Agenda packet — Portola City Council, June 10, 2026 (part 9 of 14)

Plumas County IVCSD Annex E-41
Local Hazard Mitigation Plan Update
January 2026
Table E-9 IVCSD – List of Localized Flooding Problem Areas Road/Area
Name Flooding
Pavement
Deterioration Washouts
High
Water/
Creek
Crossing
Landslides/
Mudslides Debris
Downed
Trees
All of Greenville
if the dam breaks
or there are
extreme storms
w/flash floods

X X X X X X X
Source: IVCSD
The District has concerns related to more extreme weather such as atmospheric rivers followed by severe drought increasing flash flood risk. Vulnerabilities stem from increased severe weather, the Feather River overflowing, mountainous terrain, and specific aftereffects of the Dixie Fire. Localized flood events can and do result in loss of service, which impacts the residents within the District’s boundaries.

Assets at Risk
Assets at risk from this hazard include people and populations; structures and critical facilities; and natural, historic, and cultural resources. These are discussed in the following sections.

People and Populations
All District staff and populations served (including vulnerable populations) are traditionally not highly vulnerable to localized flooding, but their structures and contents can be at risk. Localized flooding may also cause transportation issues as roads and lanes are impacted or closed and affect the ability for District staff and District residents to travel throughout the District.

Structures and Critical Facilities and Infrastructure
Structures and critical facilities and infrastructure in areas with localized flooding can be affected if floodwaters intrude into the structure. Structures in low lying areas, can be at greater risk. Buildings with older foundations that are prone to water intrusion are also at greater risk. Once water finds its way into a structure, it tends to continue to do so until the path that brings water into a structure is mitigated. Structures can also be damaged by trees that have become uprooted and fall during rain and storm events. Large trees falling onto structures can cause significant damage.

Many of the assets listed as being affected by flood in Table E-2 can also be affected by localized floods.

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increasing fish production, creating wildlife habitat, and rejuvenating soil fertility. These smaller localized flooding events often provide more benefits to the environment in comparison to negative impacts associated with large flood events. Historic and cultural resources may be at some measure of vulnerability if they are located in areas subject to repeated localized flooding.

Impacts from Localized Flood
Primary concerns associated with stormwater flooding include impacts to infrastructure that provide a means of ingress and egress throughout the community. Ground saturation can result in instability, collapse, or other damage to trees, structures, roadways and other critical District infrastructure. Objects can also be buried or destroyed through sediment deposition. Floodwaters can break utility lines and interrupt services to District facilities. Standing water can cause damage to crops, roads, and foundations of District facilities. Other problems connected with flooding and stormwater runoff include erosion, sedimentation, degradation of water quality, losses of environmental resources, and certain health hazards.

Life safety issues from localized flooding would be more limited. The amount and type of damage or flooding that occurs varies from year to year and from storm to storm, depending on the quantity of precipitation and runoff.

Impacts to identified assets at risk to this hazard and the overall vulnerability of the District may be affected in the future by climate change (which was discussed in the Likelihood of Future Occurrence discussion above), changes in population patterns (migration, density, or the makeup of socially vulnerable populations), and changes in land use and development. These are discussed below.

Future Conditions/Future Development
This section provides a discussion of how future conditions will influence or affect the hazard over time and also discusses future development relative to each hazard.

Future Conditions
Future conditions may be affected by climate change, changes in population patterns (migration, density, or the makeup of socially vulnerable populations), and changes in land use and development. Findings on this for the IVCSD include the following:
➢ As discussed in the hazard profile section, climate change is anticipated to exacerbate this hazard over time.
➢ Population projections within the District’s service area show the population to be slightly declining. It is unknown how population patterns and demographics will change in the near future. The District may add staff, but this number would be relatively small. The District noted that it has no control over population changes within its service area. With no notable changes in populations numbers and makeup, the vulnerability of the District to a dam failure is unlikely to change. ➢ Changes in land use and development within the District’s service area are expected to be limited in the near future and thus are not likely to affect dam failure impacts to the District. The District is currently rebuilding its Greenville Fire Station. No other development is currently being planned by the District. New development continues in the District’s service area with recovery efforts ongoing in the

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aftermath of the Dixie Fire. The District noted that it has no control over land use and development within its service area. With limited future growth and development occurring, the vulnerability of the District to this hazard is unlikely to change.

Future Development
Land use planning should be proactive to address future hazard conditions. The District is currently rebuilding the Greenville fire station that was destroyed in the 2021 Dixie Fire. This is the only new development currently planned by the District. With respect to future development within its service area, new development and rebuilds continue with recovery efforts ongoing in the aftermath of the Dixie Fire.

The risk of stormwater/localized flooding to future development can be minimized by accurate recordkeeping of repetitive localized storm activity. Mitigating the root causes of the localized stormwater or choosing not to develop in areas that often are subject to localized flooding will reduce future risks of losses due to stormwater/localized flooding. Future development in the District will add to the drainage issues already faced by the District, unless adequate drainage facilities are installed in new development locations.

Landslide, Mudslide, and Debris Flow
Likelihood of Future Occurrence–Likely
Vulnerability–Medium
Hazard Profile
Like its earthquake‐generating faults, California’s mountainous terrain is a consequence of dynamic geologic processes in operation as the North American Plate grinds past the Pacific Plate. According to the CGS, a landslide is a general term for a variety of mass-movement processes that generate a down-slope movement of mud, soil, rock, and/or vegetation. Landslides are classified into many different types based on form and type of movement. They range from slow‐moving rotational slumps and earth flows, which can slowly distress structures but are less threatening to personal safety, to fast‐moving rock avalanches and debris flows that are a serious threat to structures and have been responsible for most fatalities during landslide events. For the purposes of this LHMP Update, the term landslide includes mudslides, debris flows, and rockfalls that tend to occur suddenly; as well as hillside erosion, which is a similar process that tends to occur on smaller scales and more gradually but can exacerbate landslide events.

Landslides, debris flows and mudslides are closely related to flooding, as both processes are related to precipitation, runoff, and the saturation of ground by water. In addition, landslides, mud flows, and debris flows can occur on small, steep stream channels and are often mistaken for floods. However, landslide events may be much more destructive than floods because of their higher densities, high debris loads, and high velocities.

Natural conditions that contribute to landslide, mudslides, debris flows, hillside and streambank erosion, include the following:
➢ Degree of slope
➢ Water (heavy rain, river flows, or wave action)

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➢ Unconsolidated soil or soft rock and sediments
➢ Lack of vegetation (no stabilizing root structure)
➢ Previous wildfires and other forest disturbances (discussed in the Wildfire section below) ➢ Road building, excavation, and grading
➢ Earthquake
The 2023 California State Hazard Mitigation Plan noted that more than one third of California is mountainous terrain that generally trends parallel to the coast, forming a barrier that captures moisture from offshore storms originating in the Gulf of Alaska and Mexico. Steep topography, weak rocks, heavy winter rains, and occasional earthquakes all lead to slope failures more frequently than would otherwise occur under gravity alone. This is true in the sloped areas bordering the District where the topography is characterized by rolling hills and ridges.

Location and Extent
Landslides can occur in areas with steep slopes and weak soils. It can also occur in areas where erosion has previously occurred. Both winter storms (precipitation-induced) and earthquake triggered landslides tend to occur in or near places that have experienced previous landslides. However, landslides may also occur in other locations over time. Landslides and debris flows may also occur in fire burn scar areas.

Figure E-6 shows the CGS areas at susceptible to deep-seated landslides. The legend on Figure E-6 shows the susceptibility scale (from 0-X with 0 being the least and X being the most susceptible) that the CGS uses to show the susceptibility of landslides. It is a primarily a combination of slope class and rock strength.

Geographic extents of these classes are shown on Table E-10. According to the 2023 State Hazard Mitigation Plan, the susceptibility classes were further categorized into Very High (susceptibility class X) and High (susceptibility classes VII, VIII, & IX) for exposure analysis. The rest of the classes were not categorized. CGS mapping indicates that the eastern portions of the District and surrounding area are at high to very high susceptibility areas for landslides. This can be seen in the darker orange and red colors.

The speed of onset of landslide is often short, especially in past landslide areas as well as in post-wildfire burn scar areas, but it can also take years for a slope to fail. Landslide duration is usually short, though digging out and repairing landslide areas can take some time.

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Figure E-6 IVCSD – Susceptibility to Deep-Seated Landslides Table E-10 IVCSD – Susceptibility to Deep-Seated Landslide Geographical Extents by Class Susceptibility
to Deep-Seated
Landslide Class
Total Acres % of Total
Acres
Improved
Acres
% of Total
Improved
Acres
Unimproved
Acres
% of Total
Unimproved
Acres
Fire District
0 1,581 9% 370 7% 1,211 10%
III 161 1% 55 1% 105.9 1%
V - 0% - 0% - 0%
VI 199 1% 50 1% 149 1%
VII 677 4% 260 5% 416 3%
VIII 70 0.4% 5 0.1% 64 1%
IX 141 1% 36 1% 105 1%
X 130 1% 42 1% 88 1%
Total 2,958 17% 819 15% 2,139 18%

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Susceptibility
to Deep-Seated
Landslide Class
Total Acres % of Total
Acres
Improved
Acres
% of Total
Improved
Acres
Unimproved
Acres
% of Total
Unimproved
Acres
Water/Wastewater District
0 6,505 37% 2,440 44% 4,064 34%
III 796 5% 176 3% 620 5%
V 60 0.3% 37 1% 23 0.2%
VI 962 5% 194 4% 768 6%
VII 4,257 24% 1,320 24% 2,937 24%
VIII 628 4% 81 1% 546 5%
IX 671 4% 214 4% 457 4%
X 686 4% 208 4% 478 4%
Total 14,564 83% 4,671 85% 9,893 82%
Grand Total 17,522 100% 5,490 100% 12,032 100%
Source: CGS
Past Occurrences
Disaster Declarations
There have been no disaster declarations associated with just landslides in Plumas County; however, as shown in Table E-11, there have been 9 state and 10 federal disaster declarations for flood (including heavy rains and storms) which included landslides as a component.

Table E-11 Plumas County – Federal and State Disaster Declarations Summary 1950-2025 Disaster Type State Declarations Federal Declarations
Count Years Count Years
Flood (events that
included landslide)
9 1995 (twice), 2006 (twice), 2017
(twice), 2019, 2023 (twice)
10 1995 (twice), 2006 (twice), 2017
(twice), 2019, 2023 (three)
Source: Cal OES, FEMA. Retrieved March 2025.

NCDC Events
The NCDC contains 21 records for landslides or debris flows in Plumas County since 1993.

IVCSD Past Occurrences
The District experienced localized landslides, mudslides, and debris flow in early 2023. The area was especially susceptible to these events due to the Dixie Fire in 2021. Rain could not be absorbed into the ground and ran off quickly, overwhelming drainage systems. There were no roots from vegetation to hold the soil in place because of the devastation caused by the Dixie Fire. The debris flow and mudslides led to the closure of local highways (specifically, Highway 70 & 89). The area was still trying to rebuild from the Dixie Fire. The mudslides and flooding added another layer of challenges for the community. To

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mitigate these hazards, the District worked to establish drainage control, clear and maintain existing drainage, use sandbags and silt fences to create temporary barriers & redirect water, spread erosion control blankets and hydromulch on steep hillsides, install erosion barriers, create check dams from straw bales to slow and control runoff as much as possible. There were several road closures, and significant strain on local services such as maintenance crews and emergency services.

There was also significant debris flow in October of 2021 due to storms. Roads were washed out, bridges were damaged, and culverts were damaged. Property damage was minimal. Transportation routes were primarily affected. Greenville was cut off from supplies, residents' ability to commute to work was impacted which impacted the local businesses and economy. Costs increased due to increased travel time.

There was also environmental and geological damage due to the combination of the Dixie Fire and intense rainfall triggered erosion.

A grant application noted that during DR-4308 incident period of February 1, 2017 through February 23, 2017, IVSCD experienced severe winter storms, flooding which caused damage to Greenville Water Treatment Road. Heavy rains and high water flooding brought rock, silt, plants, and vegetative debris down the hillside which overwhelmed and damaged the drainage canal directly next to the road. The remaining debris and flood waters overwhelmed, clogged and damaged the upper division culvert completely washing out a section of the road. The culvert was damaged beyond repair.

Climate Change and Landslide and Debris Flows
According to the 2021 CAS (as well as the 2024 Draft CAS), climate change may result in precipitation extremes (i.e., wetter wet periods and drier dry periods). More information on precipitation increases can be found in Section 4.3.4 of the Base Plan. While total average annual rainfall may decrease only slightly, rainfall is predicted to occur in fewer, more intense precipitation events. The combination of a generally drier climate in the future, which will increase the chance of drought and wildfires, and the occasional extreme downpour is likely to cause more mudslides, landslides, and debris flows.

Vulnerability from Landslide
Portions of the District are at some measure of vulnerability to landslide. This is true when atmospheric rivers or heavy rain and storm events occur. Post wildfire areas are also more prone to landslide events.

An assessment of a community’s vulnerability to landslide begins with an understanding of local exposure to landslide. This is included in the Local Concerns section below followed by a discussion of the District’s Assets at Risk to this hazard.

The District is concerned both with physical damage to District property, as well as damage to transportation routes in the area. In addition, as the residents of the District have seen damages from the Dixie Fire, there is concern for landslides in fire burn scar areas.

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After a fire has occurred, destabilized soil and erosion can occur within the burn scar, exacerbating the risks of landslide. A concern of the District is the fact that the risk of debris flow is not just immediately following wildfire, it can persist for years because of slow vegetation regrowth and continuous decay of soil. Along with those cascading effects, other events such as extreme weather & atmospheric rivers, rapid and destructive flows, threat to infrastructure and life, and water contamination are all impacts that the District is concerned about. Lack of early warning systems, financial burden, and ongoing road closures are impacts that the residents would be facing within the District. It can be challenging to discourage these residents from returning to an area affected by landslide, which can cause more issues, especially for emergency response services.

People and Populations
All populations (both District staff and District residents) located within areas of landslide susceptibility, especially in the High to Very High hazard areas (i.e., Classes VII to X) are at some vulnerability to landslide. Most vulnerable are those people working or residing in these landslide potential areas as well as those that might reside or work within the landslide run out areas. People residing in the District service areas as well as District staff may also be cut off from transportation routes if roads and streets providing a means of ingress and egress are impacted. Certain vulnerable populations may be at greater risk due to the often sudden onset of a landslide event and include: the unsheltered, those with limited mobility, and those that lack the resources to leave the area.

Structures and Critical Facilities and Infrastructure
Landslides can affect the built environment of the District and those structures and critical facilities located within the High to Very High hazard areas (i.e., Classes VII to X) are especially vulnerable, as are the structures located within the landslide run out areas. The District noted that it is concerned that all assets listed in Table E-2 would have some risk to landslide.

Natural, Historic, and Cultural Resources
Landslides can affect natural, historic, and cultural resources that lie in the landslide area, or the landslide run out area. Landslides can destroy large tracts of forest and open space areas, destroy wildlife habitat, and remove productive soils and vegetation from slopes. It can also fill in waterways, impact water quality, and potentially affect flooding potential. Natural resources that fall in the High or Very High susceptibility areas shown on Figure E-6 would be most vulnerable, as well as those in the run-out areas.

Impacts from Landslide
Any type of landslide may result in damages or complete destruction of buildings in their path, as well as deaths and injuries. Landslides can cause road blockages by depositing debris on road surfaces or road damage if the road surface itself slides downhill. Utility lines and pipes are also prone to breakage in slide

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areas. Large landslides can collapse into water bodies, causing seiches. Landslides can relocate river channels. Landslides and debris flows can also impact water quality and the storage capacity of surface water reservoirs used to store potable water.

Landslides, debris flows, and mud flows impacts vary by location and severity of any given event and will likely only affect certain areas of the District susceptible to landslide. Based on the risk assessment, there is limited potential for significant landslides to occur in the District. Most, but not all, of the historic landslides in the District have been minor, localized events that are more of a nuisance than a disaster.

However, with the Dixie Fire burn scar, this may change in the future. Impacts that are not quantified, but can be anticipated in large future events, include:
➢ Injury and loss of life;
➢ Disruption of and damage to public infrastructure, utilities, and services; ➢ Damage to roads/bridges resulting in loss of mobility; and ➢ Significant economic impact (jobs, sales, tax revenue) to the community.

Impacts to identified assets at risk to this hazard and the overall vulnerability of the District may be affected in the future by climate change (which was discussed in the hazard profile above), changes in population patterns (migration, density, or the makeup of socially vulnerable populations), and changes in land use and development. These are discussed in the Future Conditions/Future Development discussion below.

Future Conditions
Future conditions may be affected by climate change, changes in population patterns (migration, density, or the makeup of socially vulnerable populations), and changes in land use and development. Findings on this for the District include the following:
➢ Climate change is likely to exacerbate future landslide, mudslide, and debris flow conditions and associated impacts and vulnerability of the District to landslide. ➢ Population projections within the District’s service area show the population to be slightly declining. It is unknown how population patterns and demographics will change in the near future. The District may add staff, but this number would be relatively small. The District noted that it has no control over population changes within its service area. With no notable changes in populations numbers and makeup, the vulnerability of the District to a dam failure is unlikely to change. ➢ Changes in land use and development within the District’s service area are expected to be limited in the near future and thus are not likely to affect dam failure impacts to the District. The District is currently rebuilding its Greenville Fire Station. No other development is currently being planned by the District. New development continues in the District’s service area with recovery efforts ongoing in the aftermath of the Dixie Fire. The District noted that it has no control over land use and development within its service area. With limited future growth and development occurring, the vulnerability of the District to this hazard is unlikely to change.

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Future Development
Land use planning should be proactive to address future hazard conditions. The District is currently rebuilding the Greenville fire station that was destroyed in the 2021 Dixie Fire. This is the only new development currently planned by the District. With respect to future development within its service area, new development and rebuilds continue with recovery efforts ongoing in the aftermath of the Dixie Fire.

Additional growth and development within moderate or higher deep-seated landslide susceptibility classes (Class VI I– Class X) in the District would place additional values at risk to landslide. New District facilities should take landslide into account when siting new facilities.

Severe Weather: Heavy Rains and Storms
Likelihood of Future Occurrence–Highly Likely
Vulnerability–Medium
Hazard Profile
Storms in the District occur annually and are generally characterized by heavy rain often accompanied by strong winds and sometimes lightning and hail. Approximately 10 percent of the thunderstorms that occur each year in the United States are classified as severe. A thunderstorm is classified as severe when it contains one or more of the following phenomena: hail that is three-quarters of an inch or greater, winds in excess of 50 knots (57.5 mph), or a tornado. Heavy precipitation in the District falls mainly in the fall, winter, and spring months. It can come normally, or as part of an atmospheric river event. Those events were discussed in Section 4.3.4 of the Base Plan. Wind often accompanies these storms; hail and lightning are rare in the District. Rain coming during times of snow are of particular concern to the District, as even smaller rains can melt snow, causing flooding issues.

Location and Extent
Rains and storms can occur in any location of the District. According to the Plumas County Average Annual Precipitation Map shown in Section 4.3.4 of the Base Plan, the District sees 39" to 47" of precipitation each year. All portions of the District are at risk to heavy rains and storms. Most of the severe rains occur during the fall, winter, and spring months in the District as discussed below (with problem flooding areas associated with heavy rains and storms shown in Table E-9 in the Flood: Localized Stormwater section). There is no scale by which heavy rains and severe storms are measured. Magnitude of storms is measured often in rainfall and damages. The speed of onset of heavy rains can be short, but accurate weather prediction mechanisms often let the public know of upcoming events. Hail and lightning are rarer in the District and Plumas County. Duration of severe storms in the District can range from minutes to hours to days.

Past Occurrences
Disaster Declaration History
According to historical hazard data, severe weather, including heavy rains and storms, is an annual occurrence in the District. This contributes to many of the federal disaster declarations related to flooding.

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Disaster declarations from flooding, including heavy rains and storms, are shown on Table E-12. In addition, there have been two USDA disaster declarations from heavy rain and storms (once in 2016 and once in 2017) since 2012.

Table E-12 Plumas County – State and Federal Disaster Declarations from Flood (Heavy Rain and Storms) 1950-2025
Disaster Type State Declarations Federal Declarations
Count Years Count Years
Flood (including heavy
rains and storms)
22 1950, 1955, 1958 (twice), 1964,
1963, 1964, 1969, 1970 1980,
1986, 1993, 1992*, 1995
(twice*), 1996, 1997, 2006, 2017
(twice*), 2023 (twice*)
19 1950, 1955, 1958 (twice), 1963,
1964, 1969, 1970, 1986, 1992
(twice), 1995 (twice), 1997,
2006*, 2017 (twice*), 2023
(twice*)
Source: Cal OES, FEMA
NCDC Events
The NCDC data recorded 132 hail, heavy rain, and storm incidents for Plumas County since 1950.

