and associated with heavy precipitation from the waters adjacent to the Hawaiian Islands and extending to any location along the Pacific coast of North America. A Pineapple Express is an example of an atmospheric river, which is a more general term for such narrow corridors of enhanced water vapor transport at mid-latitudes around the world.

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El Nino/La Nina El Niño is characterized by unusually warm ocean temperatures in the Equatorial Pacific, as opposed to La Niña, which characterized by unusually cold ocean temperatures in the Equatorial Pacific. El Niño produces consequences for weather around the globe.

Among these consequences is increased rainfall across the southern tier of the US and in Peru, which has caused destructive flooding, drought in the West Pacific (Hawaii), and is sometimes associated with devastating brush fires in Australia. Figure B-9: The El Nino Phenomenon

El Niño is often confused with an Atmospheric River (ARs) or a “Pineapple Express.”

Coastal Hazards Bay waters experience two low tides and two high tides of unequal height each day. King Tides are unusually high but predictable astronomical tides that occur approximately two to four times per year, generally between December and February. In additional, there are short term factors that elevate the waters of the bay shorelines such as El Nino, storm surge and waters and freshwater inflow from the Delta. When one or more of these factors combine to raise Bay waters above predicted tide levels, the result is a temporarily higher water level called an extreme tide. Extreme tides can reach several feet higher that King Tides and result in damaging coastal floods.

Climate Change Considerations Earth’s climate is always changing; however, the climate change we are tracking today is being reported as different from previous climate change in both its rate and magnitude. Though data surrounding climate change continues to be collected and knowledge about this topic is still evolving, the effects of climate change are listed here for consideration in advance of a catastrophic flooding event. The noted, and/or projected, effects of climate change to be considered include the following:

 Warmer air temperatures:

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Air and ocean temperatures are expected to increase as climate change continues to occur. Longer occurrences of warmer temperatures would likely exacerbate the frequency and intensity of droughts. Droughts not only increase the demand for water, but also kill off vegetation on hillsides, further increasing the likelihood and frequency of fires. Fires further eliminate vegetation, which helps to secure soil to hillsides. Flooding after fires will cause mudflows and landslides occurring, increase sediment loads and debris flows, and potentially impact water quality.

Warmer temperatures could also cause snow in the Sierra Nevada’s, a major contributor to California’s water supply, to melt at a faster rate – causing an increase in river flows and flooding occurrences farther downstream. California’s current water systems are designed and operated to support a balance between water storage for the dry months and flood protection during the winter/spring, when heavy rainstorms, runoff, and snowmelt can cause downstream flooding. Snowmelt running off earlier than projected due to warming temperatures will leave less water stored for the dry months, and may affect California with more frequent and/or more extensive flooding.

A smaller percentage of precipitation falling as snow instead of rain could also occur. Climate change is anticipated to bring warmer storms, resulting in less snowfall at lower elevations and increasing the snowmelt rate at higher elevations.

 Sea level rise: Warmer temperatures are also causing sea levels to rise, increasing the likelihood that ARs could occur more frequently and more intensely. AR cycles over the Pacific Ocean are a key factor in supporting California’s wet year and drought year cycles. Intensification and increased frequency of these storms as a result of climate change could mean stormier wet years and even drier or increased periods of drought years.

Changes in water temperatures and sea level rise will affect fish species and ecosystems, disturbing the overall balance of the water. Delta saltwater intrusion is more likely with rising sea levels – affecting the Delta ecosystem and the Delta water conveyance system used for agricultural and population purposes. Saltwater intrusion into groundwater could also occur with higher tides, storm surges and inland flooding. All are anticipated to increase as part of the effects of climate change.

 Other considerations: Population increases to projected inundated and flooded areas also mean more people affected, more people hurt and/or killed by the flood/storm, more people and/or animals to evacuate, etc.

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With changes in California’s hydrology due to climate change, what is currently considered a 100-year flood may strike more often – increasing the risk factor. As noted in the Safeguarding California Plan, climate change is expected to increase the frequency and the magnitude of more severe weather events which will lead to an increase in the magnitude of the 100-year event. For example, a previous 100-year estimated event is now a 70-year event. In addition, the Plan noted that climate change is expected to increase the frequency of 100-year storms/floods in any year, resulting in multiple 100- year storms or floods that occur in a single year. Current flood protection facilities and flood flow facilities, originally designed to meet or exceed 100-year flood risk, would need to be upgraded to take into consideration the increased threat.

Flood waters can also contain household, industrial waste, agricultural chemicals, sewage, and human/animal waste, affecting human and animal health and safety. Flooding and heavy rainfall can wash chemicals from contaminated soils, farms, and streets into drinking water supplies, further causing a health and safety concern for affected populations.

ARkStorm ARkStorm is a hypothetical storm constructed from aspects of the January 1969 and February 1986 historical floods. Designed by the US Geological Survey Multi-Hazard Team, ARkStorm was developed for the purpose of raising flood awareness. The resultant volume of floodwaters from such a storm is estimated to be similar to the 1862 flood. ARkStorm is an extraordinarily rare event with an estimated annual chance of occurrence 1/1000. While unlikely, such events are occurring in other parts of the county, have occurred in California in the past and may occur again in the future.

4.0 Flood Infrastructure Impacts

Flood Control System Northern California is protected from flooding by a system of levees, weirs, bypasses and dams. The Central Valley Flood Protection Board or DWR have provided assurances for part of this system that was constructed under State- and federally-authorized projects. This system is generally known as the State Plan of Flood Control (SPFC) and is defined in California Water Code Section 9110. The SPFC includes approximately 1,600 miles of levees, five major weirs on the Sacramento River, seven major pumping plants, and environmental mitigation areas. The counties listed in the NCCFRP are protected in part by the SPFC, as well as many other non- SPFC levees, dams, and relief structures.

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Levees Levees are used to protect land from peak flood levels and/or to protect land that is below sea level. Many of the levees protecting the 10-county area were initially built by farmers and local land owners to protect their homes, property, and families. Over the years, these levees have been improved, evolving into the flood control system seen today.

There are two types of levees. The first type of levee, such as the Sacramento River near Sacramento, is designed to withstand peak flood levels that are caused by rapid snow melt or intense rainfall. The second type of levee, such as the levees throughout the Sacramento-San Joaquin River Delta region, is designed to withstand nominal water levels on a continuous basis as well as peak flood levels.

Table B-6 below depicts both State Plan of Flood Control (SPFC) and Non-State Plan of Flood Control levee miles in the 10 county planning area. For more information on the State Plan of Flood Control see Flood Operations Annex C.