IVCSD Events
The District noted that heavy rains and storms are an annual occurrence often resulting in flooding. Events causing flood issues are listed in the Past Occurrences section of the Flood: 1%/0.2% Annual Chance and Flood: Localized Stormwater Flooding discussions above.

Climate Change and Heavy Rains and Storms
It is likely that climate change will increase the chance of future occurrence as well as future impacts from heavy rains and storms. More information on future impacts to the District can be found in the Future Conditions/Future Development section of the Vulnerability Assessment below.

According to the 2021 CAS (as well as the 2024 Draft CAS), while average annual rainfall may increase or decrease slightly, the intensity of individual rainfall events is likely to increase during the 21st century.

It is unlikely that hail will become more common in Plumas County and the IVCSD. The amount of lightning is not projected to change.

Cal-Adapt noted that, on average, the projections show little change in total annual precipitation in California. Furthermore, among several models, precipitation projections do not show a consistent trend during the next century. Cal-Adapt modeled scenarios are shown in Section 4.3.4 of the Base Plan.

Vulnerability to Heavy Rain and Storms
Heavy rain and severe storms are the most frequent type of severe weather occurrences in the District.

These events can cause both significant and localized flooding. Flooding can be worse during times where the ground is already saturated. Wind often accompanies these storms and has caused damage in the past.

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Hail and lightning are rare in the District, but also can cause damage, with lightning occasionally igniting wildfires.

The whole of the District is at some measure of vulnerability to heavy rain and storms. An assessment of a community’s vulnerability to heavy rains and storms begins with an understanding of local exposure to heavy rain and storms. This is included in the Local Concerns section below followed by a discussion of the District’s Assets at Risk to this hazard.

The District noted that one of the primary issues associated with heavy rains and storms is the resulting flooding caused by large precipitation events. A list of localized flooding problem areas are shown on Table E-9 above. The District is also concerned with rain on snow events, which can cause greater flooding in the District. The District is also concerned about increased debris flow and mudslide risk, localized flooding, water contamination, erosion, and landscape damage. Concerns for PSPS events include medical needs for residents that rely on electricity for medical devices and refrigerated medication, communication breakdowns, disruption of recovery, food and water security, and mental health impact.

Also of concern to the District are cascading events, such as flash floods and debris flow, with increased risk on steep terrain downstream due to the Dixie Fire burn scar, and water contamination. These events can all cause increased infrastructure damage, service disruptions, increased costs, safety risks, isolation, access problems, rebuilding delays, and financial strain.

People and Populations
All District staff and the populations served by the District are at some vulnerability to heavy rains and storms. Those District employees that work outdoors could be affected to a limited extent by this hazard.

All populations served by the District have some measure of risk to heavy rains and storms. Those populations that work or recreate outside and unhoused individuals are more vulnerable to impacts from heavy storm events. Heavy rains and storms occur every year and do not generally cause significant adverse impacts to individuals; it is the secondary hazard, flooding and the potential for landslides and debris flows, which poses the biggest impact to people.

Structures and Critical Facilities and Infrastructure
District facilities and structures have some risk to heavy rains and storms. Heavy rain and storms can affect critical facilities and infrastructure during large events. Structures built to modern building codes are built

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to withstand heavy rains and storms (including thunderstorm winds and lightning); older structures may be more vulnerable. During a heavy storm, localized flooding may cause water intrusion into buildings from the outside. Trees can be downed causing impacts to structures. Older homes and buildings may be at increased risk to heavy rains and storms. Power outages during severe storm events can occur, impacting the use of structures until the power is back online. Local roads, streets, and bridges can be impacted resulting in closures restricting traffic flow in the District. In certain areas, large storms can cause erosion and localized landslides which can impact affected facilities.

Heavy rains and storms that cause flooding and landslide events pose a risk to all District assets listed in Table E-2.

Natural, Historic, and Cultural Resources
Large rain and storm events and associated flooding can affect natural, historic, and cultural resources. Silt and sediment can damage natural areas. Trees can be uprooted and downed by high winds. Extended periods of rainfall can erode natural banks along waterways and degrade soil stability for terrestrial species.

While some natural systems can be adversely impacted during these large storms, heavy rain events can also provide benefits. Groundwater and wetland areas can be recharged and water supplies replenished.

Historic and cultural resources may also be affected. Generally, the impacts are associated with damage to structures affected by large storm events, but other cultural resources such as those associated with Native Americans and old tribal areas can also be disturbed, damaged, and lost during extreme rain and storm and events.

Impacts from Heavy Rain and Storms
Impacts from heavy rains and storms include damage to property, critical facilities and infrastructure, and the natural landscape. This includes: erosion; downed trees; damaged utility structures and infrastructure; power outages; road damage and blockages; and even lightning strikes to critical infrastructure and people.

Lightning can also cause wildfires and urban fires to occur. Landsliding and erosion occur when the soil on slopes becomes oversaturated and fails. Climate change may cause these impacts to worsen.

Actual damage associated with the primary effects of severe storms and heavy rains has been somewhat limited. It is the secondary hazards caused by these severe weather events, such as floods and erosion that would likely have the greatest impact.

Impacts to identified assets at risk to this hazard and the overall vulnerability of the District may be affected in the future by climate change (which was discussed in the hazard profile section above), changes in population patterns, and changes in land use and development. The influencing effects of these factors on this hazard are discussed further in the Future Conditions/Future Development discussion below.

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Future Conditions
Future conditions may be affected by climate change, changes in population patterns (migration, density, or the makeup of socially vulnerable populations), and changes in land use and development. Findings on this for the District include the following:
➢ As discussed in the hazard profile section, climate change is anticipated to exacerbate this hazard over time.
➢ Population projections within the District’s service area show the population to be slightly declining. It is unknown how population patterns and demographics will change in the near future. The District may add staff, but this number would be relatively small. The District noted that it has no control over population changes within its service area. With no notable changes in populations numbers and makeup, the vulnerability of the District to a dam failure is unlikely to change. ➢ Changes in land use and development within the District’s service area are expected to be limited in the near future and thus are not likely to affect dam failure impacts to the District. The District is currently rebuilding its Greenville Fire Station. No other development is currently being planned by the District. New development continues in the District’s service area with recovery efforts ongoing in the aftermath of the Dixie Fire. The District noted that it has no control over land use and development within its service area. With limited future growth and development occurring, the vulnerability of the District to this hazard is unlikely to change.

New District facilities follow state and local building codes which should reduce the risk to future development in the District from heavy rains and storms and secondary hazards. New critical facilities should be built to withstand hail damage, lightning, and thunderstorm winds. Changes in land use may also amplify the impacts of heavy rains and storms, as additional impervious surfaces can cause additional runoff and localized flooding throughout the District.

Wildland fires affect grass, forest, and brushlands, as well as structures. Where there is human access to wildland areas, the risk of fire increases due to a greater chance for human carelessness and historical fire management practices. Historically, the fire season extends from early spring through late fall of each year

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during the hotter, dryer months; however, in recent years, the risk of wildfire has become a year around concern.

Fire conditions arise from a combination of high temperatures, low moisture content in the air and fuel, accumulation of vegetation, and high winds. These weather conditions can result in red flag (e.g., fire weather) days, and can result in PSPS events in the District. While wildfire risk has predominantly been associated with more remote forested areas and wildland urban interface (WUI) areas, significant wildfires also occur in more populated developed areas. There is also the concern of wildfires occurring in these more remote, forested areas, that under certain weather conditions, can extend into areas not generally considered at a high risk to wildfire. Smoke and air quality also become an issue, both from fires occurring inside and outside of the Plumas County Planning Area and the District.

Wildfire Smoke and Air Quality
Smoke from wildfires is made up of gas and particulate matter, which can be easily observed in the air. Air quality standards have been established to protect human health with the pollutant referred to as PM2.5 which consists of particles 2.5 microns or less in diameter. These smaller sizes of particles are responsible for adverse health effects because of their ability to reach the lower regions of the respiratory tract.

Wildfire smoke can have negative effects to those who live in or near a fire burn area. Smoke and air pollution from wildfires can be a severe health hazard. Significant wildfires occurring in both Plumas County, nearby northern California communities, and elsewhere have created significant air pollution affecting area residents. This was the case during the 2021 Caldor Fire, as well as others that affected the Plumas County Planning Area.

Location and Extent
Wildfire can affect all areas of the District. CAL FIRE has estimated that the risk varies across the District and has created maps showing risk variance. Following the methodology described in Section 4.3.16 of the Base Plan, wildfire maps for the IVCSD were created. Figure E-7 shows the CAL FIRE State Responsibility Areas (SRA) and Federal Responsibility Areas (FRA) and their associated Fire Hazard Severity Zones (FHSZ) in the District. As shown on the map, FHSZs within the District range from Moderate to Very High. Figure E-8 shows the CAL FIRE Local Responsibility Areas (LRA) and their associated Fire Hazard Severity Zones (FHSZ) in the District. As shown, there is no LRA in the District; as such, no other tabular analysis of the LRA is provided in the sections below.

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January 2026
Figure E-7 IVCSD – CAL FIRE SRA/FRA Fire Hazard Severity Zones

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Figure E-8 IVCSD – CAL FIRE LRA Fire Hazard Severity Zones Wildfires tend to be measured in structure damages, injuries, and loss of life as well as on acres burned.

Fires can have a quick speed of onset, especially during periods of drought or during hot dry summer months. Fires can burn for a short period of time or may have durations lasting for a week or more.

Geographical FHSZ extents in the SRA/FRA for both the Fire District and the Water/Wastewater District are shown in Table E-13.

Table E-13 IVCSD – CAL FIRE SRA/FRA Fire Hazard Severity Zone Geographical Extents Fire Hazard
Severity Zones
Total Acres % of Total
Acres
Improved
Acres
% of Total
Improved
Acres
Unimproved
Acres
% of Total
Unimproved
Acres
Fire District
Very High 1,418 8% 431 8% 987 8.2%
High 1,526 9% 387.7549 7% 1,138 9.5%
NonWildland/NonUrban14 0.1% 0 0% 14 0.1%

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Local Hazard Mitigation Plan Update
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Fire Hazard
Severity Zones
Total Acres % of Total
Acres
Improved
Acres
% of Total
Improved
Acres
Unimproved
Acres
% of Total
Unimproved
Acres
Fire District Total 2,958 17% 819 15% 2,139 17.8%
Water/Wastewater District
Very High 10,727 61% 3,324 61% 7,403 61.5%
High 3,715 21% 1,321 24% 2,395 19.9%
Moderate 114 1% 26 0.5% 89 0.7%
NonWildland/NonUrban7 0.04% 0 0% 7 0.1%
Water/Wastewater
District Total
14,564 83% 4,671 85% 9,893 82.2%
Grand Total 17,522 100% 5,490 100% 12,032 100%
Source: CAL FIRE
Past Occurrences
Disaster Declaration History
There has been eight state and six federal disaster declarations due to fire, as shown in Table E-14.

Table E-14 Plumas County – State and Federal Wildfire Disaster Declarations 1950-2025 Disaster Type State Declarations Federal Declarations
Count Years Count Years
Fire 8 1960 (unnamed), 1987(Clarks
Fire), 1999 (Bucks Fire), 2020
(twice – Bear Fire, North
Complex Fire), 2021 (three –
Dixie Fire, Monument Fire,
Lava Fire/Beckwourth
Complex)
6 1999 (Bucks Fire), 2008 (BTU
Lightning Complex), 2020
(twice – Bear Fire, North
Complex Fire), 2021 (twice –
Dixie Fire, Lava
Fire/Beckwourth Complex)
Source: Cal OES, FEMA
NCDC Events
The NCDC has tracked 15 wildfire events in the County dating back to 1993. Many more fires have occurred, but were not reported to the NCDC database.

IVCSD Events
The largest fire to affect the District was the Dixie Fire. The Dixie Fire burned from 7-13-2021 until 10- 25-2021. It affected Butte, Plumas, Lassen, Shasta, and Tehama counties. There was 1 firefighter killed and several injuries reported. The damage to property, infrastructure, and the economy in the District was

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severe. 75% of structures in Greenville were destroyed. This included the IVSCD Fire Station. It is likely that a wildfire of this magnitude could happen again in this area.

During this event, an estimated 5,000ft long, 12- inch diameter raw water supply line coming from the Round Valley Reservoir and ending at the Indian Valley Water Treatment Plant was damaged in spot locations by the Dixie wildfire. There is a location where the water supply line goes from a 12-inch diameter above ground metal line and connects to a 12-inch diameter PVC water line that was above ground in some locations and in other areas was put into an old shallow ditch that was once a wooden trough, the timbers of the trough were removed and the PVC pipe placed in the shallow ditch and the 4 x 12 rough cut timbers were cut into 4ft lengths and placed over the pipe, on an average 2ft on center. During the fire those timbers caught fire and melted the PVC supply line directly underneath them.

Additionally, flying embers from the Dixie Wildfire landed on a 267ft long section of 4 inch diameter welded HDPE raw water supply that was above ground which caused numerous pin hole size leaks in the line. The line starts at the Round Valley Reservoir and ends at the meter box which feeds the Greenville Cemetery, there was no damage to the meter or the meter box.

During this fire, many of the IVCSD water meters, hydrants, meter boxes, valves, and valve boxes were damaged in the Greenville area. FEMA funds helped cover the damages and the District worked to repair the damages.

Climate Change and Wildfire
It is likely that climate change will increase the chance of future occurrence as well as future impacts from wildfire. More information on future impacts to the District can be found in the Future Conditions/Future Development section of the Vulnerability Assessment below.

Warmer temperatures can exacerbate drought conditions. Drought often kills plants and trees, which serve as fuel for wildfires. Warmer temperatures could increase the number of wildfires and pest outbreaks, such as the western pine beetle. Cal-Adapt’s wildfire tool predicts the potential increase in the amount of burned areas for the year 2090-2099, as compared to recent (2010) conditions. This is shown in Section 4.3.16 of the Base Plan. Based on this model, Cal-Adapt predicts that wildfire risk in Plumas County will increase moderately at the end of the century. However, wildfire models can vary depending on the parameters used. Cal-Adapt does not take landscape and fuel sources into account in their model. In all likelihood, in the Plumas County Planning Area, precipitation patterns, high levels of heat, topography, and fuel load will determine the frequency and intensity of future wildfire.

Vulnerability to Wildfire
Risk and vulnerability to the District from wildfire is of significant concern. Wildfires that occur in the District occur from a variety of both natural and manmade causes. The District can be affected both by fires that start on or near District lands as well as those that start elsewhere and move into the District. In addition to burning large areas of land, air quality can be affected in the District by smoke from fires occurring inside the District as well as those from many miles away.

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The whole of the District is at some measure of vulnerability to wildfire. An assessment of a community’s vulnerability to wildfire begins with an understanding of local exposure to wildfire. This is included in the Local Concerns section below followed by a discussion of the District’s Assets at Risk to this hazard.

It is likely that a wildfire of the magnitude of the Dixie Fire could happen again in this area. Much of the area the District serves was damaged by that event. The area is still recovering today, and there is a question as to whether the rebuilding will reach the previous stock of buildings. To mitigate this hazard, the District is seeking to educate the public on how they can harden homes and businesses against embers, reduce fuel in and around the area, and preparing for this kind of disaster. The District can create defensible space, use noncombustible and fire resistant materials when building, and keep vegetation trimmed. Creating shaded fuel breaks, thinning and removal in the forest, dead tree removal, and keeping forests healthy will also reduce future wildfires. Prescribed burns can help also. Developing a community wildfire protection plan may also occur. The District continues to seek to educate the community, and seeks the ability to be housing workers that are carrying out mitigation projects.

The District received a FEMA grant for $7,000,000 for Greenville recovery and rebuilding costs resulting from the Dixie Fire.

The District noted key vulnerabilities include high property risk, potential loss of infrastructure, severe economic and social impacts. property and utility damage, impact on evacuation routes, contamination from burned materials, challenges in rebuilding and recovery; all of which are heightened by a longer dry season.

These long dry seasons can weaken the water supply for firefighting, placing increased strain on fire department resources. Of concern during these dry periods are hazardous fuels and forest management.

Also of concern to the District is the potential loss of water availability for fire suppression and/or consumption. Wastewater treatment can also be rendered inoperable when wildfire eliminates the availability of electricity. Without backup electricity generation, water and wastewater cannot be conveyed.

Water quality will also suffer if water treatment functionality is compromised. The economic impact alone to the District including the loss of function of buildings and infrastructure and the cost of reacting to these fires is a major concern.

Assets at Risk
Assets at risk from this hazard include people and populations served; structures and critical facilities; and natural, historic, and cultural resources. These are discussed in the following sections.

People and Populations
All populations (both District staff and Service Area populations) are at some vulnerability to wildfire.

Certain vulnerable populations are at greater risk to the effects of wildfire as well as smoke and air quality

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issues that wildfires bring. Vulnerable populations include the unhoused , infants and children under age five and their caregivers, the elderly (65 and older), individuals with disabilities, individuals’ dependent on medical equipment, individuals who exercise, recreate, or work (like District staff) outdoors, and individuals with impaired mobility.

Structures and Critical Facilities and Infrastructure
All structures in the District have some risk to wildfire. Wildfire presents a threat to critical facilities and infrastructure. All District assets from Table E-2 are at risk to wildfire.

Natural, Historic, and Cultural Resources
Natural, historic, and cultural resources located within areas at risk to wildfire would be vulnerable. Should a wildfire occur in the District, the impacts to natural, historic and cultural resources could be extensive and include air pollution, contamination from water runoff containing toxic products, other environmental discharges or releases from burned materials affecting soils, habitat areas, wildlife, and aquatic resources, and total destruction of natural resources. Debris and runoff from burned areas can affect reservoirs and rivers in the District. Historic and cultural resources can be damaged or destroyed and are often more vulnerable due to their older age, construction type, and lack of fire prevention infrastructure such as sprinklers.

Impacts from Wildfire
Potential impacts from wildfire include loss of life and injuries; damage to structures, critical facilities and infrastructure, and other improvements, natural and cultural resources, croplands, and timber; and loss of recreational opportunities. Out of control wildfires can have catastrophic impacts. Wildfires can cause short-term and long-term disruption to the District. Fires can have devastating effects on watersheds through loss of vegetation and soil erosion, which may impact the District by changing runoff patterns, increasing sedimentation, reducing natural and reservoir water storage capacity, and degrading water quality. Fires can also affect air quality in the District; smoke and air pollution from wildfires can be a severe health hazard. Smoke impacts may come from wildfires outside the District, as well as from within.

Although the physical damages and casualties arising from wildland-urban interface or conflagration fires may be severe, it is important to recognize that they also cause significant economic impacts by resulting in a loss of function of buildings and infrastructure. Economic impacts of loss of transportation and utility services may include traffic delays/detours from road and bridge closures and loss of electric power, potable water, and wastewater services. Schools and businesses can be forced to close for extended periods of time.

Recently, the threat of wildfire, combined with the potential for high winds, heat, and low humidity, has caused PG&E, Plumas Sierra REC, or Liberty Utilities to initiate a PSPS which can also significantly impact a community through loss of services, business closures, and other impacts associated with loss of power for an extended period. In addition, catastrophic wildfire can create favorable conditions for other hazards such as flooding, landslides, and erosion during the rainy season.

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burned, hillsides become destabilized and prone to erosion. The burnt surface soils are harder and absorb less water. When winter rains come, this leads to increased runoff, erosion, and landslides in hilly areas.

Impacts to the District include potential loss of water availability for fire suppression and/or consumption.

Wastewater treatment can also be rendered inoperable when wildfire eliminates the availability of electricity. Without backup electricity generation, water and wastewater cannot be conveyed. Water quality will also suffer if water treatment functionality is compromised. The economic impact alone to the District including the loss of function of buildings and infrastructure and the cost of reacting to these fires is a major concern.

Wildfire smoke can also have negative effects to those who live in or near a fire burn area. Smoke and air pollution from wildfires can be a severe health hazard. Significant wildfires occurring in nearby northern California communities since the previous LHMP have created significant air pollution affecting area residents. District residents have been affected by wildfire smoke and poor air quality, from fires both within the County and from those much further away.