Table B-6: Levee Miles in Planning Area

SPFC Levee Lengths Non-SPFC Levee Lengths Total Levee Lengths County (miles) (miles) (miles) Butte 111.4 167.9 279.3 Colusa 96.6 238.0 334.6 Contra Costa 0.0 243.3 243.3 Glenn 30.7 152.7 183.4 Sacramento 184.5 272.3 456.8 San Joaquin 175.4 733.3 908.7 Solano 86.1 525.1 611.2 Sutter 228.4 56.7 285.1 Yolo 224.6 147.5 372.0 Yuba 87.6 27.2 114.8 Total 1225.3 2563.9 3789.2

Levee Structures Figure B-10 depicts a typical levee cross section and feature terminology. Figures B-11 and B- 12 depict typical non-leveed and leveed structures with associated flood stages.

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Figure B-10: Levee Cross Section

Figure B-11: Cross Section, Typical Non-Leveed Structure

Monitor Stage – The stage (water surface elevation) at which initial action must be taken by concerned interests (livestock warning, removal of equipment from lowest overflow areas, or simply general surveillance of the situation). This level may produce over bank flows sufficient to cause minor flooding of low-lying lands and local roads.

Flood Stage – The stage (water surface elevation) at which over bank flows are of sufficient magnitude to cause considerable inundation of land and roads and/or threat of significant hazard to life and property.

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Figure B-12: Cross Section, Typical Leveed Structure

Monitor Stage – The Stage at which patrol of flood control project levees by the responsible levee maintaining agency becomes mandatory, or the Stage at which flow occurs into bypass areas from project overflow weirs.

Project Flood Stage – The Stage at which the flow in a flood control project is at maximum design capacity (U.S. Corps of Engineers "Project Flood Plane"). At this level there is a minimum freeboard of 3 feet to the top of levees.

Danger Stage – The Stage at which the flow in a flood control project is greater than maximum design capacity and where there is extreme danger with threat of significant hazard to life and property in the event of levee failure. This is generally 1 foot above project flood stage.

Figure B-13: Sutter Bypass Right Bank (West) Levee Break – January 5, 1997

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Flood Severity Definitions Once a river reaches flood stage, the flood severity categories used by the National Weather Service (NWS) include minor flooding, moderate flooding, and major flooding. Each category has a definition based on property damage and public threat.

 Minor Flooding - minimal or no property damage, but possibly some public threat or inconvenience  Moderate Flooding - some inundation of structures and roads near streams. Some evacuations of people and/or transfer of property to higher elevations are necessary.  Major Flooding - extensive inundation of structures and roads. Significant evacuations of people and/or transfer of property to higher elevations.

The impacts and severity of flooding vary locally. For each NWS river forecast location, flood stage and the associated severity categories are established in cooperation with public officials. The impact and severity of flooding at a given stage is not necessarily the same at all locations along a river reach due to varying channel and bank characteristics, or the presence of levees on portions of the reach.

Levee Inspections DWR conducts annual inspections of levees in the State Plan of Flood Control. Table B-7 below depicts the critical points of interest and the serious points of interest identified by DWR in their 2015 Annual Inspection and Local Maintaining Agency Report. “Critical” means that the site is likely to fail in the next high water event. “Serious” means that the site may fail in the next one or two high water events and, if not repaired, may turn critical. Vegetation deficiencies make up the majority of deficient levee miles for 2015, followed by a significant amount of erosion, animal control and crown surface issues. The remainder of deficient miles comes from encroachments and other items. Note that DWR does not conduct annual inspections of the Non- State Plan of Flood Control levees.

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Table B-7: State Plan of Flood Control - Levee Vulnerabilities

Critical Points of Interest Serious Points of Interest County Totals Erosion Seepage Stability Other Erosion Seepage Stability Other

Butte 0 0 0 0 1 2 2 0 5 Colusa 3 3 2 0 9 4 1 1 23 Contra N/A N/A N/A N/A N/A N/AN N/A N/A N/A Costa* Glenn 1 0 0 0 2 0 0 1 4 Sacramento 4 12 2 0 29 11 4 0 62 San Joaquin 7 24 1 0 15 34 0 0 81 Solano 1 2 1 0 20 3 1 0 28 Sutter 2 13 1 0 17 9 3 0 45 Yolo 2 2 2 0 29 10 7 0 52 Yuba 0 2 0 0 0 0 0 0 2 Totals 20 58 9 0 122 73 18 2 302 Source: DWR Inspection and Local Maintaining Agency Report of the Central Valley State-Federal Flood Protection System Report (2015) *Contra Costa County does not have any levees in the State Plan of Flood Control area.

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Figure B-14 below illustrates the location of the critical and serious points of interest.

Figure B-14: Levee Vulnerability Overview Map

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Weirs Weirs are concrete structures built into lowered sections of levees that allow flows in excess of the downstream channel capacity to escape into a bypass channel or basin. There are five major weirs on the Sacramento River: Moulton Weir, Colusa Weir, Tisdale Weir, Fremont Weir, and Sacramento Weir. All but the Sacramento Weir are fixed structures that river water flows over when it reaches a particular level. The Sacramento Weir has 48 gates that are manually opened and closed when predetermined criteria are met.

Figure B-15: Basic Diagram of a Concrete Weir Structure

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Figure B-16: Weirs

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5.0 Dams

There are approximately 207 dams in the planning area. Dam operators will take actions necessary to protect their dams. Controlled releases of large quantities of water from reservoirs could result in downstream impacts. Damage could be greater in spillways that sit untested for years and are then subjected to continuous water flows for an extensive period of time.

Approximately 45 dam failures have occurred in California since 1883, the last failure in 1965. All occurred in dams built before 1950.

Table B-8: Dams by Type in Planning Area

Total # Dams in Flood Non- County of Jurisdictional Federal Illegal FERC Zones Jurisdictional Dams 100 Yr 500 Yr Butte 35 24 11 0 0 10 4 0 Colusa 10 2 4 4 0 0 1 0 Contra Costa 40 25 13 2 0 1 11 0 Glenn 9 4 3 2 0 0 2 0 Sacramento 29 19 8 2 0 0 10 0 San Joaquin 19 7 11 1 0 1 2 1 Solano 32 18 11 2 1 0 7 1 Sutter 1 0 1 0 0 0 1 0 Yolo 6 2 4 0 0 0 2 0 Yuba 26 8 13 5 0 4 1 0 Total 207 109 79 18 1 16 41 2 Source: CA Division of Safety of Dams and Cal OES

“Jurisdictional Dams” (regulated) are defined by statutes and rules as an artificial barrier for the impounding or diversion of water either 25 feet or more in height or having a storage capacity of more than 50 acre-feet.

“Non-Jurisdictional Dams” (unregulated) are defined as dams that are less than 25 feet high (from downstream toe) and 15 acre-feet of storage or less than 6 feet high (from downstream toe) with 50 acre-feet of storage.

“Federal Dams” are defined as any dam with an artificial barrier, including appurtenant works, which impounds or diverts water, and which (1) is 25 feet or more in height from the natural bed of the stream or watercourse measured at the downstream toe of the barrier or from the lowest elevation of the outside limit of the barrier if it is not across a stream channel or watercourse, to the maximum water storage elevation or (2) has an impounding capacity at maximum water storage elevation of 50 acre-feet or more. The US Bureau of Reclamation (BOR) is responsible for overseeing all federal dams in California that do not have a hydropower component.

“Illegal Dams” are dams that are of jurisdictional size, but do not meet DWR/DSOD engineering requirements and/or are not paying an annual fee. If the existence of an illegal dam comes to DSOD attention, they would generally begin inspecting it every 12-18 months (like all other jurisdictional dams) and work with the owners to bring their dam into compliance.

“Federal Energy Regulatory Commission (FERC) Dams” are dams that can produce hydropower and are co- regulated with the California Division of Safety of Dams.

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There are two major dams and reservoirs in the planning area:

 Oroville Dam (Butte County) – Oroville Dam, operated by the CA Department of Water Resources, is the centerpiece of the State Water Project (SWP) and is also its largest water storage facility. Located about 70 miles north of Sacramento at the confluence of the three forks of the Feather River, Oroville Dam is an earthfill dam (consisting of an impervious core surrounded by sands, gravels, and rockfill materials) that creates a reservoir that can hold 3.5 million acre-feet of water. Besides storing water, the dam also protects downstream residents from the flood prone Feather River which is the main feeder of the SWP. Stored water released from Oroville Dam flows down the Feather River and enters the Sacramento River system near Verona. When high inflows occur between October and May, water is held in Lake Oroville temporarily until downstream channels are capable of handling them without flooding. Oroville Dam alone provides 750,000 acre-feet of flood control storage, and has been credited with minimizing damage during floods that have hit the Feather River watershed in virtually every decade since the dam’s construction in the 1960s. About one-third of the water released from the reservoir goes to uses between Oroville and the Sacramento San Joaquin Delta. When it reaches the Delta, Feather River water blends with runoff from other watersheds of the Sacramento and San Joaquin valleys. At Barker Slough, in the North Delta, up to 76,781 acre-feet of water can be diverted into the North Bay Aqueduct, a 27.6-mile underground pipeline that provides water to augment local supplies in Napa and Solano counties.  Folsom Dam (Sacramento County) – Folsom Dam and reservoir, operated by the U.S. Bureau of Reclamation, is located on the American River and is a part of the State Water Project in the central valley. The Folsom reservoir catches runoff from the extensive American River watershed and is a key flood control structure protecting the Sacramento metropolitan area. Located about 25 miles northeast of Sacramento along the American River, Folsom Dam is a 340 foot high concrete dam flanked by long earthen wing dams extending to high ground at either end and holds over a million acre-feet of water in Folsom Lake. Although its primary function is flood control, Folsom stores water for irrigation and domestic use and electrical power generation. There are three dams outside of the planning area worthy to note. Friant Dam, a BOR dam in Fresno County, forms Millerton Lake and regulates the San Joaquin River, which flows through Stockton. The freeboard on the San Joaquin is much shallower than on the American, Feather or Sacramento rivers, and if a major storm were to hit Central California, Friant's small-ish 500,000 acre-foot capacity would be exceeded quickly, requiring extraordinary releases to prevent

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damage to the dam. This, in turn, would result in massive flooding along the river pathway (mostly agriculture land) and would affect smaller communities along the way.

In a similar vein and less likely, but more troublesome, is New Melones Dam in Tuolumne County on the Stanislaus River. New Melones is an earth-filled structure that is protected from overtopping by an emergency overflow spillway cut into rock. It only reached that level twice since 1983, but both times its uncontrolled releases scoured the Stanislaus River bed and banks all the way down to where it meets the San Joaquin River southwest of Ripon, affecting agricultural land and small towns in Stanislaus and San Joaquin Counties.

Shasta Dam in Shasta County is operated by the US Bureau of Reclamation and stands among the world’s largest dams. Located on the Sacramento River 12 miles north of Redding near Shasta Lake City, Shasta Dam is the keystone of the federal Central Valley Project. Water is transported 450 miles from Lake Shasta in Northern California to the San Joaquin Valley. Loss of Shasta Dam would mean a loss of salinity control in the delta, which would result in a loss of State Water Project and Central Valley Project water delivery to Southern California.

Additionally, the DWR DSOD has identified 38 dams that are considered problematic due to varying degrees of deficiencies. Problematic is defined as dams that would fail under dynamic loading conditions like an earthquake or Probable Maximum Flood (PMF) conditions. Specifically, DWR would classify a dam whose spillway could not pass the PMF without overtopping as being structurally deficient. Dams on this list are currently under DSOD order to restrict the elevation at which water can be stored in their reservoirs. There are three problematic dams in the planning area. Two are in Butte County and 1 is in Sacramento County.

Controlled releases of large quantities of water from reservoirs could cause flooding in downstream creeks, channels, and floodplains. This could also cause minor spillway damage or erosion in downstream channels. Damage could be greater in spillways that sit untested for years and are then subjected to continuous flow for an extensive period.

6.0 Infrastructure

Transportation Add short description

See Annex ?? for detailed information on Transportation infrastructure.

Energy Add short description

See Annex ?? for detailed information on Energy infrastructure.

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Water/Wastewater Add short description

See Annex ?? for detailed information on Water/Wastewater infrastructure.

State and Local Government Add short description

See Annex ?? for detailed information on State/Local Government infrastructure.

Agriculture Add short description

See Annex ?? for detailed information on Agriculture infrastructure.

7.0 Flood Monitoring, Analysis and Warning

California has a very complex and sensitive water system, particularly the part of the system that northern California relies on. The system is dependent on a few major winter storms during the flood season (October 15 – April 15) to build snowpack and help ensure that water levels in the State’s reservoirs are at adequate levels to support usage for population, agriculture, and recreation. As warmer temperatures start affecting the state, the rate at which the snowpack melts can have a significant effect on the State’s water system. Temperatures that warm up too quickly for a consistent period of time can cause the snowpack to melt at too fast a rate. Depending on the levels of reservoirs and downstream lakes, creeks, and rivers, this increased runoff can overwhelm the system, put increased stress on levees and other aspects of the flood control system, and potentially cause flooding.

A large-scale weather event can cause flooding in multiple counties at once – necessitating the use of State and federal resources and support once local capabilities has been overwhelmed. This plan uses what is referred to as progressive phasing, as a large-scale weather event is not like an earthquake incident where the earthquake occurs and response begins immediately. Flooding, particularly when caused by a large-scale weather event, is typically able to be prepared for ahead of time by monitoring weather reports and warnings and establishing early and consistent communication between areas anticipated to be affected by flooding. Monitoring occurs in ALL phases of a flood event. The following are important factors, in no particular order, to consider before, during, and after a flood event.

Snow Levels: Current snow levels are important because weather and air temperatures affect snowmelt rates. The more snow you have in the Sierra Nevada Mountains, the more potential snowmelt to fill up reservoirs. Snowmelt rates are also important, as they can contribute to

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additional flooding downstream and add stress to water support infrastructure (such as levees and dams).