Future Conditions
Future conditions may be affected by climate change, changes in population patterns (migration, density, or the makeup of socially vulnerable populations), and changes in land use and development. Findings on this for the IVCSD include the following:
➢ Climate change is likely to exacerbate future wildfire conditions and associated impacts and vulnerability of the District to wildfire.
➢ Population projections within the District’s service area show the population to be slightly declining. It is unknown how population patterns and demographics will change in the near future. The District may add staff, but this number would be relatively small. The District noted that it has no control over population changes within its service area. With no notable changes in populations numbers and makeup, the vulnerability of the District to a dam failure is unlikely to change. ➢ Changes in land use and development in the District are expected to be limited in the near future and thus would have possible associated wildfire impacts to the District. The area around Greenville may be rebuilt, but will most likely be built to the size of the previous development. Additional development traditionally leads to additional fires. In addition, adherence to protective building codes for new development will also assist in limiting future impacts and associated vulnerabilities of the District to this hazard. With adherence to development standards, future losses to new development should be minimal.

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Future Development
Land use planning should be proactive to address future hazard conditions. The District is currently rebuilding the Greenville fire station that was destroyed in the 2021 Dixie Fire. This is the only new development currently planned by the District. With respect to future development within its service area, new development and rebuilds continue with recovery efforts ongoing in the aftermath of the Dixie Fire.

Additional growth and development within moderate or higher fire hazard severity zones in the District would place additional assets at risk to wildfire. The District will take wildfire into account when siting new facilities. Fire hydrants, defensible space, well production, water storage, and distribution should all be considered when assessing future development. New facilities, including those built by the District and within the District service area will be built to the most current California Building standards for wildfire.

E.5 Capability Assessment
Capabilities are the programs and policies currently in use to reduce hazard impacts or that could be used to implement hazard mitigation activities. This capabilities assessment is divided into five sections:
regulatory mitigation capabilities, administrative and technical mitigation capabilities, fiscal mitigation capabilities, mitigation education, outreach, and partnerships, and other mitigation efforts.

E.5.1. Regulatory Mitigation Capabilities
Table E-15 lists regulatory mitigation capabilities, including planning and land management tools, typically used by local jurisdictions to implement hazard mitigation activities and indicates those that are in place in the IVCSD.

Note: The District does not have the authority to regulate land use and development within its jurisdiction.

Authority for promulgating and enforcing zoning, land use, and development requirements falls to counties and incorporated communities. As such development within the District’s jurisdictional boundaries will conform to the zoning and land use development ordinances and building codes of the county or incorporated community in which the District is located.

Table E-15 IVCSD’s Regulatory Mitigation Capabilities
Plans
In Place
Y/N
Does the plan address hazards? Can the plan be used to
carry out mitigation actions? When was it last updated?? Capital Improvements Plan N The District is looking to create one.

Climate Change Adaptation Plan N
Community Wildfire Protection Plan N County wide plan covers the CSD General Plan/Comprehensive
Plan/Master Plan
N
Continuity of Operations Plan N
Economic Development Plan N
Land Use Plan N
Local Emergency Operations Plan Y Emergency Response Plan

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Stormwater Management Plan N
Transportation Plan N
Other
Land Use Planning and Ordinances Y/N
Is the ordinance an effective way to reduce hazard
impacts?
Is the ordinance adequately administered and enforced?
Acquisition of land for open space and
public recreation use
N County
Building code N County
Flood insurance rate maps N County
Floodplain ordinance N County
Natural hazard-specific ordinance
(stormwater, steep slope, wildfire)
N County
Subdivision ordinance N County
Zoning ordinance N County
Other N County
How can these capabilities be expanded and improved to reduce risk? We need to develop a CIP and a master plan describing what the district does. They both need to be updated annually.

Source: IVCSD
E.5.2. Administrative/Technical Mitigation Capabilities Table E-16 identifies the District department(s) responsible for activities related to mitigation and loss prevention in the IVCSD.

Table E-16 IVCSD’s Administrative and Technical Mitigation Capabilities Administration
In
Place
Y/N
Describe capability
Is coordination effective?
Staff
Is staffing adequate to enforce regulations?
Is staff trained on hazards and mitigation?
Is coordination between agencies and staff effective?
Chief Building Official Y Plumas County, Michael Coelho Civil Engineer, including dam and levee
safety
N N/A
Community Planner Y Plumas County Planning
Emergency Manager Y Plumas County office of emergency services Floodplain Administrator Y Plumas County
GIS Coordinator Y Plumas County Planning
Planning Commission Y Plumas County Planning

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Other
Technical Y/N
Has capability been used to assess/mitigate risk in the past?
Grant writing N unknown
Hazard data and information Y Plumas County, FEMA, State of CA GIS analysis Y Plumas County Planning
Mutual aid agreements Y Chester PUD, Yes
Other
How can these capabilities be expanded and improved to reduce risk? Indian Valley CSD is in Greenville CA. Greenville is unincorporated so most of these resources come from Plumas County. Our jurisdiction needs improvement in every category. If we had more mutual aid agreements with surrounding districts, we would all have more resources to use for mitigation. If we had GIS we could have accurate mapping of our service area done and be more prepared for hazards and know exactly where our potential weak areas are. Historical hazard information would be helpful to have to study to help prepare and mitigate future hazards. Most of the grants we apply for are done by staff. If we had an experienced grant writer on staff, we might have better access to grants and spend less time on the applications which would save district resources.

Source: IVCSD
E.5.3. Fiscal Mitigation Capabilities
Table E-17 identifies financial tools or resources that the District could potentially use to help fund mitigation activities.

Table E-17 IVCSD’s Fiscal Mitigation Capabilities
Funding Resource
In Place
Y/N
Has the funding resource been used in past
and for what type of activities?
Could the resource be used to fund future
mitigation actions?
Capital improvements project funding N No. Yes could be used in future Community Development Block Grant N No. Yesa could be used in future Federal funding programs (non-FEMA) Y Yes. Rebuilding after Dixie Fire Fees for water, sewer, gas, or electric services Y We charge the community for water & sewer Impact fees for new development N No. Yes could be used in future State funding programs Y We have received state funding for disaster recovery
Stormwater utility fee N Yes. Could be used in future
Other
How can these capabilities be expanded and improved to reduce risk? Identify funding sources to develop CIP, identify funding sources for audits and other fiscal resources.

Source: IVCSD

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E.5.4. Mitigation Education, Outreach, and Partnerships Table E-18 identifies education and outreach programs and methods already in place that could be/or are used to implement mitigation activities and communicate hazard-related information.

Table E-18 IVCSD’s Mitigation Education, Outreach, and Partnerships Program/Organization
In Place
Y/N
How widespread are each of these in your
community?
Community newsletters Y We are working on a grant for transparency & community communication
Hazard awareness campaigns (such as Firewise,
Storm Ready, Severe Weather Awareness Week,
school programs, public events)
N
Local news Y We post on our website and in the Plumas Sun Organizations that interact with underserved and
vulnerable communities
Y Outreach to veterans and low income
community members
Social media Y Not updated regularly
How can these capabilities be expanded and improved to reduce risk? Educating the community on mitigation can help us prepare for hazards and possibly not have as devastating effect.

All of the above items help with this. IVCSD is applying for a grant to help with communication with the community.

Source: IVCSD
E.5.5. Other Mitigation Efforts
The District has many other completed or ongoing mitigation projects/efforts that include the following:
➢ Put a dam EAP together along with inundation mapping. ➢ Greenville Water System Planning Report was put together in 2019. ➢ The District has an Emergency Response Plan for the Greenville and Crescent Mills Water systems. ➢ Cutting trees and brush and debris clearing
E.6 Mitigation Strategy
E.6.1. Mitigation Goals and Objectives
The IVCSD adopts the hazard mitigation goals and objectives developed by the HMPC and described in Chapter 5 Mitigation Strategy.

E.6.2. NFIP Mitigation Strategy
The District does not participate in the NFIP, as it is not an eligible participant. Many of the District’s projects work to reduce impacts from flooding thus furthering the objectives of the NFIP.

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Local Hazard Mitigation Plan Update
January 2026
E.6.3. Mitigation Actions
The Planning Team for the IVCSD identified and prioritized the following mitigation actions based on the risk assessment. Background information and information on how each action will be implemented and administered, such as ideas for implementation, responsible office, potential funding, , and timeline are also included. The following hazards were considered a priority to the District for purposes of mitigation action planning based on criteria detailed in Chapter 5:
➢ Dam Failure
➢ Drought & Water Shortage (w/tree mortality)
➢ Earthquake
➢ Floods: 1%/0.2% annual chance (w/levee failure)
➢ Floods: Localized Stormwater
➢ Landslide, Mudslide, and Debris Flow
➢ Severe Weather: Heavy Rain and Storms (Wind, Hail, Lightning) ➢ Wildfire (w/smoke and air quality)
Non-priority hazards to the District for mitigation planning include:
➢ Agricultural Hazards (Severe Weather/Pests/Invasive Species) ➢ Climate Change
➢ Hazardous Materials Transport
➢ Severe Weather: Extreme Cold, Freeze, and Snow (w/avalanche) ➢ Severe Weather: Extreme Heat
➢ Severe Weather: High Winds and Tornado
➢ Volcano
It should be noted that many of the projects submitted by each jurisdiction in Table 5-4 in the Base Plan benefit all jurisdictions whether or not they are the lead agency. Further, many of these mitigation efforts are collaborative efforts among multiple local, state, and federal agencies. In addition, the countywide public outreach action, as well as many of the emergency services actions, apply to all hazards and jurisdictions regardless of hazard priority. Collectively, this LHMP’s multi-jurisdictional mitigation strategy includes only those actions and projects which reflect the actual priorities and capacity of each jurisdiction to implement over the next 5-years covered by this plan. It should further be noted, that each jurisdiction has focused on identifying those mitigation actions and projects to address their priority hazards, which are both realistic and reasonable for them to implement for this 5-year planning process, and would like to preserve their right to modify hazard priorities should future projects be identified where the implementing jurisdiction has the future capacity to implement.

Mitigation Actions
Action 1. Public Outreach Project
Hazards Addressed: Multi-hazard (Dam Failure, Drought & Water shortage, Earthquake, Floods:
1%/0.2% annual chance, Floods: Localized Stormwater, Landslide, Mudslide, and Debris Flow, Severe Weather: Heavy Rain and Storms (Wind, Hail, Lightning), Wildfire (w/smoke and air quality))

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Plumas County IVCSD Annex E-68
Local Hazard Mitigation Plan Update
January 2026
Goals Addressed: 1, 2, 3, 4, 5, 6, 7, 8, 9
Issue/Background (Problem Statement): Educating the public on potential hazards that effect our community is paramount. Actions taken in this area to enhance public knowledge will lead to greater mitigation efforts within the community as a whole.

Project Description: Partnering with local resources (Cal OES, Plumas County Sheriff’s Office, and others), the project will offer a variety of public education outreach efforts. Public education including but not limited to:
➢ Potential hazards and high hazard areas
➢ Property owners personal mitigation measures related to natural hazards specific to community and personal property
➢ Local and Plumas County emergency evacuation plan
➢ Living with fire, fire safe requirements, home hardening, etc. ➢ Forecasting information
➢ Hazard warning notification
➢ Emergency shelter locations
Other Alternatives: No outreach.

Existing Planning Mechanism(s) through which Action Will Be Implemented: None. The District is working on a grant for public outreach and transparency.

Responsible Office/Partners: IVCSD General Manager
Benefits (Losses Avoided): Build trust & relationships among community members, empower residents to act, and facilitate long term resilience.

Potential Funding (Local Budgets, Grant Funds, etc.): State (CAL FIRE, CA DWR, and others), FEMA HMA funding, CSD Operating Budget
Timeline: 1- 5 years
Project Priority (High, Medium, Low): High
Action 2. Dam Failure Mitigation and/or Replacement
Hazards Addressed: Dam Failure, Severe Weather: Heavy Rains and Storms, Flood: 1%/0.2% Annual Chance
Goals Addressed: 1, 2, 3, 4, 5, 6, 7, 8, 9
Issue/Background (Problem Statement): If the dam (which is owned by the District) fails at Bidwell Lake, the entire town of Greenville, CA could be under water in 17 minutes.

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Project Description: Repair/rebuild this dam and make sure it is retrofitted and upgraded to address all hazards of concern.

Other Alternatives: None
Existing Planning Mechanism(s) through which Action Will Be Implemented: The District will need to do a study and implement the findings. There is an inundation map and inspection reports.

Responsible Office/Partners: IVCSD General Manager
Benefits (Losses Avoided): Reduced property damage, reduced injury & loss of life Potential Funding (Local Budgets, Grant Funds, etc.): HHPD funding, state grants (CA DWR, DSOD), and FEMA HMA FEMA HMA funding).

Timeline: 1-5 years
Project Priority (High, Medium, Low): High
Action 3. IVCSD Secondary Water Source Project and Storage Hazards Addressed: Drought and Water Shortage
Goals Addressed: 1, 2, 3, 4, 5, 6, 7, 8, 9
Issue/Background (Problem Statement): IVCSD only has 1 water source. If anything goes wrong with the primary source, there is no backup. If there is a fire and the primary source is compromised, there is no easily accessible secondary source and not enough storage if there is a delay in repairing the primary source Project Description: Drill a secondary well, additional water storage tanks and water treatment plant for backup water source for Greenville, CA.

Other Alternatives: Bidwell Lake could be a source for Ag water but there is no treatment plant for the water to be used for drinking water and we also need more water storage.

Existing Planning Mechanism(s) through which Action Will Be Implemented: We need to do a study and evaluate and implement the findings from the study
Responsible Office/Partners: IVCSD General Manager
Benefits (Losses Avoided): Fire mitigation, extra storage in case of a problem with wells. Improved resilience and ensuring a more reliable water supply. More on hand water storage would be invaluable during wildfire season. Increased resilience to infrastructure. Support for community growth and economic stability.

Potential Funding (Local Budgets, Grant Funds, etc.): State (CA DWR and State Water Board) and FEMA HMA mitigation funds.

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Plumas County IVCSD Annex E-70
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January 2026
Timeline: 5-year plan beginning in 2026 to 2031
Project Priority (High, Medium, Low): Medium
Action 4. Earthquake Mitigation
Hazards Addressed: Earthquake, Dam Failure
Goals Addressed: 1, 2, 3, 4, 5, 6, 7, 8, 9
Issue/Background (Problem Statement): An earthquake could cause dam failure and flood Greenville.

Project Description: Evaluate District facilities for seismic concerns and harden facilities as necessary.

Retrofitting homes & businesses, public infrastructure strengthening such as retrofitting or rebuilding the dam
Other Alternatives: None
Existing Planning Mechanism(s) through which Action Will Be Implemented: Need to conduct a study and implement the findings
Responsible Office/Partners: IVCSD General Manager
Benefits (Losses Avoided): Mitigate property damage, injuries and loss of life Potential Funding (Local Budgets, Grant Funds, etc.): State (CGS) and federal (FEMA HMA funding) Timeline: 1-5 years
Project Priority (High, Medium, Low): High
Action 5. Landslide, Mudslide, & Debris Flow Mitigation Hazards Addressed: Landslides, Mudslides, & Debris Flow; Heavy Rains and Storms, Flood: 1%/0.2% Annual Chance, Flood: Localized Stormwater Flooding
Goals Addressed: 1, 2, 3, 4, 5, 6, 7, 8, 9
Issue/Background (Problem Statement): Landslides, mudslides & debris flow significantly impact transportation and the economy. This occurred during the flooding in 2017.

Project Description: Post-fire erosion control, watershed and drainage management, Long term planning and community resilience will be sought.

Other Alternatives: Decentralized stormwater management such as micro-basins, wattles & fiber rolls

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Plumas County IVCSD Annex E-71
Local Hazard Mitigation Plan Update
January 2026
Existing Planning Mechanism(s) through which Action Will Be Implemented: We need to conduct a study and implement findings
Responsible Office/Partners: IVCSD General Manager
Benefits (Losses Avoided): Reduction in property damage, economic impact, injuries, loss of life Potential Funding (Local Budgets, Grant Funds, etc.): State (CGS) and federal (FEMA HMA funding) Timeline: 1-5 years
Project Priority (High, Medium, Low): high
Action 6. Severe Weather Mitigation
Hazards Addressed: Severe Weather: Heavy Rains & Storms; Flood: 1%/0.2% Annual Chance, Flood:

Localized Stormwater Flooding; Landslides, Mudslides, and Debris Flows Goals Addressed: 1, 2, 3, 4, 5, 6, 7, 8, 9
Issue/Background (Problem Statement): Infrastructure is damaged & overwhelmed by heavy rains and storms. Areas of the District are subject to localized flooding and increased erosion and landslide risk during these times.

Project Description: Erosion and soil stabilization, stormwater and drainage management, watershed and river restoration, community and property resilience
Other Alternatives: Building elevation and retrofitting Existing Planning Mechanism(s) through which Action Will Be Implemented: The District desires to do a study and implement the findings.

Responsible Office/Partners: IVCSD General Manager
Benefits (Losses Avoided): Reduction in property damage, injuries, loss of life.

Potential Funding (Local Budgets, Grant Funds, etc.): State (CA DWR, CAL FIRE grants) and federal (FEMA HMA
Timeline: 1-5 years
Project Priority (High, Medium, Low): medium
Action 7. Wildfire Mitigation
Hazards Addressed: Wildfire

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Plumas County IVCSD Annex E-72
Local Hazard Mitigation Plan Update
January 2026
Goals Addressed: 1, 2, 3, 4, 5, 6, 7, 8, 9
Issue/Background (Problem Statement): The Dixie fire significantly impacted the businesses, economy, and entire way of life for residents in Greenville CA
Project Description: Immediate post-fire hazard reduction, resilient rebuilding & hardening Other Alternatives: Post fire watershed restoration, integrated fuels management, prescribed burns, strategic grazing
Existing Planning Mechanism(s) through which Action Will Be Implemented: The District will conduct a study and implement findings
Responsible Office/Partners: IVCSD General Manager
Benefits (Losses Avoided): Property damage, total loss of property, injuries, loss of life Potential Funding (Local Budgets, Grant Funds, etc.): State (CAL FIRE) and federal (FEMA HMA funding)
Timeline: 1-5 years
Project Priority (High, Medium, Low): High

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Plumas County PC Annex F-1
Local Hazard Mitigation Plan Update
January 2026
Annex F Plumas Corporation
F.1 Introduction
This Annex details the hazard mitigation planning elements specific to the Plumas Corporation (Plumas Corp or Corp), a new participating jurisdiction to the 2026 Plumas County Local Hazard Mitigation Plan (LHMP) Update. This Annex is not intended to be a standalone document but appends to and supplements the information contained in the Base Plan document. As such, all sections of the Base Plan, including the planning process and other procedural requirements apply to and were met by the Corp. This Annex provides information specific to Plumas Corp, with a focus on providing additional details on the planning process, risk assessment, and mitigation strategy for this jurisdiction.

F.2 Planning Process
As described above, Plumas Corp followed the planning process detailed in Chapter 3 of the Base Plan. In addition to providing representation on the Plumas County Hazard Mitigation Planning Committee (HMPC), the Corp formulated their own internal planning team to support the broader planning process requirements. Internal planning participants, their positions, and how they participated in the planning process are shown in Table F-1. Additional details on Plan participation and District representatives are included in Appendix A.

Table F-1 Plumas Corp – Planning Team
Name Position/Title How Participated
Gia Martynn Executive Director,
Plumas Corporation
Led overall planning effort for the District, coordinated District responses for hazard identification and mitigation actions. Attended meetings.

Jim Wilcox Senior Executive
Advisor, Plumas
Corporation
Provided historical hazards to the LHMC, assisted in developing District responses for hazard identification and mitigation actions.

Attended meetings.

Jeanie Hinds Watershed
Restoration Project
Manager, Plumas
Corporation
Assisted in developing District responses for mitigation actions Marty Walters PCFSC County
Coordinator, Plumas
Corporation
Attended meetings, provided hazard data and developed mitigation actions
Source: Plumas Corp

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Plumas County PC Annex F-2
Local Hazard Mitigation Plan Update
January 2026
F.3 District Profile
The community profile for the Plumas Corp is detailed in the following sections. Figure F-1 displays a District map and the location of Plumas Corp within Plumas County. As shown, the Corp’s boundaries are the same as the County’s.

Figure F-1 Plumas Corp
F.3.1. Overview and Background
Originally chartered in 1983 as a private, non-profit, public benefit organization. Plumas Corporation’s 1983 mission was to “promote the orderly and beneficial expansion of the economic base of Plumas County for the common good and general welfare of the residents”. Now, the primary mission of Plumas Corporation has evolved from a focus on traditional economic development to watershed restoration and health as a key element of a prosperous community.