Snow level data has been collected by various agencies over the years, and the California Cooperative Snow Survey program was formally established by State Legislature in 1929. The Legislature determined that DWR would be the coordinator for this program (Water Code Section 228). The Snow Survey program is an example of State, federal, local, and private cooperation, and more than 50 State, national, and private agencies pool their snow collection data efforts each year. Data collected is transmitted to DWR, and can include snow pack water content data, statistics on precipitation, runoff, and other hydrologic data.

DWR coordinates the California Cooperative Snow Survey program which collects snow data to help with runoff forecasting. Bulletin 120, published by DWR on a monthly basis from February through May, contains forecasts of the volume of seasonal runoff from the State’s major watersheds, and summaries of precipitation, snowpack, reservoir storage, and runoff in various regions of the State. Bulletin 120 can be found at: http://cdec.water.ca.gov/snow/bulletin120/index.html.

Reservoir conditions and operations: Capacity and levels of reservoirs are an important consideration to monitor both prior to, and in the event of, an atmospheric river event. The coordinated operations of reservoirs throughout the state works to strike a balance to ensure appropriate water levels are maintained in reservoirs throughout the State. Releases of water from reservoirs, including amounts and rates, will affect water conditions downstream of the reservoirs. These releases would affect areas downstream that may already be flooded and/or in danger of flooding, as well as put additional stress on levees and water storage facilities.

The Forecast-Coordinated Operations (F-CO) program focuses on flood control reservoirs in the Central Valley. Core partner agencies include DWR, the National Oceanic Atmospheric Administration (NOAA), and the U.S. Army Corps of Engineers (USACE). The core partners work with and coordinate with all reservoir operators to improve downstream flood protection without impacting the water supply of upstream reservoirs. This coordination is important to help reduce flood peaks and provide longer lead time for emergency response managers. Information about reservoir operations and reports, as well as dam conditions, can be found on the California Data Exchange Center (CDEC) at: http://cdec.water.ca.gov/reservoir.html.

Burn areas: Areas affected by fires often have little vegetation left, exposing the soil to erosion, making the burn area vulnerable and increasing the chances of flooding and debris flows during periods of heavy rain. Sediment from flooding from a burn area can move downstream and damage infrastructure and pose a danger to people and animals. Debris flows can pose a significant threat to people, property, and infrastructure. The debris from a flooded burn area can also fill reservoirs, lakes, streams, channels, etc., further stressing components of the flood control system and diminishing the capabilities of the system. Information about burn areas for

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the past 3 years can be found on the California-Nevada River Forecast Center (CNRFC) webpage at: www.cnrfc.noaa.gov.

Status of levees and levee projects: The State boasts over 13,000 miles of levees, with over 3,790 miles of those levees being located in the planning area. Local agencies and county emergency managers typically partner with Reclamation Districts (RDs), Local/Levee Maintaining Agencies (LMAs), DWR, USACE, and other applicable agencies to monitor the status of levees throughout the region. Levee patrols and levee assessments enable these agencies to gather information about each levee such as; known vulnerabilities, historical data, status of any projects and activities on the levee.

Weather/Hydrology Briefings: Weather and hydrology briefings are provided at the FOC in Sacramento by staff from both the Division of Flood Management and the National Weather Service’s CNRFC. These briefings are generally scheduled from mid-October through mid- April, known as the “flood season”, and the frequency of which may range from once a week to more often depending on hydrologic and weather conditions. The briefings include in-depth meteorological analysis and hydrologic impacts (current and/or anticipated). More information, including how to receive access to the Weather and Hydrology briefings, can be found at: http://www.water.ca.gov/floodmgmt/hafoo/fob/focs/weatherbriefing.cfm.

Flood Forecast and Warnings The National Weather Service, Hydrologic Services Program provides river and flood forecasts and warnings for the protection of lives and property. Eleven Weather Forecast Offices located in Medford (OR), Eureka, Reno and Las Vegas (NV), Sacramento, Monterey, Hanford, Oxnard, San Diego, Phoenix (AZ), and the California-Nevada River Forecast Center. Both Sacramento offices are co-located with the FOC at the Joint Operations Center.

Below are weather products from the NWS:

 Advisory (Abbreviated ADVY): Highlights special weather conditions that are less serious than a warning. They are for events that may cause significant inconvenience, and if caution is not exercised, it could lead to situations that may threaten life and/or property.  Flood Watch: A watch is used when the risk of a hazardous weather or hydrologic event has increased significantly, but its occurrence, location, and/or timing is still uncertain. It is intended to provide enough lead time so that those who need to set their plans in motion can do so.  Flood Warning: A warning is issued when a hazardous weather or hydrologic event is occurring, is imminent, or has a very high probability of occurring. A warning is used for conditions posing a threat to life or property.

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8.0 Flood Monitoring Tools

California Data Exchange Center (CDEC) This data exchange program involves the automated transfer and receipt of data and information via network connections. Programmers for CDEC install, maintain, and operate an extensive hydrologic data collection and exchange network, which includes automatic snow reporting gages for the Cooperative Snow Surveys Program and precipitation and river stage sensors for flood forecasting. CDEC provides a collection point for a vast inventory of information. CDEC electronically exchanges real-time data with the following cooperative agencies:

 National Weather Service (NWS)  US Army Corps of Engineers (USACE)  United States Bureau of Reclamation (USBR)  United States Geological Survey (USGS)  California Department of Fish and Wildlife (DFW)  DWR (including the Division of Operations and Maintenance, Division of Integrated Regional Water Management, and Division of Environmental Services)  Sacramento Municipal Utility District (SMUD)  Pacific Gas and Electric (PG&E)  East Bay Municipal Utility District (EBMUD) A few local agencies and counties also have their own gages and hydrologic resources that they monitor during a weather/flood event. Some of this information is available to the public on either the county or local water agency websites. See Flood Operations and the Operational Area Annex for specific river gage information.

Valuable information is created from the data and presented in a variety of formats including maps, plots, charts, and publications. This information is available to the cooperators, public and private agencies, news media, and the general public. Data collected by CDEC enables forecasters to prepare flood forecasts and water supply forecasts; reservoir and hydroelectric operations to schedule reservoir releases; flood emergency personnel to prepare and disseminate flood hydrology data and reports; and water suppliers to anticipate water availability. The information provided on CDEC also supplements information collected by the California Nevada River Forecast Center (CNRFC) to help fulfill CNRFC’s mission of flood forecasting.

Real-time data is collected from remote data stations via the Geostationary Operational Environmental Satellite (GOES). Real-time data includes river stages, reservoir information,

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precipitation, snow water content, temperature, water quality, and full weather data. For more information on CDEC, go to: http://cdec.water.ca.gov.

California Nevada River Forecast Center (CNRFC) Operating under the National Weather Service, the CNRFC’s mission is to provide river and flood forecasts and warning for the protection of lives and property and to provide basic hydrologic forecast information for the nation’s environmental and economic well-being. The CNRFC integrates short-term weather, climate and hydrology to produce daily updates of river forecasts and water supply outlooks. Forecasts serve as the basis for river flood warnings, reservoir inflow volumes, and seasonal runoff volumes that include snowpack melt. The CNRFC offers single-value, also referred to as deterministic, forecasts out to five days. The CNRFC also provides probabilistic or ensemble forecasts that extend out to 10-days for most points and out to the end of the water year for reservoirs and other points. Appendix C lists all official NWS river forecast points in the planning area by river basin. For more information on the CNRFC, go to: www.cnrfc.noaa.gov.

Flood Emergency Management System (FEMS) FEMS provides a centralized database to support DWR’s SEMS-structured emergency operations and information/warning dissemination programs. FEMS is accessed through a DWR intranet website developed and maintained by the Flood Operations Branch. The primary purpose of FEMS is to automate and archive SEMS, Incident Command System (ICS) and other emergency operations reporting and tracking processes used at the FOC, the Eureka Flood Center, and by other DWR Emergency Response and Incident Command Teams. For more information on FEMS, go to http://fems.water.ca.gov.

Flood Emergency Response Information Exchange (FERIX) FERIX was developed by DWR to improve flood emergency preparedness, response, and recovery in California. It provides participating agencies an online system to access and exchange current flood information in real-time through Web GIS interface. It integrates geo- referenced databases, a real-time data collection and exchange system, and a decision support system supporting other DWR programs, various hydrologic and hydraulic computer models and tools, and applicable flood-related documents. For more information on FERIX, go to: http://ferix.water.ca.gov.

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9.0 Essential Elements of Information (EEI)

EEIs are essential information requirements needed to help inform decisions. EEIs provide context, inform decision making, and contribute to analysis. EEIs are required to plan and execute an operation and to support timely, logical decisions. As a baseline reference, the EEIs in the following chart are only a starting point. This list may be refined or expanded based upon the current situation.

EEI Specific Information Required WEATHER  Projected path  Estimated rainfall amounts Forecast and Related  Arrival timing and duration Information  Wind speeds and duration  High / Low Tide information and timing  Severe Weather Advisories, Watches, and Warnings  Forecast flooding information River Forecast &  Projected duration of flooding Flooding Information  Remote Sensors  Flood / Flow Gauges Extended Weather  What is the projected weather post incident  What are the response implications for the whole community  Demographics of severe wind/storm area  Pre-landfall remote sensing (“Before” pictures) if major flooding is expected Pre-landfall Information  Boundaries of area evacuated  Estimated percentage of population evacuated pre-landfall  Critical facilities in wind/flood area  Who is coordinating predictive modeling? Predictive Modeling  What data inputs are being used?  What programs are being used? Impact Projections  What are the program biases?  Where predictive modeling outputs are available?  Potential for (or extent of) flooding  Potential for power outages  Potential for Nuclear Power Plant and surrounding area (10 miles) impacted. Hazard-specific  Number/estimate of inundated structures potentially requiring Urban Search & Rescue (US&R) information  Potential for HAZMAT release  Potential/actual damage/failures  Potential for other hazards involving most at risk populations, etc.  Flash Flood and Debris Flow potential  Have previous storms of similar magnitude affected the area?  What were the results? Historical information  What resources were provided by the Federal Government?  What were the major operational problems?  What were other critical issues?  Historical background of flooding in the area. OPERATIONS  Who and where is: o IMAT Team Leader o FCO o SCO Status of key personnel o C-RRCS o FEMA liaison to State/Tribe o Section Chiefs o Key Support Staff Status of ESF  Which ESFs are activated in the Activations o RRCS

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EEI Specific Information Required o IMAT o NRCS  Has the Governor/Tribal Leader Requested Assistance and for what and where?  Is the Governor’s/Tribal Leader’s request a normal or expedited one?  Who is completing the Regional Disaster Summary and Analysis and Recommendation?  Is there a Presidential Declaration and if so what type? Status of declarations  Which jurisdictions are included?  Which types of assistance are authorized?  Are there special cost-share provisions for Direct Federal Assistance?  When are PDAs scheduled?  Which jurisdictions will be assessed, and in what order? Major issues / activities /  What operations and assessments are agencies conducting under their own authorities? Mission Assignments of  What mission assignments have been issued? ESFs/OFAs  What is status of Mission Assignments?  What are the actual or potential resource shortfalls of the affected State or Tribe?  What are the anticipated requirements for Federal resources? Resource shortfalls  What are potential or actual Federal shortfalls?  What are potential sources for resource shortfalls?  What resources are available and where are they located?  Priorities: water, food, power, medical, heat, communications, at risk populations. Priorities for Response  What are the Federal operational priorities?  What are the State/Tribal priorities?  Are National Flood Insurance Program (NFIP) non-participating communities in the NFIP Impacts affected area?  Where repair costs are likely to be substantial (exceed 50 percent of structure value)?  What is the schedule of daily meetings and briefings? Upcoming activities  What other significant events of activities are planned or scheduled?  VIP visits  Staffing shortfalls  What Remote Sensing Mission have ESF’s undertaken under their own authority?  What remote sensing missions have the State and Local governments undertaken under Status of their own authority?  What remote sensing missions have been already tasked by RST, ERT & EST? reconnaissance  What are the available assets to provide remote sensing data? operations  What format and when will information be available?  Who is providing interpretation of incoming data?  How will data be shared? IMPACTS  Geographic locations sustaining damage  Description of extent of damage sustained  Potential for Nuclear Power Plant and surrounding area (10 miles) impacted.  Boundaries of areas evacuated  Estimated percentage of population evacuated Boundaries of Disaster  Estimated percentage of population unable to return (people with disabilities/AFN).  *Polygons/files created for development of GIS maps by one GIS unit that can be used Area by other GIS units.  **All remote sensing imagery or derived maps.  Predictive Modeling Information through HAZUS, USGS, NOAA, NWS, or CaDWR.  Locations where repair costs are likely to be substantial (exceed 50 percent of the structure value)  Disasters that span international borders Boundaries of secondary disaster  Same as above areas (inland flooding, power outages, etc) Jurisdictional  List of jurisdictions (cities, counties, tribes) affected, with maps Boundaries  Political and congressional jurisdictions affected  Is there a need for personnel protection equipment? Safety Hazards  What are the safety hazards in conducting operations?  Was a Disaster Hazard Assessment Plan (DHAP) Form 066-0-0-2 completed by all supervisors and given to Safety?