In 1992, the organization contracted with Plumas County to carry out tourism and promotional activities, as part of their economic development program. In addition, Plumas Corporation was asked to provide fiscal sponsorship for the activities of the Feather River Coordinated Resources Management group (FRCRM), the Quincy Library Group (QLG), and the Plumas County Fire Safe Council (PCFSC). Budget

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Plumas County PC Annex F-3
Local Hazard Mitigation Plan Update
January 2026
constraints in 2011 led Plumas County to terminate their tourism contract, resulting in the Corporation being unable to sustain its traditional economic development program. The Corporation downsized to focus on the FRCRM and PCFSC programs.
➢ The FRCRM created a legacy of watershed stewardship that is commensurate with national, regional, and state-wide watershed management goals and strategies outlined in the National Fish and Wildlife Foundation’s Sierra Nevada Meadow Restoration Business Plan, the Upper Feather River Integrated Regional Water Management Plan (IRWMP), and California’s Water Action Plan. With the FRCRM’s new focus, Plumas Corporation’s project base now encompasses all of the Sierra Nevada and is available to provide watershed restoration services throughout the western United States. ➢ The PCFSC is a grassroots, 501(c)(3) non-profit community organization dedicated to supporting and promoting fire-adapted communities. The work is entirely funded through grant awards and community donations. Local support helps strengthen wildfire resilience and preparedness. The mission of the Plumas County Fire Safe Council is to reduce the loss of natural and manmade resources caused by wildfire through pre-fire activities.

Relationship Between Plumas Corporation and the Plumas County Fire Safe Council Plumas Corp is a non-profit organization established in California and registered as a 501(c)(3) tax-exempt entity with the U.S. Internal Revenue Service. Through a Memorandum of Understanding, Plumas Corporation has served as PCFSC’s, a separate California non-profit organization, fiscal agent since 2002.

Staffing, financial, and grant management of PCFSC’s operations are executed by Plumas Corporation, which reports to and works closely with the PCFSC’s Board of Directors.

Since the Plumas Corp boundaries are the same as the County, the climate, geography, and topography of the Corp are the same as those in the Base Plan.

F.4 Risk Assessment
As defined by FEMA, risk is a combination of hazard, vulnerability, and exposure. “It is the impact that a hazard would have on people, services, facilities, and structures in a community and refers to the likelihood of a hazard event resulting in an adverse condition that causes injury or damage.” The Plumas Corp risk assessment identifies and profiles relevant hazards and assesses the exposure of lives, property, infrastructure, and the environment to these hazards. The process allows for a better understanding of the Corp’s potential risk and vulnerability to hazards and provides a framework for developing and prioritizing mitigation actions to reduce risk from future hazard events.

Building on the Corp Profile above, a risk assessment was performed for the Corp. This includes the following sections:
➢ F.4.1 Assets Inventory and Growth and Development Trends ➢ F.4.2 Hazard Identification
➢ F.4.3 Hazard Profiles and Vulnerability to Specific Hazards

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Plumas County PC Annex F-4
Local Hazard Mitigation Plan Update
January 2026
F.4.1. Assets Inventory and Growth and Development Trends This section provides an inventory of Plumas Corp’s total assets potentially at risk to hazards and an overview of growth and development trends. This section is broken into two parts:
➢ Asset Inventory – The assets inventory identifies the Plumas Corp’s total assets, including the people and populations; structures; critical facilities and infrastructure; community lifelines; natural, historic, and cultural resources; and economic assets and community activities of value. This data is not hazard specific, but is representative of total assets within the Corp, potentially at risk to identified hazards as discussed in Section F.4.3 Hazard Profiles and Vulnerability to Specific Hazards. ➢ Growth and Development Trends – A discussion of growth and development trends in the Corp, both current and future, is presented.

Assets Inventory
The District’s asset inventory is detailed in the following sections:
➢ People and Populations
➢ Structures
➢ Critical Facilities and Infrastructure
➢ Community Lifelines
➢ Natural, Historic, and Cultural Resources
➢ Economic Assets and Community Activities of Value
A discussion of each of these assets follows and serves as the template for the asset discussion for each hazard in Section F.4.3.

People and Populations
The most important asset within any community are the people and populations that reside in the community. People and populations in the Corp include both District staff and workers as well as those populations located within District boundaries and are served by the Corp. This section includes an inventory of past and current populations of the Corp and also discusses vulnerable populations and underserved communities as a subsection of people and populations located within the Corp and potentially at risk to hazards. Information from the Corp and other sources as detailed below form the basis of this discussion.

Historic Population Trends and Current Population
The most important asset within any community are the people and populations that reside in the Corp.

The District has 18 staff. In addition to District staff, the Corp provides services to the populations located in the entire Plumas County Planning Area, which was discussed in greater detail in Chapter 4 (including discussion on vulnerable populations). Specifically, the Corp noted the following special and vulnerable populations in the Corp:

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Plumas County PC Annex F-5
Local Hazard Mitigation Plan Update
January 2026
➢ There are vulnerable and underserved individuals/populations scattered throughout the Corp.

Communications and services for these populations can be problematic due to limited transportation routes during hazardous events. Often, landline telephones and unreliable internet are the only mode of communication away from community hubs.
➢ Plumas County has a significantly older population, with seniors making up 33% of the total population, well above the state’s average of 16.2% (U.S. Census Bureau, 2021). Additionally, 12.5% of individuals under the age of 65 in Plumas County live with a disability, compared to the state average of 7.3% (California Department of Public Health, 2020). These populations are particularly vulnerable during wildfires, often due to mobility issues that necessitate specially equipped vehicles for evacuation. Many elderly and disabled individuals rely heavily on friends, family, or public transportation, making wildfire evacuations especially challenging (American Red Cross, 2022).

Furthermore, these individuals may live in homes more susceptible to wildfire damage, as they often lack the physical ability or financial resources to implement adequate wildfire mitigation measures.

Creating defensible space and performing home hardening in line with California Public Resources Code 4291 and building code requirements can be a significant barrier (California Department of Forestry and Fire Protection [CAL FIRE], 2021).
➢ For 2023, the median household income in Plumas County was $64,946, well below the state’s median of $96,334 (California Economic Development Department, 2023). Additionally, approximately 12.7% of Plumas County residents live below the poverty line, further limiting their ability to invest in fire preparedness and recovery measures (U.S. Census Bureau, 2021).

Structures and Critical Facilities
This section considers Plumas Corp’s assets at risk, with a focus on key District assets such as critical facilities and infrastructure, and other District assets and their values. With respect to District assets, their primary asset is considered a critical facility as defined for this Plan. Critical facilities are defined for this Plan as:

Any facility, including without limitation, a structure, infrastructure, property, equipment or service, that if adversely affected during a hazard event may result in severe consequences to public health and safety or interrupt essential services and operations for the community at any time before, during and after the hazard event.

A critical facility is classified by the following categories: (1) Essential Services Facilities: (2) At-Risk Populations Facilities, and (3) Hazardous Materials Facilities. Table F-2 lists critical facilities and other District assets identified by the Corp Planning Team as important to protect in the event of a disaster.

Plumas Corp’s physical assets, valued at over $5 million, consist of structures and infrastructure to support the Corp’s operations.

Table F-2 Plumas Corp Critical Facilities and Infrastructure, and Other District Assets Name of Asset Facility Type Replacement
Value
Which Hazards
Pose Risk
Building – 424 N. Mill Creek Rd/47
Trilogy Lane
Office space for Plumas Corp, PCFSC, and
other community organizations
$5,000,000 Fire and Localized
Flooding
Total $5,000,000
Source: Plumas Corp

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Plumas County PC Annex F-6
Local Hazard Mitigation Plan Update
January 2026
Community Lifelines
Assessing the vulnerability of the Plumas Corp to natural hazards and disasters also involves reviewing and inventorying the community lifelines in place that could be affected. It is important to include these items in hazard discussions as the continuous operation of critical government and business functions is essential to human health and safety, property protection, and economic security. The importance of community lifelines is discussed below:
➢ Lifelines are the most fundamental services in the community that, when stabilized, enable all other aspects of society to function.
➢ FEMA has developed a method for objectives-based response that prioritizes the rapid stabilization of Community Lifelines after a disaster.
➢ The integrated network of assets, services, and capabilities that provide lifeline services are used dayto-day to support the recurring needs of the community and enable all other aspects of society to function.
➢ When disrupted, decisive intervention (e.g., rapid re-establishment or employment of contingency response solutions) is required to stabilize the incident.

Community lifelines, as defined by FEMA, include the following:
➢ Safety and Security – Law Enforcement/Security, Fire Service, Search and Rescue, Government Service, Community Safety
➢ Food, Hydration, Shelter – Food, Water, Shelter, Agriculture ➢ Health and Medical – Medical Care, Public Health, Patient Movement, Medical Supply Chain, Fatality Management
➢ Energy – Power Grid, Fuel
➢ Communications – Infrastructure, Responder Communications, Alerts Warnings and Messages, Finance, 911 and Dispatch
➢ Transportation – Highway/Roadway/Motor Vehicle, Mass Transit, Railway, Aviation, Maritime ➢ Hazardous Material – Facilities, HAZMAT, Pollutants, Contaminants ➢ Water Systems – Potable Water Infrastructure, Wastewater Management It should be noted that these community lifelines are all in place and functional as part of regular government operations in the Plumas County Planning Area serving as a partnership between the city, local special districts and agencies, and Plumas County. Due to its more rural nature, there is an interplay in community lifelines between all jurisdictions in the County. Most all of the Corp’s community lifelines overlap with the Planning Area’s. It should also be noted that these lifelines collectively include many of the critical facilities and infrastructure assets inventoried for this LHMP, including the assets owned by the Corp. As such, specific information on these community lifelines in the Corp and how they may be affected by a hazard event or disaster are discussed in the Base Plan.

Natural, Historic, and Cultural Resources
Assessing the vulnerability of the Plumas Corp to natural hazards and disasters also involves inventorying the natural, historic, and cultural assets of the area. This step is important for the following reasons:

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Plumas County PC Annex F-7
Local Hazard Mitigation Plan Update
January 2026
➢ Environmental and natural resources add to a community’s identity and quality of life. They also help the local economy through agriculture, tourism, and recreation. They support ecosystem services, such as clean air and water.
➢ Conserving the environment may help people mitigate risk. It can also protect sensitive habitats, develop parks and trails, and build the economy.
➢ The community may decide that these types of resources warrant a greater degree of protection due to their unique and irreplaceable nature and contribution to the overall economy. ➢ If these resources are impacted by a disaster, knowing so ahead of time allows for more prudent care in the immediate aftermath, when the potential for additional impacts are higher. ➢ The rules for reconstruction, restoration, rehabilitation, and/or replacement are often different for these types of designated resources.
➢ Natural resources can have beneficial functions that reduce the impacts of natural hazards, such as wetlands and riparian habitat, which help absorb and attenuate floodwaters.

Natural Resources
A variety of natural resources are located within Plumas Corp’s boundaries. These natural resources parallel that of Plumas County as a whole. Information can be found in Section 4.2.1 of the Base Plan.

Historic and Cultural Resources
A variety of historic and cultural resources are located within Plumas Corp’s boundaries. These historic and cultural resources parallel that of Plumas County as a whole. Information can be found in Section 4.2.1 of the Base Plan.

Economic Assets and Community Activities of Value
Assessing the vulnerability of the Plumas Corp to natural hazards and disasters also involves inventorying the economic assets and community activities of value in the Corp.

Economic Assets
After a disaster, economic resiliency is one of the major drivers of a speedy recovery. Each community has specific economic drivers. Economic assets for the County were discussed in Section 4.2.1 of the Base Plan and are assumed to be the same or similar for the Corp. In addition, the Corp noted that the economy of Plumas County is strongly anchored in its forest‑based sectors, with logging as the dominant force. Two major sawmills—Sierra Pacific Industries in Quincy and Collins Pine in Chester—lead the way, collectively processing over 250 million board feet of timber annually and employing hundreds of local residents in tasks ranging from harvesting and milling to trucking. Sierra Pacific Industries alone runs two Quincy mills staffed by approximately 300 employees and manages over 2.4 million acres across California, Oregon, and Washington. Concurrently, Collins Pine, with its Chester mill, employs around 122 people and sustainably manages 135,000 acres using uneven‑aged forestry—which helps ensure long-term productivity through selective harvesting.

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Plumas County PC Annex F-8
Local Hazard Mitigation Plan Update
January 2026
The health of Plumas County’s forests directly influences the timber industry’s longevity. Salvage logging of fire‑damaged timber is economically viable only within about two years post-fire, before rot and insect infestation significantly reduce wood quality.

Therefore, maintaining healthy, unburned or “responsibly” burned forest stands is essential not just for immediate production, but for future timber supply. Timely fire prevention, rapid response, and sustainable forest management are crucial to preserving the industry's economic base in Plumas County.

Ranching and associated agricultural endeavors play a vital role in the economy of Plumas County, relying on essential resources such as clean water, adequate grazing land, and healthy air quality to sustain livestock operations. The region’s ranching industry is especially dependent on water quality, as much of the local agriculture relies on access to natural water sources for irrigation and livestock consumption. Recent wildfires have had significant impacts on these resources, particularly affecting water quality by introducing contaminants such as ash and sediment into local rivers and streams. Furthermore, fires have disrupted grazing areas on public lands, reducing the availability of affordable pasture for ranchers. These effects are compounded by the challenges of post-fire restoration, as public lands managed by federal and state agencies often require extensive recovery efforts before they can be reopened for grazing. It's not just the immediate loss of grazing, but the long-term impact on soil health and water availability that has the biggest impact on this local industry.

Recreation is another significant contributor to the economy of Plumas County, attracting thousands of visitors each year. The region’s diverse landscape—featuring expansive forests, mountain lakes, and scenic rivers—provides year-round opportunities for outdoor activities such as hiking, fishing, boating, and skiing.

Plumas County’s natural beauty draws eco-tourists, outdoor enthusiasts, and sports lovers, directly benefiting local businesses, tourism services, and infrastructure. Notable recreational hotspots like the numerous lakes in the area, the Feather River, the Lakes Basin Recreation area, and Plumas Eureka State Park offer a range of activities, while the county’s extensive trail systems and campgrounds support both day-trippers and overnight visitors (Plumas County Tourism, 2021). There are a number of large cycling events that are attended by thousands of participants each year. The economic impact of recreation extends beyond the spending in sectors like hospitality, retail, and transportation; it also supports significant employment in tourism-related fields, such as guiding services, hospitality management, and park services (California Economic Development Department, 2022). According to a report from the Outdoor Industry Association, outdoor recreation generates over $28 billion in consumer spending each year in California, underscoring the sector’s role in driving local economies in rural areas like Plumas (Outdoor Industry Association, 2020).

Community Activities of Value
Inventorying economic assets in the Corp and their vulnerability to natural hazards and disasters also involves inventorying activities that have value to the community. This includes activities that are important to a community, like long-standing traditions such as a festival or fair or other activities that bring money into the communities such as sports tournaments and other recreational activities. Community Activities of Value for the County were discussed in Section 4.2.1 of the Base Plan and are assumed to be the same or similar for the Corp.

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Plumas County PC Annex F-9
Local Hazard Mitigation Plan Update
January 2026
Growth and Development Trends
As part of the planning process, the Corp looked at changes in growth and development, both current and future, and examined these changes in the context of hazard-prone areas, and how the changes in growth and development affect loss estimates and vulnerability over time. This inventory section details future development/redevelopment projects that are likely to occur over the next five years covered by this 2026 LHMP. For Districts, this generally includes the following:
➢ Construction/development projects related to adding new District facilities, infrastructure, land acquisition, etc.
➢ Plans for expansion or build out of the Corp’s service area, including new service hookups, and other District functions related to where the Corp will be expanding services.

Population Trends and Projections
General growth in the Corp parallels that of the Plumas County Planning Area as a whole. Information can be found in Section 4.2.1 of the Base Plan. The District may also consider modifying the number and types of new staff over the next five years to support District objectives.

Future Development Areas
As previously described, Plumas Corp is a unique District in the Plumas County Planning Area. With the exception of its office building, it does not own any facilities or properties. The primary mission of the Plumas Corp’s mission has evolved from a focus on traditional economic development to watershed restoration and health as a key element of a prosperous community. As such, the Corp has no plans to acquire or develop new properties or add structures to support their District objectives. Further, the Corp has no control over future development within its District boundaries. However, Plumas Corp provided additional information regarding potential development within the County. Specifically, growth in the County has been relatively flat for a number of years. Most new home construction is in existing approved areas with the highest concentration being in the Town of Greenville which was all but lost during the 2021 Dixie Fire. One possible project is the Moonlight-Superior Project, envisioned as an open-pit copper mine in the headwaters of Lights Creek. There is considerable community concern related to ground and surface water quality and flood hazards associated with this potential development project.

Hazard Profiles and Vulnerability Assessment
Each hazard is profiled in the following format:
➢ Hazard Profile – A hazard profile is included for each hazard. This includes information on:
✓ Hazard Overview – A general discussion of the hazard and related issues is detailed here. ✓ Location and Extent – Location is the geographic area within the Corp that is affected by the hazard. Extent is the expected range of intensity for each hazard. These are discussed in specific detail for mapped hazards, and in more general detail for those hazards that do not have discrete mapped hazard areas.
✓ Past Occurrences – Past occurrences are discussed for each hazard. A discussion of disaster declarations is included in each hazard section. NCDC events are also discussed. Other past

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Plumas County PC Annex F-10
Local Hazard Mitigation Plan Update
January 2026
occurrences data specific to the Corp follow the disaster declarations and NCDC events for each hazard.
✓ Climate Change – This section contains the effects of climate change (as applicable). The possible influence of climate change on the hazard is discussed.

After the hazard profile, a vulnerability assessment is presented. As part of the vulnerability assessment, an estimate of the vulnerability of the Corp to each identified hazard, in addition to the estimate of risk of future occurrence, is provided in each of the hazard-specific sections. Vulnerability is measured in general, qualitative terms and is a summary of the potential impact based on past occurrences, spatial extent, and damage and casualty potential. It is categorized into the following classifications:
➢ Extremely Low—The occurrence and potential cost of damage to life and property is very minimal to nonexistent.
➢ Low—Minimal potential impact. The occurrence and potential cost of damage to life and property is minimal.
➢ Medium—Moderate potential impact. This ranking carries a moderate threat level to the general population and/or built environment. Here the potential damage is more isolated and less costly than a more widespread disaster.
➢ High—Widespread potential impact. This ranking carries a high threat to the general population and/or built environment. The potential for damage is widespread. Hazards in this category may have occurred in the past.
➢ Extremely High—Very widespread with catastrophic impact.

After this classification, a general discussion of hazard vulnerabilities occurs. This is done in the following format:
➢ Vulnerability Overview – A general discussion of the hazard vulnerability and related issues is detailed here.
➢ Local Concerns – This includes District provided information on how the Corp is uniquely affected by or vulnerable to each hazard.
➢ Assets at Risk – A discussion of the assets at risk follows, presented in the same order as in Section F.4.1 above, with a few exceptions. This includes sections on: People and Populations; Structures and Critical Facilities and Infrastructure; and Natural, Historic, and Cultural Resources. These are discussed in specific terms for mapped hazards, and in more general terms for those hazards that are unmapped. Sections on Community Lifelines and Economic Assets and Community Activities of Value are not included in the Sections below, as they are common to all jurisdictions and are fully covered in Section F.4.1 above and Chapter 4 of the Base Plan.
➢ Impacts – A discussion on hazard impacts follows. Impacts describe how each hazard can affect the Corp, its assets, and the ability to provide continued and reliable services. The type and severity of impacts reflect both the potential magnitude of the hazard and the vulnerability of the asset. ➢ Future Conditions/Future Development – A discussion of how future conditions and future development will affect or influence each hazard over time is also included. This considers both new District assets and improvements as well as any changes within their jurisdictional boundaries.

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Plumas County PC Annex F-11
Local Hazard Mitigation Plan Update
January 2026
F.4.2. Hazard Identification
The Plumas Corp identified the hazards that affect the Corp and summarized their location, extent, likelihood of future occurrence, potential magnitude, and significance (or priority of a hazard) specific to the Corp.

Note: Those hazards identified as a high or medium significance in Table F-3 are considered priority hazards for mitigation planning. Those hazards that occur infrequently or have little or no impact in the Corp were determined to be of low significance and not considered a priority hazard to the Corp.

Significance was determined based on the hazard profile, focusing on key criteria such as frequency, extent, and resulting damage, including deaths/injuries and property, natural and cultural resources, and economic damage. The ability of a jurisdiction to reduce losses through implementation of existing and new mitigation measures was also considered as to the significance and priority of a hazard. This assessment was used to prioritize those hazards of greatest significance, enabling the Corp to focus resources where they are most needed.

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Plumas County PC Annex F-12
Local Hazard Mitigation Plan Update
January 2026
Table F-3 Plumas Corp—Hazard Identification Assessment
Hazard
Geographic
Extent
Likelihood of
Future
Occurrences
Magnitude/
Severity Significance
Climate
Change
Influence
Ag Hazard: Severe Weather /
Insects/Pests
Extensive Highly Likely Critical Medium Medium
Climate Change (adaptation) Extensive Likely Limited Medium Low Dam Failure – – – Low Low
Drought & Water Shortage (w/tree
mortality)
Extensive Likely Limited Medium High
Earthquake – – – Low Low
Flood: 1%/0.2% annual chance
(w/levee failure)
Significant Occasional/Unlikely Critical High Medium
Flood: Localized Stormwater Significant Highly Likely Negligible Medium Medium HazMat Transportation – – – Low Low
Landslide, Mudslide, and Debris
Flow
– – – Low Medium
Severe Weather: Extreme Cold,
Freeze, and Snow (w/avalanche)
– – – Low Low
Severe Weather: Extreme Heat Extensive Highly Likely Negligible Medium High Severe Weather: Heavy Rains and
Storms
Extensive Highly Likely Limited Medium Medium
Severe Weather: High Winds and
Tornadoes
– – – Low Medium
Volcano – – – Low Low
Wildfire (w/smoke and air quality) Extensive Highly Likely Catastrophic High Medium Geographic Extent
Limited: Less than 10% of planning
area
Significant: 10-50% of planning area
Extensive: 50-100% of planning area
Likelihood of Future Occurrences
Highly Likely: Near 100% chance of
occurrence in next year, or happens
every year.

Likely: Between 10 and 100% chance of
occurrence in next year, or has a
recurrence interval of 10 years or less.

Occasional: Between 1 and 10% chance
of occurrence in the next year, or has a
recurrence interval of 11 to 100 years.

Unlikely: Less than 1% chance of
occurrence in next 100 years, or has a
recurrence interval of greater than every
100 years.

Magnitude/Severity
Catastrophic: More than 50 percent of property severely damaged; shutdown of facilities for more than 30 days; and/or multiple deaths Critical: 25-50 percent of property severely damaged; shutdown of facilities for at least two weeks; and/or injuries and/or illnesses result in permanent disability
Limited: 10-25 percent of property severely damaged; shutdown of facilities for more than a week; and/or injuries/illnesses treatable do not result in permanent disability
Negligible: Less than 10 percent of property severely damaged, shutdown of facilities and services for less than 24 hours; and/or injuries/illnesses treatable with first aid
Significance
Low: Minimal potential impact
Medium: Moderate potential impact
High: Widespread potential impact
Climate Change Influence
Low: Minimal potential impact
Medium: Moderate potential impact
High: Widespread potential impact

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Plumas County PC Annex F-13
Local Hazard Mitigation Plan Update
January 2026
F.4.3. Hazard Profiles and Vulnerability to Specific Hazards This section includes the hazard profiles and vulnerability assessment for hazards ranked of medium or high significance specific to the Plumas Corp (as identified in the Significance column of Table F-3). This section focuses on where and how the Corp is affected by their priority hazards. Chapter 4 of the Base Plan provides more detailed information about these hazards and their impacts on the Plumas County Planning Area. Methodologies for evaluating vulnerabilities and calculating loss estimates are the same as those described in Section 4.2 of the Base Plan.

Power Interruption/Power Failure: A Common Vulnerability of all Hazards An impact of almost all hazards evaluated as part of this LHMP Update relates to power shortage and/or power failures. The US power grid crisscrosses the country, bringing electricity to homes, offices, factories, warehouses, farms, traffic lights and even campgrounds. According to statistics gathered by the U.S.

Department of Energy, major blackouts are on the upswing. Incredibly, over the past two decades, blackouts impacting at least 50,000 customers have increased 124 percent. The electric power industry does not have a universal agreement for classifying disruptions. Nevertheless, it is important to recognize that different types of outages are possible so that plans may be made to handle them effectively. In addition to blackouts, brownouts can occur. A brownout is an intentional or unintentional drop in voltage in an electrical power supply system. Intentional brownouts are used for load reduction in an emergency.

Electric power disruptions can be generally grouped into two categories: intentional and unintentional.

More information on types of power disruptions can be found in Section 4.3 of the Base Plan.

Public Safety Power Shutoff (PSPS)
An intentional disruption type of power shortage/failure event has been recently implemented in California as a result of wildfires starting as a result of downed power lines or electrical equipment. This was the case for the Camp Fire in 2018. As a result, California’s three largest energy companies (including PG&E), at the direction of the California Public Utilities Commission (CPUC), are preparing all Californians for the threat of wildfires and power outages during times of extreme (fire) weather. To help protect customers and communities during extreme fire weather events, electric power may be shut off for public safety in an effort to proactively prevent wildfire. This is called a PSPS. More information on PSPS criteria can be found in Section 4.3 of the Base Plan.

In addition to PSPSs, to help prevent wildfires, electric utilities have begun to evolve safety efforts. This includes installing safety settings on powerlines in and around high fire-risk areas. These are known as Enhanced Powerline Safety Settings (EPSS), and they help prevent falling tree branches, animals and other hazards from causing a wildfire. By stopping ignitions, it helps prevent wildfires from starting and spreading. According to PG&E, if ignitions occur, the size of fires can be much smaller due to EPSS. In 2022, there was a 99% decrease in acres impacted by ignitions (as measured by fire size from electric distribution equipment (compared to the 2018-2020 average). This decrease occurred despite dry conditions.

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Plumas County PC Annex F-14
Local Hazard Mitigation Plan Update
January 2026
Local Concerns
Power outages, planned and unplanned, are frequent in the Corp. Some of the more isolated communities/locales in the Corp are more prone to unplanned and/or extended outages related to weather events, equipment failure, or wildfire. A high percentage of homes are on domestic water wells, so lack of water supplies during extended outages is a major concern, as well as food spoilage. Due to the foregoing, many individual homes and businesses have installed permanent backup generation, predominately using propane fuel. However, many community members lack the resources (~$10,000) for backup generators.

In addition, outages can affect communications, cutting off community members access to potentially critical emergency information and services.

Agricultural Hazards (Severe Weather/Pests/Invasive Species) Likelihood of Future Occurrence–Highly Likely
Vulnerability–Medium
Hazard Profile
Farming and related agricultural industries are not only important to Plumas County’s economy, but they also play a central role in the way of life of County residents and help define the character of the County.

Agriculture has always been an integral part of Plumas County and has continually grown and changed along with the County. Agriculture in the County can be affected by a variety of natural hazards. This Agricultural Hazard focuses on severe weather, as well as native and invasive species (insects, pests and weeds), all which can significantly affect the agricultural industry in the County. This hazard does not address pest and plants that cause impacts to human health, as those issues are addressed in other planning mechanisms in the County.

Agricultural losses occur on an annual basis and are often associated with severe weather events, including heavy rains, floods, heat, and drought and issues associated with insects, pests, agricultural diseases, and invasive species. Invasive species are organisms that are introduced into an area beyond their natural range and become a pest in the new environment. The 2023 State of California Multi-Hazard Mitigation Plan attributes most of the agricultural disasters statewide to drought, freeze, and insect infestations. Other agricultural hazards include fires, crop and livestock disease, insects, and noxious weeds.

Location and Extent
Agricultural hazards, including issues associated with severe weather as well as nuisance insects, pests and weeds, occur throughout the County where lands are used for farming, grazing, timber production, and other agricultural uses. The larger County has large swaths of agricultural lands. Areas of the County, such as the City of Portola and higher elevations of the County, contain fewer agricultural lands, and are thus not as greatly affected by agricultural hazards. While the City and special districts may not always be directly affected, they are indirectly affected economically when agricultural losses occur.

There is no scale that measures agricultural hazards. Agriculture in the Corp and County is at risk to many hazards: severe weather, as well as native and invasive insects, pests and weeds. Each of these has a different duration and speed of onset. Some, such as freeze, can have a short onset and a short duration.

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Plumas County PC Annex F-15
Local Hazard Mitigation Plan Update
January 2026
Drought can have a long onset and long duration. Agricultural hazards like nuisance pests and weeds can have short or long onset, and short or long durations. All agricultural losses can have a significant impact on affected communities.

Past Occurrences
Disaster Declaration History
There are no state or federal disaster declarations issued by Cal OES or FEMA. There have been 17 USDA Secretarial Disaster Declarations for the County since 2012 (as shown in the Past Occurrences in Section

4.3.6 of the Base Plan). 13 were from drought, 3 were from freeze, and 1 was from other severe weather events.

NCDC Events
The NCDC does not track agricultural events.

Plumas Corp Events
The District noted that flooding occurred in 1986, 1997, and 2017. These affected agriculture in the Corp.

The District also noted that Emergency Watershed Protection (EWP) work was undertaken in numerous locations in Plumas County after the 1986 & 1997 floods to rebuild streambanks, informal levees, and irrigation infrastructure throughout the Corp.

Climate Change and Agricultural Hazards
According to the 2021 CAS (as well as the 2024 Draft CAS), addressing climate change in agriculture will encompass reducing vulnerability through adapting to the ongoing and predicted impacts of climate.

Agriculture in California is vulnerable to predicted impacts of climate change, including less reliable water supplies, increased temperatures, and increased pests.

The 2023 California State Hazard Mitigation Plan noted that California farmers contend with a wide range of crop-damaging pests and pathogens. Continued climate change is likely to alter the abundance and types of many pests, lengthen pests’ breeding season, and increase pathogen growth rates. It also noted that change in climate can directly impact crop growth through new temperature patterns and northward shifts of pests and disease. Additionally, longer growing seasons may enable pest species to complete more reproductive cycles, which can increase severity of infestations.

Finally, the 2023 State Plan noted that temperature is not the only climatic influence on pests. For example, some insects are unable to cope in extreme drought, while others cannot survive in extremely wet conditions. Furthermore, while warming speeds up the life cycles of many insects, suggesting that pest problems could increase, some insects may grow more slowly as elevated carbon dioxide levels decrease the protein content of the leaves on which they feed.

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Plumas County PC Annex F-16
Local Hazard Mitigation Plan Update
January 2026
Vulnerability to Agricultural Hazards (Severe Weather/Pests/Invasive Species) According to historical hazard data, both severe weather affecting agriculture, and insects, pests, and weeds are an annual occurrence in the Corp. If left unchecked, severe weather, and agricultural pests and weeds can threaten native species, biodiversity, ecosystem services, recreation, water resources, agricultural and forest production, cultural resources, economies and property values, public safety, and infrastructure.

An assessment of a community’s vulnerability to this hazard begins with an understanding of local exposure to the Plumas Corp. This is included in the Local Concerns section below followed by a discussion of the Corp’s Assets at Risk to this hazard.

Local Concerns
The District has specific concerns and unique vulnerabilities regarding this hazard. These concerns form a portion of the basis for the mitigation strategy and mitigation actions that seek to reduce risk and vulnerability to this hazard. This includes:
➢ Flood related damage to fields, fences and irrigation infrastructure occurs throughout the Corp.

Flooding can bring benefits to agricultural lands. Reducing flood magnitudes and organic/mineral debris loads while flood proofing infrastructure can mitigate negatives. ➢ Grasshoppers are a nearly annual problem somewhere in the Corp. ➢ Gray wolves have become a major concern to livestock producers. ➢ Star thistle is a concern for the Corp and the County. Star thistle thrives in disturbed lands. Restoring natural hydrologic and vegetative resilience can drown/crowd out star thistle.

People and Populations
People and populations in the Corp include both District staff and workers as well as those populations located within District boundaries. Agricultural hazards have a minimal effect on people and populations in the Corp, including District staff and vulnerable populations. However, damage to crops from both severe weather and invasive and nuisance insects, pests, and weeds can cause significant increases in food prices and food insecurity among low-income communities.

Structures and Critical Facilities and Infrastructure
Structures and critical facilities and infrastructure in the Corp may be affected by agricultural hazards.

Regarding nuisance species, some species can impact vegetation and can result in stream bank instability, erosion, and increased sedimentation, impacting ground stabilization and possibly causing foundation issues for nearby structures. If species cause trees and other vegetation to die, there is an increased risk of damage to roadways, powerlines, and buildings, and increased risk to wildfire. Some nuisance plants have been shown to destabilize soil due to high densities and shallow root systems, negatively impacting nearby

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Plumas County PC Annex F-17
Local Hazard Mitigation Plan Update
January 2026
buildings and septic systems. Other nuisance plant species have been known to clog culverts and streams, increasing flooding risk. Additionally, soil that becomes unstable due to decaying vegetation can impact critical facilities that are built on or around these soils.

According to Table F-2, the Corp’s office facility is not at risk to agricultural hazards.

Natural, Historic, and Cultural Resources
Natural resources can be affected by agricultural hazards. Negative impacts of severe weather and nuisance species to natural resources include the following:
➢ Loss of wildlife habitat and reduced wildlife numbers; ➢ Loss of native plant species;
➢ Reduced livestock grazing capacity;
➢ Increased soil erosion and topsoil loss;
➢ Diminished water quality and fish habitat.

Natural, historic, and cultural resources and the severe weather that affect agriculture in the County are discussed further in other sections of this Annex.

Impacts from Agricultural Hazards: (Severe Weather/Pests/Invasive Species) The consequences of agricultural disasters to the Corp and larger Plumas County include ruined plant crops, loss of grazing lands, dead livestock, ruined feed and agricultural equipment, monetary loss, job loss, and possible multi-year effects (i.e., trees might not produce if damaged, loss of markets, food shortages, increased prices, possible spread of disease to people, and loss or contamination of animal products).

Overall, any type of severe agricultural disaster can have significant economic impacts on both the agricultural community, the Plumas Corp, and the entire Plumas County Planning Area. They can also cause significant increases in food prices to the consumer due to shortages. Under some conditions, insects that have been present and relatively harmless can become hazardous. For example, severe drought conditions can weaken trees and make them more susceptible to destruction from insect attacks.

Impacts to identified assets at risk to this hazard and the overall vulnerability of the Corp may be affected in the future by climate change, changes in population patterns (migration, density, or the makeup of socially vulnerable populations), and changes in land use and development. These are discussed in the Future Conditions/Future Development discussion below.

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Plumas County PC Annex F-18
Local Hazard Mitigation Plan Update
January 2026
Future Conditions
Future conditions may be affected by climate change, changes in population patterns (migration, density, or the makeup of socially vulnerable populations), and changes in land use and development. Findings on this for the Plumas Corp include the following:
➢ Climate change is likely to exacerbate future agricultural hazards and associated impacts and vulnerability of the Corp.
➢ Population projections within the jurisdictional boundaries of the Corp show the population to be slightly declining. It is unknown how population patterns and demographics will change in the near future. The District may add staff, but this number would be small. The District noted that it has no control over population changes within its jurisdictional boundaries. With no notable changes in populations numbers and makeup, the vulnerability of the Corp to agricultural hazards is unlikely to change.
➢ Changes in land use and development within District boundaries are expected to be limited in the near future and thus are not likely to affect agricultural impacts to the Corp. The District noted that it has no control over land use and development within its jurisdictional boundaries. With limited future growth and development occurring, the vulnerability of the Corp to agricultural hazards is unlikely to change.

Future Development
The District has no plans to acquire or develop new properties or add structures to support their District objectives. Further, the Corp noted that it has no control over future development within its District boundaries. Responsibility for growth and development within District boundaries resides with the County and the City of Portola. Since the Corp shares the same boundaries as the unincorporated County, future conditions in the Corp regarding land use, migration, population changes, and climate change are the same as those in Section 4.3.7 of the Base Plan. Future development in the Corp is not likely to have an impact on agricultural hazards in Plumas County, except to the extent that agricultural lands are taken out of production as new development occurs reducing available land for agricultural uses, including those related to farming, timber production and grazing.

Climate Change
Likelihood of Future Occurrence–Likely
Vulnerability–High
Hazard Profile
Climate change adaptation is a key priority of the State of California. The 2023 State of California MultiHazard Mitigation Plan noted that climate change is already affecting California. Sea levels have risen by as much as seven inches along the California coast over the last century, increasing erosion and pressure on the State’s infrastructure, water supplies, and natural resources. The State has also seen increased average temperatures, more extreme hot days, fewer cold nights, a lengthening of the growing season, shifts in the water cycle with less winter precipitation falling as snow, and earlier runoff of both snowmelt and

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Plumas County PC Annex F-19
Local Hazard Mitigation Plan Update
January 2026
rainwater in the year. In addition to changes in average temperatures, sea level, and precipitation patterns, the intensity of extreme weather events is also changing.

California’s Adaptation Planning Guide: Understanding Regional Characteristics (from 2017) has divided California into 11 different regions based on political boundaries, projected climate impacts, existing environmental setting, socioeconomic factors and regional designations. The District falls in the North Sierra Region. A map and climate projections for this region are shown in Section 4.3.7 of the Base Plan and include an increase in temperatures, moderate changes in rainfall, and increased risk to wildfire.

Location and Extent
Climate change is a global phenomenon. It is expected to affect the whole of the Plumas Corp, the Plumas County Planning Area, surrounding counties, and State of California. There is no scale to measure the extent of climate change. Climate change exacerbates other hazards, such as drought, extreme heat, flooding, wildfire, and others. The speed of onset of climate change is very slow. The duration of climate change is not yet known but is feared to be tens to hundreds of years.

Past Occurrences
Disaster Declaration History
Climate change has never been directly linked to any declared disasters.

NCDC Events
NCDC does not track climate change events.

Plumas Corp Events
The District noted that the change in precipitation type from snow to rain and earlier snowmelt have begun affecting forest health/fire susceptibility, while also changing water supply reliability and the character of stream channels. Climate change has led to longer periods of elevated wildfire risk and paved the way for “Mega-fires” such as the North Complex in 2020 and the Dixie Fire in 2021, which significantly impacted Plumas County. Across the western states and particularly California, these mega fires are becoming more frequent and costly due to the suppression costs as well as the overall damage to infrastructure and personal property.

Vulnerability to Climate Change
The whole of the Corp is at some measure of vulnerability to climate change. The District Planning Team has concerns that the vulnerability of the Corp to climate change will continue to increase in the future. An assessment of a community’s vulnerability to climate change begins with an understanding of local exposure to climate change. This is included in the Local Concerns section below followed by a discussion of the Corp’s assets at risk, and impacts to this hazard.

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Plumas County PC Annex F-20
Local Hazard Mitigation Plan Update
January 2026
Local Concerns
The District has specific concerns and unique vulnerabilities regarding this hazard. These concerns form a portion of the basis for the mitigation strategy and mitigation actions that seek to reduce risk and vulnerability to this hazard. Specifically, the Corp is concerned that:
➢ The principal ongoing climate change effects across the Corp entail a higher elevation permanent snow line, an earlier snow melt, a longer growing season for all plants, and warmer, particularly night-time, temperatures. This creates a greater demand (scarcity) on the finite natural soil water supply. ➢ The above climate change effects will exacerbate wildfire and tree mortality risks in the remaining unburned forest in the Corp.
➢ The above climate change effects will make forest recovery process more complicated due to the fuel type conversion that often occurs within the footprint of large, devastating fires. ➢ Without mitigation, areas that were once rich in mature and developing forests may become permanent, more flammable brush fields.
➢ Areas that were once rich in mature and developing timber often become brushfields. ➢ Loss of ecosystem resilience and its profound effects on all aspects of community health and stability.

Assets at Risk
Assets at risk from this hazard include people and populations; structures and critical facilities and infrastructure; and natural, historic, and cultural resources. These are discussed in the following sections.

People and Populations
Climate change affects people and populations within a community, especially those climate change issues related to increases in temperature over time.

While all populations (both District staff and those located within District boundaries) can be affected by temperature extremes, populations particularly vulnerable include the very old and very young, medically fragile people, people without means of shelter (and air conditioning or heat) or transportation, people who are socially isolated and other vulnerable or underserved populations (as shown in the discussion in Section F.4.1). Acclimatization to extreme temperatures and other weather extremes may help reduce impacts from these extreme events, such as from heat waves, in the healthy general population but may not be sufficient to protect those with underlying medical conditions.

Structures and Critical Facilities and Infrastructure
Climate change, on its own, does not generally impact structures. However, structures in areas of increased wildfire, drought, extreme heat, or flood areas exacerbated by the effects of climate change would be at increased risk, as described throughout this LHMP. Due to the slow onset of climate change, any structures in the Corp are expected to undergo improvements and adapt over time to a new climate normal. Also as previously mentioned, with the exception of their one office building, the Corp does not have other owned assets or structures that would be vulnerable to climate change.