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EEI Specific Information Required  What are the State/Tribal and local priorities? Status of State/Tribal  What are the major State operations in support of the local jurisdictions? and local operations  What support is being received from other States under Emergency Management Assistance Compacts?  Are there reported or suspected hazardous material/toxic release incidents? Hazardous, toxic and  What follow up actions are planned or underway?  Are there nuclear power plants in the affected areas? radiological issues  Are there actual or potential radiological incidents?  What follow up actions are planned or underway?  Maps of evacuated population with shelters and inundation Evacuations  At risk populations (people with disabilities, transportation disadvantaged, AFN, etc.)  Maps of evacuated areas with usable roads  Are evacuation routes from Nuclear Power Plants impacted?  Debris issues on public property Debris  Debris issues on private property  Debris issues on roadways  Debris issues in waterways EHP  Types and locations of historic or natural resources affected by the flood. INFRASTRUCTURE Status of critical  Status of public water supply systems infrastructure and  Status of private water supply systems  Status of public wastewater systems facilities  Status of private septic systems Status of critical  Status of electrical power generation and distribution facilities infrastructure and  Status of Nuclear Power Plants and surrounding areas (10 miles) facilities  Number of electrically dependent persons (medical equipment or AFN).  Status of Acute Medical Care Facilities Status of critical  Status of Chronic Medical Care Facilities infrastructure and  Status of Home Health Agencies  Status of State, Tribal, and Local Health Departments facilities  Status of State/Tribal/Local EMS Systems  Status of VA Health Care Systems Status of critical  Status of local government facilities and systems o Schools. infrastructure and o Public Buildings. facilities o Government Services.  Status of Water Control Systems (Dams, Levee, Drainage Systems, Storm Water Systems) Status of critical o Current Status. infrastructure and o Projected Status. facilities o Anticipated breaching and/or overtopping and timeline. o Dam discharge rates and projected impacts. o Reservoir status. Status of critical  Status of Natural Gas and fuel pipelines infrastructure and  Estimated percentage of disruption facilities  Estimated time to restore operations  Status of all modal systems, air, sea, land, rail.  Status of major/primary roads.  Status of critical and non-critical bridges.  Status of transcontinental/regional natural gas and fuel pipelines. Status of  Status of evacuation routes. Transportation  Status of evacuation routes from Nuclear Power Plants impacted.  Status of public transit and paratransit systems.  Accessibility concerns.  Debris issues.  Anticipated impacts (snow closures, flooding potential, etc). Status of critical infrastructure and  Status of local government operations (including police, fire services and EMS) facilities Status of  Status of telecommunications service (including Internet) and infrastructure, including Commo Systems towers.

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EEI Specific Information Required  Reliability of cellular.  Service in areas affected.  Potential requirement for radio/satellite communications capability.  Status of emergency broadcast (TV, radio, cable) system and ability to disseminate accessible information to the whole community.  Status of local EOCs. Status of Emergency  Status of State EOC. Operations Centers  Status of Agency EOCs.  Location and status of Federal facilities established.

Socio-economic/  Number and type of businesses affected. Political Impacts  Number of people with disabilities and others with access and functional needs affected

SURVIVORS  Number of homes affected. Socio-economic/  Potential/estimated population affected. Political Impacts  Number of shelters open/population.  Potential shelter requirements.  Population of impacted areas.  Demographic breakdown of population including income levels.  Number/type of housing units in impacted areas. Demographics  Level of insurance coverage.  Population of those with disabilities and others with access and functional needs.  Limited English Proficiency.  Pet numbers and support requirements Donations/ Voluntary Agency  Has a Donations Hotline been established or is there a need for the Hotline?  Which Voluntary Agencies are actively involved in operations? Activities  Total number of evacuated survivors.  Number of evacuate survivors with disabilities and others with access and functional Evacuations needs.  Number of evacuees not able to return.  Shelter information o Location o Population o Shortfalls  Status of Pet Shelters o Location Shelters o Population o Shortfalls  Status of Animal/Zoo Shelters o Location o Population o Shortfalls Medical Shelters  Status of Medical Shelters  Shortfalls

Annex B: Situation/Intelligence Annex B-40 Northern California Catastrophic Flood Response Plan

Appendix A: Maps

Annex B: Situation/Intelligence Annex B-41 Northern California Catastrophic Flood Response Plan

Flood Bypass and Flood Control Features Overview

Annex B: Situation/Intelligence Annex B-42 Northern California Catastrophic Flood Response Plan

Dams Overview

Annex B: Situation/Intelligence Annex B-43 Northern California Catastrophic Flood Response Plan

Appendix B: Local Maintaining Agencies

Annex B: Situation/Intelligence Annex B-44 Northern California Catastrophic Flood Response Plan

Local Maintaining Agencies

State Plan of Flood Control Non-State Plan of Flood Control County LMA LMA LMA Name LMA Name Number Number Butte County Public NA0003 RD0833 Gridley Works MA0005 Maintenance Area 5** RD2106 Glenn and Butte Counties Rock Creek Reclamation MA0007 Maintenance Area 7** Dist Butte Sacramento River MA0013 Maintenance Area 13** Reclamation District (SRRD) ST0005 Hamilton Bend Murphy Slough at M&T ST0014 Ranch

RD0108 River Farms RD0479 Mormon Basin MA0001 Maintenance Area 1** RD1004 Moulton MA0012 Maintenance Area 12** RD2047 Colusa and Glenn Counties Colusa East Levee Sacramento ST0003 River Sacramento River West NA0016 Side Levee District

RD0799 Hotchkiss Tract RD0800 Byron Tract RD0830 Jersey Island RD2024 Orwood RD2025 Holland Tract RD2026 Webb Tract RD2036 Palm Tract RD2059 Bradford Island Contra Costa* RD2065 Veale Tract RD2090 Quimby Island RD2117 Coney Island RD2121 Bixler Tract RD2122 Winter Island Cypress Coordior/Dutch RD2137 Slough Bethel Island Municipal BIMID Improvement District

LD0001G Glenn County RD1004 Moulton LD0002 Glenn County RD2047 Colusa and Glenn Counties Glenn LD0003 Glenn County RD2106 Glenn and Butte Counties MA0005 Maintenance Area 5** RD2140 Hamilton City

Annex B: Situation/Intelligence Annex B-45 Northern California Catastrophic Flood Response Plan

State Plan of Flood Control Non-State Plan of Flood Control County LMA LMA LMA Name LMA Name Number Number Butte Creek Drainage

District Colusa Basin Drainage

District

RD0003 Grand Island RD0317 Brannan Island RD0341 Sherman Island RD0800 Cosumnes RD0349 Sutter Island RD0813 Ehrheardt Club RD0369 Libby McNeil RD1002 Glanville McCormack-Williamson RD0551 Pearson RD2110 Tract RD0554 Walnut Grove RD2111 Dead Horse Island RD0556 Upper Andrus RD0563 Tyler Island RD0755 Randall RD1000 Natomas Sacramento RD1601 Twitchell American River Flood NA0001 Control District Brannan Andrus Levee NA0002 Maintenance District NA0005 City of Sacramento Sacramento River West NA0016 Side Levee District Sacramento County NA0050 (Structures) DWR Sacramento NA0055 Maintenance Yard (Structures) MA0009 Maintenance Area 9***