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Plumas County PC Annex F-21
Local Hazard Mitigation Plan Update
January 2026
Natural, Historic, and Cultural Resources
The rivers, streams, agricultural areas, and open space areas of the Corp support rich biodiversity, including many special-status species and habitat areas. These are all at risk from the effects of climate change. In addition, if heat continues to contribute to changes in wildfire patterns, all areas (on land) of the Corp are at increased risk from fire – including natural, historic, and cultural resources. Furthermore, as climate change exacerbates the extreme heat and drought hazard, areas of wetlands in the Corp may be reduced or dry up temporarily, which could damage habitat areas for waterfowl and other species that depend on these areas.

Impacts from Climate Change
The California APG: Understanding Regional Characteristics identified the following impacts specific to the North Sierra Region in which the Corp is part of:
➢ Increased temperatures
➢ Reduced precipitation
➢ Public health – heat and air pollution
➢ Reduced agricultural productivity (e.g., wine grapes) ➢ Reduced tourism
In addition to these sources, the 2023 State of California Hazard Mitigation Plan noted that according to California’s Fourth Climate Change Assessment, the state will experience the following climate impacts:
➢ Annual average daily high temperatures are expected to rise by 2.7°F by 2040, 5.8°F by 2070, and

8.8°F by 2100 compared to observed and modeled historical conditions. These changes are statewide averages.
➢ Heat waves are projected to become longer, more intense, and more frequent. ➢ Warming temperatures are expected to increase soil moisture loss and lead to drier conditions. Summer dryness may become prolonged, with soil drying beginning earlier in the spring and lasting longer into the fall and winter.
➢ Droughts are likely to become more frequent and persistent through 2100. ➢ The strength of the most intense precipitation and storm events affecting California is expected to increase.
➢ Snowpack levels are projected to decline significantly by 2100 due to reduced snowfall and faster snowmelt.
➢ Marine layer clouds are projected to decrease.
➢ Extreme wildfires (i.e., fires larger than 24,710 acres) would occur 50 percent more frequently. The maximum area burned statewide may increase 178 percent by the end of the century.

Impacts to identified assets at risk to this hazard and the overall vulnerability of the Corp may be affected in the future by climate change (which was discussed in the hazard profile section above), changes in population patterns, and changes in land use and development. The influencing effects of these factors on this hazard are discussed further in the Future Conditions/Future Development discussion below.

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Local Hazard Mitigation Plan Update
January 2026
Future Conditions/Future Development
This section provides a discussion of how future conditions will influence or affect the hazard over time and also discusses future development relative to each hazard.

Future Conditions
Future conditions may be affected by climate change, changes in population patterns (migration, density, or the makeup of socially vulnerable populations), and changes in land use and development. Findings on this for the Corp include the following:
➢ As climate change continues to accelerate over time, climate related impacts to the Corp will continue to increase.
➢ Population projections within the jurisdictional boundaries of the Corp show the population to be slightly declining. It is unknown how population patterns and demographics will change in the near future. The District may add staff, but this number would be small. The District noted that it has no control over population changes within its jurisdictional boundaries. With no notable changes in populations numbers and makeup, the vulnerability of the Corp to this hazard is unlikely to change. ➢ Changes in land use and development in the Corp are expected to be limited in the near future and thus are not likely to affect climate change impacts to the Corp. In addition, adherence to protective building codes for new development will also assist in limiting future impacts and associated vulnerabilities of the Corp to this hazard.

Future Development
The District has no plans to acquire or develop new properties or add structures to support their District objectives. Further, the Corp noted that it has no control over future development within its District boundaries. Responsibility for growth and development within District boundaries resides with the County and City of Portola. However, it should be noted that climate change can influence future development in the Corp over time. The District could see population fluctuations as a result of climate impacts relative to those experienced in other regions, and these fluctuations are expected to impact demand for housing and other development. While there are currently no formal studies of specific migration patterns expected to impact the Corp, climate-induced migration was recognized within the UNFCCC Conference of Parties Paris Agreement of 2015 and is expected to be the focus of future studies.

Drought & Water Shortage
Likelihood of Future Occurrence–Likely
Vulnerability–Medium
Hazard Profile
Drought and water shortage are complex issues involving many factors—it occurs when a normal amount of precipitation and snow is not available to satisfy an area’s usual water-consuming activities. Drought can often be defined regionally based on its effects. Drought is different than many of the other natural hazards in that it is not a distinct event and usually has a slow onset. Drought can severely impact a region

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Plumas County PC Annex F-23
Local Hazard Mitigation Plan Update
January 2026
both physically and economically. Drought affects different sectors in different ways and with varying intensities. Adequate water supply is the most significant issue and is critical for agriculture, manufacturing, tourism, recreation, and commercial and domestic use. Drought has also affected tree mortality in the area in the past. As the population in the area continues to grow, so will the demand for water.

Tree Mortality and Drought
One of the secondary hazards of drought in the Plumas County Planning Area, that can also affect Plumas Corp, is the increased risk to trees from beetle kill and other insects, pathogens and parasites, and other tree mortality and die back issues. Drought weakens trees and makes them more susceptible to insect infestation and other pathogens. Insects, such as bark beetles and others, frequently attack trees weakened by drought, disease, injuries, or other factors that may stress the tree. These insects and other pathogens can contribute to the decline and eventual death of trees throughout the Corp. The tree mortality and dieback problems are a high priority because of the issue of hazardous trees and an increased wildfire hazard. In addition to an increase in wildfire fuels, hazardous trees can fall onto structures causing damage and a result in a reduction on the tree canopy within the Corp that provides relief during extreme heat days.

Location and Extent
Drought and water shortage are regional phenomenon. The whole of the Corp and County is at risk. The US Drought Monitor categorizes drought conditions with the following scale:
➢ None
➢ D0 – Abnormally dry
➢ D1 – Moderate Drought
➢ D2 – Severe Drought
➢ D3 – Extreme Drought
➢ D4 – Exceptional Drought
Drought has a slow speed of onset and a variable duration. Drought can last for a short period of time (which does not usually affect water shortages) or for longer periods (which may challenge water supplies).

Should a drought last for a long period of time, water shortage becomes a larger issue.

The Plumas County Planning Area, including the Corp, has been in and out of drought since 2014. Over the last six years since the 2019 LHMP, drought conditions have ranged from none to exceptional. Drought conditions are expected to continue to be cyclical in nature depending on the year. Current drought conditions in the Corp are shown in Section 4.3.9 of the Base Plan.

Past Occurrences
Disaster Declaration History
There have been 2 state and 1 federal disaster declarations for Plumas County. This can be seen in Table F-4. Additionally, there have been 16 USDA Secretarial Disaster Declarations from drought in the County since 2012.

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Plumas County PC Annex F-24
Local Hazard Mitigation Plan Update
January 2026
Table F-4 Plumas County –State and Federal Drought Disaster Declarations 1950-2025 Disaster Type State Declarations Federal Declarations
Count Years Count Years
Drought 2 1976, 2015 1 1977
Source: Cal OES, FEMA
NCDC Events
There have been 2 NCDC drought events in Plumas County since 1993. These most likely had some impact on the Corp.

Plumas Corp Events
Based on historical information, the occurrence of drought in California, including the Plumas Corp, is cyclical, driven by weather patterns. Section 4.3.9 of the Base Plan notes that five droughts have occurred in the past 86 years that likely affected the Corp. Drought has occurred in the past and will occur in the future.

Recently, between 2020 and 2023 Plumas County experienced drought conditions that ranged from abnormally dry to extreme drought conditions with some areas experiencing exceptional drought conditions. These drought conditions exacerbated wildfire risk and were a major contributing factor to the destructive nature of the North Complex in 2020 as well as the Beckwourth Complex and Dixie Fire in 2021 (see discussions in the Wildfire hazard below). Fuels on the ground were tinder dry much earlier in the fire season than normal, and fuel moistures remained low longer into the fall months causing the fire season to begin much earlier and run longer with no true break in fire season from one year to the next.

This drought period had a significant impact on overall forest health. Many trees succumbed to the lack of moisture and tree mortality increased. Bark beetle populations expanded during this time as well due to the trees inability to produce enough pitch to defend themselves from beetle infestation. This was another contributing factor to expanding tree mortality across the county. This mortality contributes to the fuel loading of the forest as well as creating areas with significant vertical continuity to wildland fuels which create added challenges for suppression activities.

Climate Change and Drought and Water Shortage
It is likely that climate change will increase the chance of future occurrence as well as future impacts associated with drought and water shortage. More information on future impacts to the Corp can be found in the Future Conditions/Future Development section of the Vulnerability Assessment below.

Climate scientists studying California find that drought conditions are likely to become more frequent and persistent over the 21st century due to climate change. The experiences of California during recent years underscore the need to examine more closely the state’s water storage, distribution, management, conservation, and use policies. The 2021 CAS (as well as the 2024 Draft CAS) stresses the need for public policy development addressing long term climate change impacts on water supplies. The CAS notes that climate change is likely to significantly diminish California’s future water supply, stating that: California

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Plumas County PC Annex F-25
Local Hazard Mitigation Plan Update
January 2026
must change its water management and uses because climate change will likely create greater competition for limited water supplies needed by the environment, agriculture, and cities.

A 2018 report from the Public Policy Institute of California noted that thousands of Californians – mostly in rural, small, disadvantaged communities – already face acute water scarcity, contaminated groundwater, or complete water loss. Climate change would make these effects worse.

Cal Adapt scenarios for modeled future drought scenarios were shown in Section 4.3.9 of the Base Plan.

Vulnerability to Drought and Water Shortage
Based on historical information, the occurrence of drought and water shortage in California, including the Corp, is cyclical, driven by weather patterns. Drought has occurred in the past and will occur in the future.

Periods of actual drought with adverse impacts can vary in duration, and the period between droughts can be extended. Although an area may be under an extended dry period, determining when it becomes a drought is based on impacts to individual water users. The vulnerability of the Plumas Corp to drought may vary and include reduction in water supply, impacts to natural resources, and an increase in dry fuels and tree dieback.

The whole of the Corp is at some measure of vulnerability to drought and water shortage. An assessment of a community’s vulnerability to drought and water shortage begins with an understanding of local exposure to drought. This is included in the Local Concerns section below followed by a discussion of the Corp’s Assets at Risk to this hazard.

As mentioned above, drought conditions elevate wildfire risks and add to the destructive nature of the fires in this area. Suppression efforts become more challenging due to the increased fire activity and more complex tactics required for firefighters to safely engage. Fuels reduction operations are also affected by drought due to the elevated project activity levels (PAL) on federal lands which limit operations in the forest based on environmental conditions such as temperature, winds, relative humidity, and fuel moisture.

PALs are a metric used to limit operations in the forest based on environmental conditions such as temperature, winds, relative humidity, and fuel moisture. These PALs can have an impact on the operations and productivity of the Plumas County Firesafe Council’s Hazardous Fuels Reduction program which implements projects on private and public lands, which in turn, can limit the benefits of fuels reduction measures in the Plumas County Planning Area, including Plumas Corp.

The District noted that other local concerns include: domestic well failures, extremely low fuel moisture leading to extreme fire behavior, shortage of agricultural and environmental water, and accelerated tree mortality.

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Plumas County PC Annex F-26
Local Hazard Mitigation Plan Update
January 2026
Assets at Risk
Assets at risk from this hazard include people and populations; structures and critical facilities and infrastructure; and natural, historic, and cultural resources. These are discussed in the following sections.

People and Populations
The people and populations (both District staff and those located within District boundaries) are not directly affected by general drought conditions; although, their turfed areas, trees, and other water-depending resources can all be affected. In extreme drought conditions, however, residents and other populations within the Corp may be vulnerable to drought and water shortage issues. Water quality can be impacted causing health problems, especially to vulnerable populations where access to clean water supplies can be more challenging. Water shortages can have an effect on all of the populations in the Corp, but often have a greater effect on the unhoused and other vulnerable populations that may be unable to access and afford clean drinking water during shortages. During periods of drought as the costs of water usage may increase, those who are economically disadvantaged may be unable to afford the increased costs of potable water.

Structures and Critical Facilities and Infrastructure
Most structures, critical facilities, and infrastructure located within District boundaries have a limited vulnerability to drought and water shortage. Should drought conditions be severe enough to cause water shortage reliability issues, some facilities and infrastructure may be affected. Water and wastewater systems) may be impacted during times of reduced water supply and need to employ contingencies to remain functional and fully operational. Other water dependent systems may also be adversely affected.

Further, the secondary hazard of drought (increased potential for tree mortality and spread of urban fires and wildfire) can pose a significant risk to structures located within the Corp. Drought can also stress trees, causing die off. These trees may fall on critical infrastructure adjacent to them and impact power lines and other utilities. Also as previously mentioned, with the exception of their one office building, the Corp does not have other owned assets or structures that would be vulnerable to this hazard.

According to Table F-2, the Corp’s one owned facility is not at direct risk from drought and water shortage.

This District noted that drought does exacerbate wildfire. As such, their facility is at risk from drought induced wildfires.

Natural, Historic, and Cultural Resources
Drought and water shortage can have a significant impact on natural resources. Water levels in reservoirs and lakes may be reduced and a loss of wetlands and marsh areas may occur. Severe drought conditions can contribute to an increase in erosion of soils and lead to poor soil quality. Further, all of the trees and forested areasin the Corp are at risk to drought impacts and a reduction in water supply. Drought conditions also stress trees leading to higher tree mortality. These trees provide a wealth of social and environmental benefits to District residents and visitors, from shade and beauty to air quality, carbon reduction and stormwater management. Drought can devastate crops and dry out pastures, dry out forests and critical habitat areas, and reduce food and water available for wildlife and livestock. Additionally, drought conditions can also cause soil to compact and not absorb water well, potentially making an area more

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Plumas County PC Annex F-27
Local Hazard Mitigation Plan Update
January 2026
susceptible to flooding. It is unlikely that drought and water shortage would have a significant impact on historic and cultural resources in the Corp.

Impacts from Drought and Water Shortage
The vulnerability of the Corp to drought is District-wide, but impacts may vary and include reduction in water supply and an increase in dry fuels. The potential for a reduction in water supply during drought conditions generally leads to both mandated and voluntary conservations measures during extended droughts. During these times, the costs of water can also increase. Also of concern, the increased dry fuels, fuel loads, and tree mortality events associated with drought conditions can result in an increased fire danger. In areas of extremely dry fuels, the intensity and speed of fires can be significant. Water supply and flows for fire suppression can also be an issue during extended droughts. Drought can also lead to turf losses and cause tree die off within the Corp.

Other qualitative impacts associated with drought in the Corp are those related to water intensive activities such as municipal usage, commerce, tourism, and recreation use. With more precipitation likely falling as rain instead of snow in the Sierra’s, and warmer temperatures causing decreased snowfall to melt faster and earlier, water supply is likely to become more unreliable. In addition, drought and water shortage is predicted to become more common. This means less water available for use over the long run, and additional challenges for water supply reliability, especially during periods of extended drought.

Impacts to identified assets at risk to this hazard and the overall vulnerability of the Corp may be affected in the future by climate change (which was discussed in the hazard profile discussion above), changes in population patterns (migration, density, or the makeup of socially vulnerable populations), and changes in land use and development. These are discussed below.

Future Conditions
Future conditions may be affected by climate change, changes in population patterns (migration, density, or the makeup of socially vulnerable populations), and changes in land use and development. Findings on this for the Plumas Corp include the following:
➢ Climate change is likely to exacerbate future drought conditions and associated impacts and vulnerability of the Corp to drought and water shortage. ➢ Population projections within the jurisdictional boundaries of the Corp show the population to be slightly declining. It is unknown how population patterns and demographics will change in the near future. The District may add staff, but this number would be small. The District noted that it has no control over population changes within its jurisdictional boundaries. With no notable changes in populations numbers and makeup, the vulnerability of the Corp to this hazard is unlikely to change. ➢ Changes in land use and development within Plumas Corp are expected to be limited in the near future and thus are not likely to affect the vulnerability of Plumas Corp to drought and water shortage. In

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Plumas County PC Annex F-28
Local Hazard Mitigation Plan Update
January 2026
addition, adherence to protective building codes and requirements for ensuring a reliable water supply for new development will also assist in limiting future impacts and associated vulnerabilities of Plumas Corp to this hazard.

Flood: 1%/0.2% Annual Chance (w/Levee Failure)
Likelihood of Future Occurrence–Occasional (1%)/Unlikely (0.2%) Vulnerability–High
Hazard Profile
This hazard analyzes the FEMA DFIRM 1% and 0.2% annual chance floods. These tend to be the larger floods that can occur in the Corp and have caused damage in the past. Flooding can be a significant problem throughout the County and the Corp. Historically, the Corp has been at risk to flooding primarily during the winter and spring months when river systems in the Corp swell with heavy rainfall and snowmelt runoff.

The District has also been at risk during atmospheric river flood events. Normally, storm floodwaters are kept within defined limits by a variety of storm drainage and flood control measures (like levees) located throughout the Plumas County Planning Area and the Plumas Corp. Occasionally, extended heavy rains result in floodwaters that exceed normal high-water boundaries and cause damage. Flooding has occurred both within the 1% and 0.2% annual chance floodplains and in other localized areas in the Corp. The potential for levee failure flooding is also an issue in the Corp. Since the Corp’s boundaries mirror the County, levee failure is not discussed in detail in the sections below. More information on levee failure flooding can be found in Section 4.3.12 of the Base Plan.

Location and Extent
The Plumas Corp has areas located in the 1% and 0.2% annual chance flood zones. This is seen in Figure F-2.

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Plumas County PC Annex F-29
Local Hazard Mitigation Plan Update
January 2026
Figure F-2 Plumas Corp – FEMA DFIRM Flood Zones
Table F-5 details the DFIRM mapped flood zones located within the Corp.

Table F-5 Plumas Corp– DFIRM Flood Hazard Zones
Flood Zone Description Present in District
A 1% annual chance flooding: No base flood elevations provided X AE 1% annual chance flooding: Base flood elevations provided X AE Regulatory Floodway 1% annual chance flood: Regulatory floodway; Base flood elevations provided
X
AH 1% annual chance flood areas of shallow flooding between one to three feet deep. Regulatory floodway; Base flood elevations provided
X
Shaded X 0.2% annual chance flooding: The areas between the limits of the 1% annual chance flood and the 0.2-percent-annual-chance (or 500-year) flood
X
X (unshaded) Area of minimal flood hazard X
Source: FEMA DFIRM 03/02/2005

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Plumas County PC Annex F-30
Local Hazard Mitigation Plan Update
January 2026
Additionally, flood extents can generally be measured in volume, velocity, and depths of flooding.

Expected flood depths in the Corp vary, depending on the nature and extent of a flood event; specific depths are unknown. Flood durations in the Corp tend to be short to medium term, until either the storm drainage system can catch up or flood waters move downstream. Flooding in the Corp tends to have a shorter speed of onset, due to the amount of water that flows through the Corp.

Geographical flood extents for the Corp from the FEMA DFIRMs are shown in Table F-6.

Table F-6 Plumas Corp – Geographical DFIRM Flood Zone Extents by Jurisdiction Jurisdiction /
Flood Zone
Total Acres % of Total
Acres
Improved
Acres
% of Total
Improved
Acres
Unimproved
Acres
% of Total
Unimproved
Acres
City of Portola
1% Annual
Chance Flood
Hazard
168 0.01% 10 0.01% 157 0.01%

0.2% Annual
Chance Flood
Hazard
1 0.0001% 0.1 0.0001% 0.7 0.00005%
Other Areas 3,323 0.2% 2,227 2.4% 1,096 0.1%
City of Portola
Total
3,491 0.2% 2,237 2.4% 1,254 0.1%
Unincorporated Plumas County
1% Annual
Chance Flood
Hazard
84,609 5.1% 23,036 24.8% 61,573 3.9%

0.2% Annual
Chance Flood
Hazard
1,431 0.1% 667 0.7% 764 0.05%
Other Areas 1,582,631 94.6% 67,072 72.1% 1,515,559 96.0% Unincorporated
Plumas County
Total
1,668,671 99.8% 90,775 97.6% 1,577,896 99.9%
Grand Total 1,672,162 100.0% 93,013 100.0% 1,579,150 100.0% Source: FEMA DFIRM 03/02/2005
Past Occurrences
Disaster Declaration History
A list of state and federal disaster declarations for Plumas County from flooding is shown on Table F-7.

These events also likely affected the Corp to some degree.

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Plumas County PC Annex F-31
Local Hazard Mitigation Plan Update
January 2026
Table F-7 Plumas County – State and Federal Disaster Declarations from Flood 1950-2025 Disaster Type State Declarations Federal Declarations
Count Years Count Years
Flood (including heavy
rain and storm)
22 1950, 1955, 1958 (twice), 1964,
1963, 1964, 1969, 1970 1980,
1986, 1993, 1992*, 1995
(twice*), 1996, 1997, 2006, 2017
(twice*), 2023 (twice*)
19 1950, 1955, 1958 (twice), 1963,
1964, 1969, 1970, 1986, 1992
(twice), 1995 (twice), 1997,
2006*, 2017 (twice*), 2023
(twice*)
Source: Cal OES, FEMA
*included a landslide component
NCDC Events
The NCDC tracks flooding events for the County. Events have been tracked for flooding since 1993.

Plumas County has seen 15 events. Depending on the location, these events most likely had some impact on the Corp.

Plumas Corp Events
The District noted that the following events had affects or damages to the Corp:
2017 Flood – long duration rain event with high antecedent moisture. Solidly between the ’86 & ’97 floods in stage and volume. Feather River Cyn Hwy 70 & railroad severely damaged for 3rd time. 1997 Flood – long duration rain on snow event with high antecedent moisture. Currently stands as flood of record on Indian Creek since 1906 (42,000- 44,000 cfs). Despite higher flows, there was less local infrastructure damage. Feather River Cyn Hwy 70 & railroad severely damaged again. 1986 Flood – long duration high intensity rain on snow. Flood of record (36,200 cfs) on Indian Creek at that time. Extensive damage to county road and bridges, Hwy 70 in Feather River Cyn and Union Pacific railroad line severely damaged.
1955 Flood – anecdotal accounts speak of profound changes in the condition of many stream channels throughout the Corp. Many of the original county bridges were lost. Deleterious effects of some post-flood channel repairs and “modifications” still persist.

Other NCDC flood events – events from the early 1960’s and 1990’s were similar to the 1955 flood in magnitude (±25,000 cfs at Arlington Bridge), but far less in effects. Effects would be more localized.

Indian Creek at the exit from Indian Valley was gaged by the USGS from 1906 to 1993, with notable later events back-calculated by USGS or Plumas Corp. It serves as a magnitude surrogate for discussions here.

Discharge volume in the 1986 was 30% greater than any previous flood in the period of record. 1997 was 15% greater than 1986, with the 2017 flood volume solidly in between.

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Plumas County PC Annex F-32
Local Hazard Mitigation Plan Update
January 2026
Climate Change and Flood
It is likely that climate change will increase the chance of future occurrence as well as future impacts associated with flood. More information on future impacts to the Corp can be found in the Future Conditions/Future Development section of the Vulnerability Assessment below.

According to the 2021 CAS (as well as the 2024 Draft CAS), climate change may affect flooding in California, the Plumas County Planning Area, and the Plumas Corp. While average annual rainfall may increase or decrease slightly, the intensity of individual rainfall events is likely to increase during the 21st century. It is possible that average soil moisture and runoff could decline, however, due to increasing temperature, evapotranspiration rates, and spacing between rainfall events. Reduced snowpack and increased number of intense rainfall events are likely to put additional pressure on water infrastructure which could increase the chance of flooding associated with breaches or failures of flood control structures such as levees and dams. Cal Adapt future precipitation projections were shown in Section 4.3.4.

Vulnerability to Flood: 1% and 0.2% Annual Chance
Floods have been a part of the Corp’s historical past and will continue to be so in the future. During winter months, long periods of precipitation and the timing of that precipitation are critical in determining the threat of flood, and these characteristics further dictate the potential for widespread structural and property damage. Predominantly, the effects of 1% and 0.2% annual chance flooding are generally confined to areas near the waterways of the Corp. As waterways grow in size from local drainages, so grows the threat of flood and dimensions of the threat.

The whole of the Corp is at some measure of vulnerability to floods. An assessment of a community’s vulnerability to flood begins with an understanding of local exposure to flood. This is included in the Local Concerns section below followed by a discussion of the Corp’s Assets at Risk to this hazard.

The principal large flood hazard water bodies are Middle Fork Feather River (Sierra Valley/Portola), Spanish Creek (Quincy area), Indian Creek (Indian Valley/Genesee) and North Fork Feather River (Chester/Canyon).

Generalized flooding of communities has not been a significant issue in the Corp, historically. Of more concern is community isolation due to flooded roads, washed out bridges/culverts and/or debris blockages.

Again, using Indian Valley/Indian Creek as examples: at 10,000 cfs North Valley Road (Cassity Corner) and the west bridge on Stampfli Lane are flooded, folks south of those points can still exit via Arlington Bridge; at 25,000 cfs Arlington Bridge is overtopped, as is Deadfall Bridge, leaving Taylorsville, North Arm and Genesee isolated from medical and other services; at the same stage Genesee Road at Rocky Point floods isolating Genesee from Taylorsville, Ward Creek Road floods isolating residents on the south side of Genesee Valley. Similar scenarios occur in each of the principal inhabited valleys in the Corp. The 204

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Plumas County PC Annex F-33
Local Hazard Mitigation Plan Update
January 2026
square mile Last Chance Creek watershed is one of two large sub watersheds to Indian Creek. Indian Creek flows through Genesee and Indian valleys where flooding and channel instability are current hazards to the populace.

The Last Chance Creek watershed contains one of the longest contiguous meadow floodplain systems in the Sierra Nevada Mountains. Last Chance Creek is severely down cut (incised) throughout the 36 miles of meadow floodplain. Principal stressors were logging railroad grades built in the low gradient meadow in the 1930s & ‘40s, channel modification, livestock grazing, and roads. These incised channels funnel all flows downstream, rapidly draining out this headwater basin into the populated Genesee and Indian valleys.

Loss of floodplain function and the rapid drainage of these headwater basins reduces the meadow’s ability to capture and store springtime snowmelt and rain as shallow groundwater. Sixty percent of California’s water supply originates in the Sierra Nevada, and meadows are a key component of that supply, helping to regulate water flow, temperature, and quality. As the headwaters of the State Water Project, the Feather River Watershed provides water to over 26 million Californians. Although wet meadows are less than one percent of the overall landscape in Plumas County, meadows’ unique hydrologic and ecological functions are recognized as being vital to watershed health and are valued for the ecosystem goods and services they provide, such as crucial habitat for many endemic and special status wildlife species. Known as biological diversity hot spots, healthy meadows provide refugia for wildlife during droughts and wildfire. Wet and moist meadows sequester carbon in the soil, where it isn’t susceptible to being lost in a wildfire. In addition, functioning meadow floodplains provide natural fire breaks reducing fire intensities and rate of spread.

Over 6,000 acres of meadow surface are available for flood attenuation along Last Chance and its tributaries. From 1995 to 2007, 9 miles and 800 acres of floodplain has been restored by Plumas Corporation. The work restored the hydraulic base level of Last Chance and tributaries back to the historic meadow level, recovering crucial floodplain function. The larger Last Chance Creek project was originally divided into Phase 1, Phase 2, and Phase 3. Phase 1 is primarily complete representing the abovementioned accomplishments. Phase 2 has been designed; funds to complete NEPA/CEQA, permits and implementation are needed. Phase 3 awaits planning funds.

The District is also concerned with rain on snow events, which can cause greater flooding in the Corp. Loss of headwater floodplains accelerates the movement of floodwaters originating from rain-on-snow events.

Such events are expected to occur with more frequency with climate change.

People and Populations
All people and populations (both District staff and those located within District boundaries) located in the 1% and 0.2% annual chance floodplains are at some risk to flooding. Certain vulnerable populations located within areas prone to flooding may be at increased risk to this hazard, especially during a large event with minimal advance notice. These vulnerable populations include: the unhoused, those with limited mobility, and those that lack the resources to leave the area.

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Plumas County PC Annex F-34
Local Hazard Mitigation Plan Update
January 2026
Not only are populations at risk, but their homes and contents can all be at risk, compounding the impacts associated with significant flood events.

Structures and Critical Facilities
As previously mentioned, with the exception of their one office building, the Corp does not have other owned assets or structures. The Plumas Corp office building is not at risk to the 1%/0.2% annual chance flood as detailed in Table F-2. However, those structures within the Corp boundaries that fall within the 1% and 0.2% annual chance floodplains would be at risk.

Flooding presents a threat to both critical facilities and infrastructure, as well as community lifelines.

Critical infrastructure plays an immensely important role in our communities. As previously noted, communities rely on roads, rail corridors, and related biking and pedestrian routes for transportation, and on water infrastructure for drinking water, wastewater service, and draining streets of rainwater. Damage to any one of these systems can threaten public safety, wreak havoc on daily life, impact properties far from flood zones, and result in economic impacts that cascade throughout California.

Natural, Historic, and Cultural Resources
Large flood events can affect natural, historic, and cultural resources. There are a number of ways floodwaters can impact natural resources and the environment. Wildlife habitats can be destroyed by floodwaters. Contaminated floodwater can pollute rivers and habitats. Silt and sediment can destroy natural areas. Riverbanks and natural levees can be eliminated as rivers reach bankfull capacity. Rivers can be widened, and deposition can increase downstream. Trees can be uprooted by high-velocity water flow.

Plants that survive the initial flood may die due to being inundated with water. Historic and cultural resources may also be affected. Generally, the impacts are associated with damage to structures within the flooded areas, but other cultural resources such as those associated with Native Americans and old tribal areas can also be disturbed, damaged and lost during extreme flood events. Any of these that fall in the flood zones shown on Figure F-2 would be vulnerable.

Impacts from Flood: 1% and 0.2% Annual Chance
Floods are among the costliest natural disasters in terms of human hardship and economic loss nationwide.

Large flood events, including those associated with 1% and 0.2% annual chance floods, can cause substantial damage to structures, landscapes, and utilities as well as life safety issues. People may be swept away in floodwaters, causing injuries or deaths. Floods can be extremely dangerous, and even six inches of moving water can knock over a person given a strong current. During a flood, people can also suffer heart attacks or electrocution due to electrical equipment short outs. Direct impacts, such as drowning, can be limited with adequate warning and public education about what to do during floods. Floodwaters can transport large objects downstream which can damage or remove stationary structures. Structures can be damaged directly from floodwaters and can also be damaged from trees falling as a result of water-saturated soils. Ground saturation can result in instability, collapse, or other damage. Objects can also be buried or destroyed through sediment deposition. Floodwaters can also break utility lines and interrupt services causing power outages. The interruption of power causes major problems and can result in the closure of

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Plumas County PC Annex F-35
Local Hazard Mitigation Plan Update
January 2026
governmental offices and community businesses. Roads can be damaged and closed, causing safety and evacuation issues.

Standing water can cause damage to crops, roads, foundations, and electrical circuits. Other problems connected with flooding and stormwater runoff include erosion, sedimentation, degradation of water quality, loss of environmental resources, and economic impacts.

Impacts to identified assets at risk to this hazard and the overall vulnerability of the Corp may be affected in the future by climate change (which was discussed in the hazard profile discussion above), changes in population patterns (migration, density, or the makeup of socially vulnerable populations), and changes in land use and development. These are discussed below.

Future Conditions
Future conditions may be affected by climate change, changes in population patterns (migration, density, or the makeup of socially vulnerable populations), and changes in land use and development. Findings on this for the Plumas Corp include the following:
➢ As discussed in the hazard profile section, climate change is anticipated to exacerbate this hazard over time.
➢ Population projections within the jurisdictional boundaries of the Corp show the population to be slightly declining. It is unknown how population patterns and demographics will change in the near future. The District may add staff, but this number would be small. The District noted that it has no control over population changes within its jurisdictional boundaries. With no notable changes in populations numbers and makeup, the vulnerability of the Corp to this hazard is unlikely to change. ➢ Changes in land use and development in the Corp are expected to be limited in the near future and thus are not likely to affect flooding and associated impacts to the Corp. Additional development traditionally leads to additional flooding. In addition, adherence to protective building codes for new development will assist in limiting future impacts and associated vulnerabilities of the Corp to this hazard.

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Plumas County PC Annex F-36
Local Hazard Mitigation Plan Update
January 2026
Flood: Localized Stormwater Flooding
Likelihood of Future Occurrence–Highly Likely
Vulnerability–Medium
Hazard Profile
Flooding occurs in areas other than the FEMA mapped 1% and 0.2% annual chance floodplains. Flooding may be from drainages not studied by FEMA, lack of or inadequate drainage infrastructure, or inadequate maintenance. Localized, stormwater flooding occurs throughout the Corp and the Plumas County Planning Area, especially during the rainy season from November through April. Prolonged heavy rainfall (including that from atmospheric river events) contributes to a large volume of runoff resulting in high peak flows of moderate duration.

Location and Extent
Plumas Corp is subject to localized flooding throughout the Corp. This is discussed in the Local Concerns section below. Flood extents are usually measured in areas affected, velocity of flooding, and depths of flooding. Expected flood depths in the Corp vary by location. Flood durations in the Corp tend to be short to medium term, or until either the storm drainage system can catch up or flood waters move downstream.

Localized flooding in the Corp tends to have a shorter speed of onset, especially when antecedent rainfall has soaked the ground and reduced its capacity to absorb additional moisture.

Past Occurrences
Disaster Declaration History
There have been no state or federal disaster declarations specific to localized floods. There would most likely have been localized flood events during the 22 state and 19 federal disaster declarations for flood events, including heavy rains and storms, as shown in the previous 1%/0.2% annual chance flood section.

NCDC Events
The NCDC occurrences of localized flooding are included in the 1% and 0.2% annual chance flood hazard profile above where past flood events were noted. These include 15 flood related events for the entire County Planning Area reported since 1993.

Plumas Corp Events
Localized flooding in the Corp has generally been of a stochastic nature, from transient causes; not recurring events. Typically, localized flooding occurs with high intensity rain on saturated soils/snowmelt generating mineral and organic debris loads, temporary debris jams, beaver dams, etc., often enhanced by recent wildfire effects. This occurs yearly.

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Plumas County PC Annex F-37
Local Hazard Mitigation Plan Update
January 2026
Climate Change and Localized Flood
It is likely that climate change will increase the chance of future occurrence as well as future impacts from localized floods. Atmospheric river events, occurring in recent years, is thought to be attributed to climate change and reflect storms of greater volume and intensity. More information on future impacts to the Corp can be found in the Future Conditions/Future Development section of the Vulnerability Assessment below.

Even if average annual rainfall may decrease slightly, the intensity of individual rainfall events is likely to increase during the 21st century, increasing the likelihood of overwhelming stormwater systems built to historical rainfall and storm averages. This makes localized flooding more likely.

Vulnerability to Localized Flood
Flood vulnerability and their impacts vary by location and severity of any given flood event and will likely only affect certain areas of the Corp during specific times. Based on the risk assessment, it is evident that floods will continue to have potentially significant impacts to certain areas of the Corp. However, while flooding can cause significant impacts, depending on the duration and volume of precipitation and the drainage in any given area, many of the floods in the Corp are minor, localized flood events that are more of a nuisance than a disaster.

Many areas of the Corp are at some measure of vulnerability to localized flooding. An assessment of a community’s vulnerability to localized flooding begins with an understanding of local exposure to localized flooding. This is included in the Local Concerns section below followed by a discussion of the Corp’s Assets at Risk to this hazard.

Historically, the Corp has been affected by flooding of streams and creeks occurring during heavy rain and storm (including atmospheric river) events. Additional development in the Corp and in the watersheds of these streams affects both the frequency and duration of damaging floods through an increase in stormwater runoff and contributes to localized flooding occurring in areas throughout the Corp. The lack of, or inadequate, drainage of built infrastructure in the County Planning Area and the Corp contributes to localized flooding issues. Impervious services in the district will also exacerbate rain on snow events flooding.

Localized flooding in the Corp has generally been of a stochastic nature, from transient causes; not recurring events. Typically, localized flooding occurs with high intensity rain on saturated soils/snowmelt generating mineral and organic debris loads, temporary debris jams, beaver dams, etc., often enhanced by recent wildfire effects.

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Plumas County PC Annex F-38
Local Hazard Mitigation Plan Update
January 2026
Assets at Risk
Assets at risk from this hazard include people and populations; structures and critical facilities; and natural, historic, and cultural resources. These are discussed in the following sections.

People and Populations
All District staff and populations within District boundaries (including vulnerable populations) are traditionally not highly vulnerable to localized flooding, but their structures and contents can be at risk.

Localized flooding may also cause transportation issues as roads and lanes are impacted or closed and affect the ability for District staff and District residents to travel throughout the Corp.

The District’s only asset (as shown in Table F-2) is at risk to localized flooding. Plumas Corp owns property that is adjacent to elevated water holding ponds that are used to store run-off from the Sierra Pacific Industries mill. This water is utilized to spray log stock to minimize checking and splitting of logs prior to milling operations. During periods of heavy rainfall the ponds can reach capacity and on occasion have overflowed. Additionally, due to the earthen construction of the containment walls small breaches have been witnessed during heavy rain events. Large pumps are regularly utilized to manage water levels and mitigate overflow risks. The combined risk of overflowing and potential breaches pose a threat of flooding to Plumas Corp assets particularly due to the reliance on mechanized equipment to mitigate the hazard.

Natural, Historic, and Cultural Resources
Natural resource assets may have some vulnerabilities to localized flood during major storm events, but can benefit from floodwaters, often by design. Many open spaces take overflow water and release it into the underlying soils and natural areas. Wetlands areas in the Corp actually help reduce the risk of flooding, as they can absorb excess rainfall that would have to be drained away from impervious surfaces. Flooding can provide many benefits to the natural environment, including recharging wetlands and groundwater, increasing fish production, creating wildlife habitat, and rejuvenating soil fertility. These smaller localized flooding events often provide more benefits to the environment in comparison to negative impacts associated with large flood events. Historic and cultural resources may be at some measure of vulnerability if they are located in areas subject to repeated localized flooding.

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Plumas County PC Annex F-39
Local Hazard Mitigation Plan Update
January 2026
collapse, or other damage to trees, structures, roadways and other critical District infrastructure. Objects can also be buried or destroyed through sediment deposition. Floodwaters can break utility lines and interrupt services to District facilities. Standing water can cause damage to crops, roads, and foundations of District facilities. Other problems connected with flooding and stormwater runoff include erosion, sedimentation, degradation of water quality, losses of environmental resources, and certain health hazards.

Impacts to identified assets at risk to this hazard and the overall vulnerability of the Corp may be affected in the future by climate change (which was discussed in the Likelihood of Future Occurrence discussion above), changes in population patterns (migration, density, or the makeup of socially vulnerable populations), and changes in land use and development. These are discussed below.

Future Conditions
Future conditions may be affected by climate change, changes in population patterns (migration, density, or the makeup of socially vulnerable populations), and changes in land use and development. Findings on this for the Plumas Corp include the following:
➢ As discussed in the hazard profile section, climate change is anticipated to exacerbate this hazard over time.
➢ Population projections within the jurisdictional boundaries of the Corp show the population to be slightly declining. It is unknown how population patterns and demographics will change in the near future. The District may add staff, but this number would be small. The District noted that it has no control over population changes within its jurisdictional boundaries. With no notable changes in populations numbers and makeup, the vulnerability of the Corp to this hazard is unlikely to change. ➢ Changes in land use and development in the Corp are expected to be limited in the near future and thus are not likely to affect flooding and associated impacts to the Corp. Additional development traditionally leads to additional flooding. However, adherence to protective building codes for new development will assist in limiting future impacts and associated vulnerabilities of the Corp to this hazard.

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Plumas County PC Annex F-40
Local Hazard Mitigation Plan Update
January 2026
stormwater or choosing not to develop in areas that often are subject to localized flooding will reduce future risks of losses due to stormwater/localized flooding. Future development occurring within District boundaries will add to the drainage issues already faced by the Corp, unless adequate drainage facilities are installed in new development locations.

Severe Weather: Extreme Heat
Likelihood of Future Occurrence–Highly Likely
Vulnerability–Medium
Hazard Profile
According to FEMA, extreme heat is defined as temperatures that hover 10 degrees or more above the average high temperature for the region and lasts for several weeks. Heat kills by taxing the human body beyond its abilities. In extreme heat and high humidity, evaporation is slowed, and the body must work extra hard to maintain a normal temperature.” Most heat disorders occur because the victim has been overexposed to heat or has over-exercised for his or her age and physical condition. Older adults, young children, those who are sick or overweight, and those that work or recreate outdoors are more likely to experience heat exhaustion or succumb to extreme heat.

In addition to the risks faced by populations within the Corp, there are risks to the built environment from extreme heat. While extreme heat on its own does not usually affect structures, extreme heat during times of drought can cause wildfire risk to heighten. Extreme heat can lead to interruptions in power, power outages, and when combined with high winds, to Public Safety Power Shutdown (PSPS) events, creating significant issues in the Corp. Extreme heat can also affect air quality conditions making certain populations more vulnerable to heat related issues.