RD0001 Union Island RD0002 Union Island West RD0017 Mossdale RD0038 Staten Island RD0404 Boggs Tract RD0348 New Hope Tract RD0524 Middle Roberts Island RD0403 Rough and Ready Island RD0544 Upper Roberts Island RD0548 Terminous Tract RD2058 Pescadero RD0684 Lower Roberts Island San Joaquin RD2062 Stewart Tract RD0756 Bouldin Island RD2064 River Junction RD0773 Fabian Tract RD2075 McMullin Ranch RD0828 Weber Tract RD2085 Kasson RD1007 Pico-Naglee RD2089 Stark Tract RD1608 Smith Tract (Lincoln Village) RD2094 Wathall RD1614 Smith Tract

Annex B: Situation/Intelligence Annex B-46 Northern California Catastrophic Flood Response Plan

State Plan of Flood Control Non-State Plan of Flood Control County LMA LMA LMA Name LMA Name Number Number RD2095 Paradise Junction RD2023 Venice Island RD2096 Wetherbee Lake RD2027 Mandeville Island RD2107 Mossdale RD2028 Bacon Island San Joaquin County NA0017 Flood Control and Water RD2029 Empire Tract Conservation District RD2030 McDonald Island RD2033 Brack Tract RD2037 Rindge Tract RD2038 Lower Jones Tract RD2039 Upper Jones Tract RD2040 Victoria Island RD2041 Medford Island RD2042 Bishop Tract RD2044 King Island RD2072 Woodward Island RD2074 Sargent-Barnhart Tract RD2086 Canal Ranch RD2108 Tinsley Island RD2113 Fay Island RD2114 Rio Blanco Tract RD2115 Shima Tract RD2116 Holt Station RD2118 Little Mandeville Island RD2119 Wright-Elmwood Tract RD2126 Atlas Tract

RD2060 Hastings Collinsville Levee District RD2068 Yolano RD0501 Ryer Island RD2098 Cache and Haas Slough RD0536 Egbert Tract RD2104 Peters Pocket Tract RD0999 Netherlands Solano County Public NA0012 RD1607 Van Sickle Island Works Mellin Levee RD1667 Prospect Island Solano RD2034 Chadbourne RD2084 Little Egbert RD2093 Liberty Island RD2112 Schafer-Pintail RD2127 Simmons-Wheeler RD2129 Frost Lake RD2130 Honker Bay

Annex B: Situation/Intelligence Annex B-47 Northern California Catastrophic Flood Response Plan

State Plan of Flood Control Non-State Plan of Flood Control County LMA LMA LMA Name LMA Name Number Number RD2134 Denverton Slough RD2135 Sunrise Club RD2136 Grizzly West RD2138 Morrow Island RD2139 Can-Can/Greenhead

LD0009 Sutter County RD0777 RD 777 LD0015 Sutter County RD0817 Carlin RD0070 Meridian RD1000 Natomas RD1001 Nicolaus RD2054 Sutter RD1500 Sutter Basin RD2056 Kramer District RD1660 Tisdale RD2103 Wheatland Area DWR Sutter Maintenance NA0060 Yard (Structures and Sutter Channels) MA0003 Maintenance Area 3** MA0007 Maintenance Area 7** MA0016 Maintenance Area 16** ST0002 East Levee Sutter Bypass ST0006 Nelson Bend ST0009 Tisdale Bypass** ST0010 Wadsworth Canal ST0020 East-West Interceptor

RD0150 Merritt Island RD0730 Knights Landing RD0307 Lisbon RD2120 Little Holland Tract RD0537 Lovdal RD0765 Glide RD0785 Driver RD0787 Fair RD0827 Elkhorn RD0900 West Sacramento Yolo RD0999 Netherlands RD1600 Mull RD2035 Conaway Knights Landing Ridge NA0008 Drainage District Yolo County Planning NA0021 Resources and Public Works Yolo County Services NA0022 Area 6

Annex B: Situation/Intelligence Annex B-48 Northern California Catastrophic Flood Response Plan

State Plan of Flood Control Non-State Plan of Flood Control County LMA LMA LMA Name LMA Name Number Number MA0004 Maintenance Area 4*** ST0001 Cache Creek*** ST0004 East Levee Yolo Bypass ST0007 Putah Creek*** ST0008 Sacramento Bypass ST0011 West Levee Yolo Bypass ST0012 Willow Slough Bypass***

RD0784 Plumas Lake RD2103 Wheatland Area RD0817 Carlin Yuba Marysville Levee NA0004 Commission NA0006 Eastern Honcut Creek *Contra Costa does not have any levees in the State Plan of Flood Control Area ** Maintained by DWR’s Sutter Maintenance Yard *** Maintained by DWR’s Sacramento Maintenance Yard

LD – Levee District RD – Reclamation District NA – Named Area MA – Maintenance Area ST – State Maintenance Area

Annex B: Situation/Intelligence Annex B-49 Northern California Catastrophic Flood Response Plan

Appendix C: River Gage Data

Annex B: Situation/Intelligence Annex B-50 Northern California Catastrophic Flood Response Plan

Forecast Points in Planning Area

SACRAMENTO RIVER Top of Stages CNRFC Peak Stage and County Name Levee ID# Monitor Flood Danger Date of Record Elevation Butte/Glenn Hamilton City HAMC1 N/A 143.0’ 148.0’ N/A 150.92’ – 01/02/97 Butte/Glenn Ord Ferry ORFC1 N/A 110.0’ 114.0’ 122.6’ 120.10’ – 02/25/58 Glenn Butte City BTCC1 101.0’ 89.0’ 97.2’ 98.2’ 96.70’ – 02/20/58 Colusa Moulton Weir CLSC1 89.2’ 76.8’ 84.4’ 85.4’ 84.65’ – 02/20/58 Colusa Colusa Weir CLAC1 74.8’ 61.8’ 71.0’ 72.0’ 68.96’ – 03/04/83 Colusa Colusa Bridge CLUC1 73.0’ 63.0’ 70.0’ 71.0’ 68.50’ – 01/24/70 Sutter/ Tisdale Weir TISC1 57.0’ 45.5’ 53.0’ 54.0’ 53.10’ – 01/03/97 Colusa Sutter/Yolo Fremont Weir FMWC1 45.4’ 32.0’ 39.5’ 40.5’ 42.47’ – 01/02/97 Sutter/Yolo Verona VONC1 46.0’ N/A 41.3’ 42.3’ 42.11’ – 02/20/86 Sacramento/ Sacramento I Street SACC1 34.0’ 27.5’ 33.5’ 34.5’ 30.68’ – 02/19/86 Yolo Solano/ Rio Vista RVBC1 21.4’ 7.4’ 11.9’ 12.9’ 11.50’ – 02/20/86 Sacramento

AMERICAN RIVER Top of Stages CNRFC Peak Stage and County Name Levee ID# Monitor Flood Danger Date of Record Elevation Sacramento H Street SAMC1 47.5’ 39.0’ 42.0’ 43.0’ 43.40’ – 02/19/86

FEATHER RIVER Top of Stages CNRFC Peak Stage and County Name Levee ID# Monitor Flood Danger Date of Record Elevation Butte Gridley GRIC1 107.2’ 95.0’ 103.8’ 104.8’ 100.06’ – 02/19/86 Sutter/Yuba Yuba City YUBC1 83.5’ 65.0’ 80.2’ 81.2’ 78.23’ – 01/02/97 Sutter/Yuba Boyds Landing FBC1 70.0’ 57.0’ 65.0’ 66.0’ 59.24’ – 01/01/06 Sutter Nicolaus NCOC1 54.5’ 39.0’ 47.0’ 48.0’ 50.40’ – 01/02/97

YUBA RIVER Top of Stages CNRFC Peak Stage and County Name Levee ID# Monitor Flood Danger Date of Record Elevation Yuba Marysville MRYC1 93.0’ 74.0’ 87.0’ 88.0’ 92.15’ – 12/22/64

Annex B: Situation/Intelligence Annex B-51 Northern California Catastrophic Flood Response Plan

CACHE CREEK Top of Stages CNRFC Peak Stage and County Name Levee ID# Monitor Flood Danger Date of Record Elevation Yolo Yolo YLOC1 84.1’ 75.0’ 81.0’ 82.1’ 85.35’ – 02/25/58

SAN JOAQUIN RIVER Top of Stages CNRFC Peak Stage and County Name Levee ID# Monitor Flood Danger Date of Record Elevation San Joaquin Vernalis VNSC1 37.3’ 24.5’ 29.0’ 29.5 34.88’ – 01/05/97 San Joaquin Mossdale MOSC1 33.1’ 19.5’ 28.5’ 29.5’ 24.40’ – 12/10/50 San Joaquin Mormon Slough - MSGC1 ?? 16.0 22.0 23.0 ??? (NEW) Bellota

COSUMNES RIVER Top of Stages CNRFC Peak Stage and County Name Levee ID# Monitor Flood Danger Date of Record Elevation Sacramento Michigan Bar MHBC1 13.2’ 7.0’ 12.0’ N/A 18.54’ – 01/02/97 Sacramento McConnell MCNC1 N/A 40.0’ 46.0’ N/A 48.50’ – 01/02/97

MOKELUMNE RIVER Top of Stages CNRFC Peak Stage and County Name Levee ID# Monitor Flood Danger Date of Record Elevation Sacramento Benson’s Ferry THTC1 N/A 12.0’ 17.0’ N/A 21.69’ – 01/02/97

YOLO BYPASS Top of Stages CNRFC Peak Stage and County Name Levee ID# Monitor Flood Danger Date of Record Elevation Yolo Libson LSBC1 31.1’ 13.0’ 19.0’ 26.2’ 27.50’ – 02/20/86

For more information on gages and flooding impacts, go to: http://www.cnrfc.noaa.gov/

*Highlighted data is from new elevation datum reference update to North American Vertical Datum of 1988 (NAVD88)

Annex B: Situation/Intelligence Annex B-52 Northern California Catastrophic Flood Response Plan

Forecast Points Outside of Planning Area That Could Impact Planning Area

SACRAMENTO RIVER (Impact Butte & Glenn County) Top of Stages CNRFC Peak Stage and County Name Levee ID# Monitor Flood Danger Date of Record Elevation Tehama Bend Bridge BDBC1 N/A 22.0’ 27.0’ N/A 36.60’ – 01/24/70 Tehama Red Bluff RDBC1 N/A 250.0’ 253.0’ N/A 260.00’ – 01/01/97 Tehama Tehama Bridge TEHC1 N/A 210.0’ 213.0’ N/A 222.70’ – 03/01/83 Tehama Vina Woodson Bridge VWBC1 N/A 180.0’ 183.0’ N/A 191.50’ – 01/24/70

MIDDLE FORK FEATHER RIVER (Impact Butte County) Top of Stages CNRFC Peak Stage and County Name Levee ID# Monitor Flood Danger Date of Record Elevation Plumas Portola MFTC1 N/A 7.0’ 8.5’ N/A 10.62’ – 01/21/69

MERCED RIVER (Impact San Joaquin County) Top of Stages CNRFC Peak Stage and County Name Levee ID# Monitor Flood Danger Date of Record Elevation Mariposa Pohono Bridge POHC1 N/A N/A 10.0’ N/A 23.43’ – 01/03/97 Merced Stevinson STVC1 N/A 67.0’ 71.0’ N/A 73.81’ – 12/05/50

BEAR RIVER (Impact Yuba & Sutter County) Top of Stages CNRFC Peak Stage and County Name Levee ID# Monitor Flood Danger Date of Record Elevation Placer Wheatland BRWC1 33.1’ 16.0’ 24.0’ 25.0’ 24.28’ – 12/31/05

SAN JOAQUIN RIVER (Impact San Joaquin County) Top of Stages CNRFC Peak Stage and County Name Levee ID# Monitor Flood Danger Date of Record Elevation Merced Newman NWMC1 71.7’ 63.0’ 69.4’ 70.4’ 66.26’ – 04/09/06 Stanislaus Patterson PATC1 58.3’ 48.0’ 54.7’ 55.7’ 51.26’ – 03/04/83

Annex B: Situation/Intelligence Annex B-53 Northern California Catastrophic Flood Response Plan

BEAR CREEK (Impact San Joaquin County) Top of Stages CNRFC Peak Stage and County Name Levee ID# Monitor Flood Danger Date of Record Elevation Merced McKee Road MEEC1 N/A 17.0’ 23.0’ N/A 24.65’ – 04/04/06

STANISLAUS RIVER (Impact San Joaquin County) Top of Stages CNRFC Peak Stage and County Name Levee ID# Monitor Flood Danger Date of Record Elevation Stanislaus Orange Blossom OBBC1’ N/A 13.0’ 16.0’ N/A 13.95’ – 01/02/97

TUOLUMNE RIVER (Impact San Joaquin County) Top of Stages CNRFC Peak Stage and County Name Levee ID# Monitor Flood Danger Date of Record Elevation Stanislaus Modesto MDSC1 N/A 50.5’ 55.0’ N/A 71.21’ – 01/04/97

For more information on gages and flooding impacts, go to: http://www.cnrfc.noaa.gov/

Annex B: Situation/Intelligence Annex B-54 Northern California Catastrophic Flood Response Plan

Figure B-17: Sacramento River Flood Control System & Official Forecast Points

Annex B: Situation/Intelligence Annex B-55 Northern California Catastrophic Flood Response Plan

Moulton Weir Built 1932

Colusa Weir Built in 1932

Annex B: Situation/Intelligence Annex B-56 Northern California Catastrophic Flood Response Plan

Tisdale Weir Built 1932

Fremont Weir Built 1924

Annex B: Situation/Intelligence Annex B-57 Northern California Catastrophic Flood Response Plan

Sacramento Weir Built in 1916

Annex B: Situation/Intelligence Annex B-58