Location and Extent
According to the WRCC, in Plumas County, monthly average maximum temperatures in the warmest months (May through October) range from the low-70s to the upper-80s, with temperatures often exceeding 100° during the summer months. Extreme heat events occur on a regional basis. Extreme heat can occur in any location of the Corp. Extreme heat occurs throughout the Corp primarily during the summer months.

The NWS has in place a system to initiate alert procedures (advisories or warnings) when extreme heat is expected to have a significant impact on public safety. The expected severity of the heat determines whether advisories or warnings are issued. The NWS HeatRisk forecast provides a quick view of heat risk potential over the upcoming seven days. The heat risk is portrayed in a numeric (0-4) and color (green/yellow/orange/red/magenta) scale which is similar in approach to the Air Quality Index (AQI) or the UV Index. This can be seen in Section 4.3.3 of the Base Plan.

Past Occurrences
Disaster Declaration History
There have been no federal or state disaster declarations from extreme heat.

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Plumas County PC Annex F-41
Local Hazard Mitigation Plan Update
January 2026
NCDC Events
The NCDC data shows 7 extreme heat incidents for Plumas County since 1993, some of which likely affected the Corp.

Plumas Corp Events
The District noted that extreme heat is a yearly event. Past damages from extreme heat events could not be recalled.

Climate Change and Extreme Heat
The 2021 CAS (as well as the 2024 Draft CAS), citing a California Energy Commission study, states that “over the past 15 years, heat waves have claimed more lives in California than all other declared disaster events combined.” This study shows that California is getting warmer, leading to an increased frequency, magnitude, and duration of heat waves. These factors may lead to increased mortality from excessive heat.

As temperatures increase, California and Plumas County will face increased risk of death from dehydration, heat stroke, heat exhaustion, heart attack, stroke and respiratory distress caused by extreme heat. According to the 2021 CAS (as well as the 2024 Draft CAS) report and the 2023 State of California Hazard Mitigation Plan, by 2100, hotter temperatures are expected throughout the state, with projected increases of 3-5.5°F (under a lower emissions scenario) to 8-10.5°F (under a higher emissions scenario). These changes could lead to an increase in deaths related to extreme heat in Plumas County.

Vulnerability to Severe Weather: Extreme Heat
Extreme heat is becoming more frequent, intense, longer lasting and geographically widespread. Extreme heat occurs on an annual basis in the County and the Corp. In recent years, compounded by climate change conditions, summer months continue to get a bit hotter. The whole of the Corp is at some measure of vulnerability to extreme heat.

An assessment of a community’s vulnerability to extreme heat begins with an understanding of local exposure to extreme heat. This is included in the Local Concerns section below followed by a discussion of the Corp’s Assets at Risk to this hazard.

The District noted that extreme heat occurs every year, and that the greatest risk from this hazard is the cascading effects of dry temperatures and increased wildfire risk. Air quality is also a concern during extreme heat days. Extreme heat can also lead to power outages including PSPS events.

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Plumas County PC Annex F-42
Local Hazard Mitigation Plan Update
January 2026
Assets at Risk
Assets at risk from this hazard include people and populations; structures and critical facilities; and natural, historic, and cultural resources. These are discussed in the following sections.

People and Populations
All District staff and the populations within District boundaries are at some vulnerability to extreme heat.

Those District employees that work outdoors or inside facilities without proper cooling systems are likely to be most affected by extreme heat conditions.

Extreme heat can also affect air quality conditions making certain populations more vulnerable to heat related issues. All populations served by the Corp are vulnerable to extreme heat, but it generally affects people spending large amounts of time outside or without means of cooling indoor structures. During extended periods of high temperatures, extreme heat may overload the demands for electricity to run air conditioners and can present health concerns to individuals. When interruptions in power occur during extreme heat, the risk of heat related illnesses and deaths increase. Extreme heat is a significant concern to vulnerable populations. The unhoused; individuals who exercise or train outdoors; outdoor workers (like District staff); individuals that lack the resources to afford heat; and the young, old, or medically fragile individuals are more susceptible to heat related impacts. In addition to vulnerable populations, pets and livestock are at risk to extreme heat conditions.

Structures and Critical Facilities and Infrastructure
Extreme heat normally does not generally impact structures and critical facilities and Infrastructure, but individuals working in structures may be affected during periods of extended heat, especially in structures that might not be equipped with air conditioning or other means of cooling. The District noted that extreme heat has caused interruptions to power in the past. Also depending on the structure, sensitive contents such as IT equipment can be impacted, especially if a power outage occurs.

Plumas Corp noted that extreme heat will not directly affect its owned asset, but a wildfire that is exacerbated by extreme heat could affect the structure shown in Table F-2. A power outage or PSPS event could also limit the use of their structure until power can be restored.

Natural, Historic, and Cultural Resources
Natural resource assets, including those located in District, may be vulnerable during periods of extreme heat. These include turfed areas; landscapes, trees, wildlife and habitat areas, and wetlands and marsh lands. Recently, trees were lost in areas of the Corp that were weakened by drought and extreme heat.

Extreme heat may also cause drought-like conditions, contributing to other issues. For example, several weeks of extreme heat increases evapotranspiration and reduces moisture content in vegetation, leading to higher wildfire vulnerability in the region for that time period, even if the rest of the season is relatively moist. Historic and cultural resources are not expected to be affected by extreme heat.

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Plumas County PC Annex F-43
Local Hazard Mitigation Plan Update
January 2026
Impacts from Severe Weather: Extreme Heat
The District experiences temperatures in excess of 100°F during the summer and fall months. The temperature moves to 105-110°F in rather extreme situations. During these times, drought conditions may worsen, and the Corp may see an increase in dry fuels contributing to the wildfire hazard. Extreme heat can damage agricultural assets in the Corp service territory. Also, power outage and PSPS events may occur during these times as well. Health issues are a primary concern with this hazard, especially to vulnerable populations, although economic impacts can also be an issue.

Future Conditions
Future conditions may be affected by climate change, changes in population patterns (migration, density, or the makeup of socially vulnerable populations), and changes in land use and development. Findings on this for District include the following:
➢ As discussed in the hazard profile section, climate change is anticipated to exacerbate this hazard over time.
➢ Population projections within the jurisdictional boundaries of the Corp show the population to be slightly declining. It is unknown how population patterns and demographics will change in the near future. The District may add staff, but this number would be small. The District noted that it has no control over population changes within its jurisdictional boundaries. With no notable changes in populations numbers and makeup, the vulnerability of the Corp to this hazard is unlikely to change. ➢ Changes in land use and development in the Corp are expected to be limited in the near future and thus are not likely to affect heat and associated impacts to the Corp. Adherence to protective building codes for new development will also assist in limiting future impacts and associated vulnerabilities of the Corp to this hazard.

Additionally, implementing energy efficiency and conservation efforts should be undertaken to reduce stress on electricity systems during heat waves.

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Plumas County PC Annex F-44
Local Hazard Mitigation Plan Update
January 2026
Severe Weather: Heavy Rains and Storms
Likelihood of Future Occurrence–Highly Likely
Vulnerability–Medium
Hazard Profile
Storms in the Corp occur annually and are generally characterized by heavy rain often accompanied by strong winds and sometimes lightning and hail. Approximately 10 percent of the thunderstorms that occur each year in the United States are classified as severe. A thunderstorm is classified as severe when it contains one or more of the following phenomena: hail that is three-quarters of an inch or greater, winds in excess of 50 knots (57.5 mph), or a tornado. Heavy precipitation in the Corp falls mainly in the fall, winter, and spring months. It can come normally, or as part of an atmospheric river event. Those events were discussed in Section 4.3.4 of the Base Plan. Wind often accompanies these storms; hail and lightning are rare in the Corp. Rain coming during times of snow are of particular concern to the Corp, as even smaller rains can melt snow, causing flooding issues.

Location and Extent
Heavy rains in Plumas County vary by season and location. Plumas County is located in the Northern portion of the Sierra Nevada region and has significant topographic variation, which causes it to experience a more severe and geographically variable winter climate (discussed in more detail in Section 4.3.2 of the Base Plan). The highest precipitation amounts are seen in the Western portion of the county where there is an orographic lift that forces air from low elevations to a higher elevation, quickly cooling down the air and raising the relative humidity to 100%. Under the right conditions orographic lifts create rain shadows where high amounts of precipitation are found on the crests of mountain ranges, but as the air descends to the leeward side of the mountain it warms and dries. In Plumas County the leeward side of the mountains represents the Eastern portion of the county where precipitation typically averages around two inches in the wettest months of the year.

Rains and storms can occur in any location of the Corp. All portions of the Corp are at risk to heavy rains and storms. Most of the severe rains occur during the fall, winter, and spring months in the Corp as discussed below (with problem flooding areas associated with heavy rains and storms discussed in the Flood: Localized Stormwater section). There is no scale by which heavy rains and severe storms are measured. Magnitude of storms is measured often in rainfall and damages. The speed of onset of heavy rains can be short, but accurate weather prediction mechanisms often let the public know of upcoming events. Hail and lightning are rarer in the Corp and Plumas County. Duration of severe storms in the Corp can range from minutes to hours to days.

Past Occurrences
Disaster Declaration History
According to historical hazard data, severe weather, including heavy rains and storms, is an annual occurrence in the Corp. This contributes to many of the federal disaster declarations related to flooding.

Disaster declarations from flooding, including heavy rains and storms, are shown on Table F-8. In addition,

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Plumas County PC Annex F-45
Local Hazard Mitigation Plan Update
January 2026
there have been two USDA disaster declarations from heavy rain and storms (once in 2016 and once in 2017) since 2012.

Table F-8 Plumas County – State and Federal Disaster Declarations from Flood (Heavy Rain and Storms) 1950-2025
Disaster Type State Declarations Federal Declarations
Count Years Count Years
Flood (including heavy
rains and storms)
22 1950, 1955, 1958 (twice), 1964,
1963, 1964, 1969, 1970 1980,
1986, 1993, 1992*, 1995
(twice*), 1996, 1997, 2006, 2017
(twice*), 2023 (twice*)
19 1950, 1955, 1958 (twice), 1963,
1964, 1969, 1970, 1986, 1992
(twice), 1995 (twice), 1997,
2006*, 2017 (twice*), 2023
(twice*)
Source: Cal OES, FEMA
NCDC Events
The NCDC data recorded 132 hail, heavy rain, and storm incidents for Plumas County since 1950.

Plumas Corp Events
The District noted that heavy rains and storms are an annual occurrence often resulting in flooding. Events causing flood issues are listed in the Past Occurrences section of the Flood: 1%/0.2% Annual Chance and Flood: Localized Stormwater Flooding discussions above.

Climate Change and Heavy Rains and Storms
It is likely that climate change will increase the chance of future occurrence as well as future impacts from heavy rains and storms. More information on future impacts to the Corp can be found in the Future Conditions/Future Development section of the Vulnerability Assessment below.

It is unlikely that hail will become more common in Plumas County and Plumas Corp. The amount of lightning is not projected to change.

Vulnerability to Heavy Rain and Storms
Heavy rain and severe storms are the most frequent type of severe weather occurrences in the Corp. These events can cause both significant and localized flooding. Flooding can be worse during times where the ground is already saturated. Wind often accompanies these storms and has caused damage in the past. Hail and lightning are rare in the Corp, but also can cause damage, with lightning occasionally igniting wildfires.

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Plumas County PC Annex F-46
Local Hazard Mitigation Plan Update
January 2026
The whole of the Corp is at some measure of vulnerability to heavy rain and storms. An assessment of a community’s vulnerability to heavy rains and storms begins with an understanding of local exposure to heavy rain and storms. This is included in the Local Concerns section below followed by a discussion of the Corp’s Assets at Risk to this hazard.

The District noted that one of the primary issues associated with heavy rains and storms is the resulting flooding caused by large precipitation events. Heavy rains and storms have a significant relationship with flooding risks, as well as, impacting water quality and agricultural infrastructure. The District is also concerned with rain on snow events, which can cause greater flooding in the Corp. Specific waterbodies, locations, event magnitudes and damages have been discussed under Vulnerability to Flood: 1% and 0.2% Annual Chance.

Also of concern to the Plumas Corp, heavy rain and storms can, overtime, contribute to the wildfire hazard within the County and the Plumas Corp. Rain impacts fuels differently based on the size and duration of rainfall events. Initially rain increases fuel moisture content which can decrease a fuel’s flammability and fire intensity and behavior, reducing an area’s fire risk. However, consistent or high annual rainfall can contribute to increased vegetation growth which can lead to higher fuel loading in an area, that without some fuels management or fuels reduction treatments, can increase the wildfire hazard in the County Planning Area and the Plumas Corp. Lightning that occurs with or outside of these storms can also cause ignitions in the County and the Corp. Any ignition, especially those occurring in remote areas of the County can become an out of control wildfire.

People and Populations
All District staff and the populations within District boundaries are at some vulnerability to heavy rains and storms. Those District employees that work outdoors could be affected to a limited extent by this hazard.

All populations served by the Corp have some measure of risk to heavy rains and storms. Those populations that work or recreate outside and unhoused individuals are more vulnerable to impacts from heavy storm events. Heavy rains and storms occur every year and do not generally cause significant adverse impacts to individuals; it is the secondary hazard, flooding, which poses the biggest impact to people.

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Plumas County PC Annex F-47
Local Hazard Mitigation Plan Update
January 2026
to withstand heavy rains and storms (including thunderstorm winds and lightning); older structures may be more vulnerable. During a heavy storm, localized flooding may cause water intrusion into buildings from the outside. Trees can be downed causing impacts to structures. Older homes and buildings may be at increased risk to heavy rains and storms. Power outages during severe storm events can occur, impacting the use of structures until the power is back online. Local roads, streets, and bridges can be impacted resulting in closures restricting traffic flow in the Corp. In certain areas, large storms can cause erosion and localized landslides which can impact affected facilities.

The Plumas Corp noted that heavy rains may bring on floods that can affect the Corp’s one asset identified in Table F-2.

Lightning can also cause wildfires and urban fires to occur. Landsliding and erosion occur when the soil on slopes becomes oversaturated and fails. Climate change may cause these impacts to worsen.

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Plumas County PC Annex F-48
Local Hazard Mitigation Plan Update
January 2026
Future Conditions
Future conditions may be affected by climate change, changes in population patterns (migration, density, or the makeup of socially vulnerable populations), and changes in land use and development. Findings on this for the Corp include the following:
➢ As discussed in the hazard profile section, climate change is anticipated to exacerbate this hazard over time.
➢ Population projections within the jurisdictional boundaries of the Corp show the population to be slightly declining. It is unknown how population patterns and demographics will change in the near future. The District may add staff, but this number would be small. The District noted that it has no control over population changes within its jurisdictional boundaries. With no notable changes in populations numbers and makeup, the vulnerability of the Corp to this hazard is unlikely to change. ➢ Changes in land use and development in the Corp are expected to be limited in the near future and thus are not likely to affect heavy rains and storm and associated impacts to the Corp. In addition, adherence to protective building codes for new development will assist in limiting future impacts and associated vulnerabilities of the Corp to this hazard.

Future Development
The District has no plans to acquire or develop new properties or add structures to support their District objectives. Further, the Corp noted that it has no control over future development within its District boundaries. Responsibility for growth and development within District boundaries resides with the County and City of Portola. Any development within the Plumas County Planning Area and the Corp will follow state and local building codes which should reduce the risk to future development in the Corp from heavy rains and storms. New critical facilities should be built to withstand hail damage, lightning, and thunderstorm winds. Changes in land use may also amplify the impacts of heavy rains and storms, as additional impervious surfaces can cause additional runoff and localized flooding throughout the Corp and the County Planning Area.

Wildfire (with smoke and air quality)
Likelihood of Future Occurrence–Highly Likely
Vulnerability–Extremely High
Hazard Profile
Wildland fire and the risk of a conflagration is an ongoing concern for the Plumas Corp. Throughout California, communities are increasingly concerned about wildfire safety as increased development in the foothills and mountainous areas and subsequent fire control practices have affected the natural cycle of fire regimes. Wildland fires affect grass, forest, and brushlands, as well as structures. Where there is human access to wildland areas, the risk of fire increases due to a greater chance for human carelessness and historical fire management practices. Historically, the fire season extends from early spring through late fall of each year during the hotter, dryer months; however, in recent years, the risk of wildfire has become a year around concern.

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Plumas County PC Annex F-49
Local Hazard Mitigation Plan Update
January 2026
Fire conditions arise from a combination of high temperatures, low moisture content in the air and fuel, accumulation of vegetation, and high winds. These weather conditions can result in red flag (e.g., fire weather) days, and can result in PSPS events in the Corp. While wildfire risk has predominantly been associated with more remote forested areas and wildland urban interface (WUI) areas, significant wildfires also occur in more populated developed areas. There is also the concern of wildfires occurring in these more remote, forested areas, that under certain weather conditions, can extend into areas not generally considered at a high risk to wildfire. Smoke and air quality also become an issue, both from fires occurring inside and outside of the Plumas County Planning Area and the Corp.

Current WUI mapping for Plumas County and the Plumas Corp is shown on Figure F-3.

Figure F-3 WUI for Plumas County Planning Area and the Plumas Corp Wildfire Smoke and Air Quality
Smoke from wildfires is made up of gas and particulate matter, which can be easily observed in the air. Air quality standards have been established to protect human health with the pollutant referred to as PM2.5 which consists of particles 2.5 microns or less in diameter. These smaller sizes of particles are responsible for adverse health effects because of their ability to reach the lower regions of the respiratory tract.

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Plumas County PC Annex F-50
Local Hazard Mitigation Plan Update
January 2026
Wildfire smoke can have negative effects to those who live in or near a fire burn area. Smoke and air pollution from wildfires can be a severe health hazard. Significant wildfires occurring in both Plumas County, nearby northern California communities, and elsewhere have created significant air pollution affecting area residents. This was the case during the 2021 Caldor Fire, as well as others that affected the Plumas County Planning Area.

Location and Extent
Wildfire can affect all areas of the Corp. CAL FIRE has estimated that the risk varies across the Corp and has created maps showing risk variance. Following the methodology described in Section 4.3.16 of the Base Plan, wildfire maps for the Plumas Corp were created. Figure F-4 shows the CAL FIRE State Responsibility Areas (SRA) and Federal Responsibility Areas (FRA) and their associated Fire Hazard Severity Zones (FHSZ) in the Corp. Figure F-5 shows the CAL FIRE Local Responsibility Areas (LRA) and their associated Fire Hazard Severity Zones (FHSZ) in the Corp. As shown on the maps, FHSZs within the Corp range from Moderate to Very High. Zoomed in maps for the SRA/FRA and the LRA are shown in Section 4.3.16 of the Base Plan.

Figure F-4 Plumas Corp – CAL FIRE SRA/FRA Fire Hazard Severity Zones

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Plumas County PC Annex F-51
Local Hazard Mitigation Plan Update
January 2026
Figure F-5 Plumas Corp – CAL FIRE LRA Fire Hazard Severity Zones Wildfires tend to be measured in structure damages, injuries, and loss of life as well as on acres burned.

Geographical FHSZ extents in the SRA/FRA are shown in Table F-9, while extents in the LRA are shown on Table F-10.

Table F-9 Plumas Corp – CAL FIRE SRA/FRA Fire Hazard Severity Zone Geographical Extents by Jurisdiction
Jurisdiction/
Fire Hazard
Severity Zones
Total Acres % of Total
Acres
Improved
Acres
% of Total
Improved
Acres
Unimproved
Acres
% of Total
Unimproved
Acres
City of Portola
Very High 5 0.0003% 3 0.003% 2 0.0002%
High 5 0.0003% 0.0001 0.0000001% 5 0.0003%
Moderate - - -

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Plumas County PC Annex F-52
Local Hazard Mitigation Plan Update
January 2026
Jurisdiction/
Fire Hazard
Severity Zones
Total Acres % of Total
Acres
Improved
Acres
% of Total
Improved
Acres
Unimproved
Acres
% of Total
Unimproved
Acres
NonWildland/NonUrban- - -
Outside of
Federal / State
Responsibility
Area
3,481 0.2% 2,234 2.4% 1,246 0.1%
City of Portola
Total
3,491 0.2% 2,237 2.4% 1,254 0.1%
Unincorporated Plumas County
Very High 1,454,532 87.0% 40,739 43.8% 1,413,793 89.5%
High 116,705 7.0% 19,400 20.9% 97,305 6.2%
Moderate 39,004 2.3% 6,405 6.9% 32,599 2.1%
NonWildland/NonUrban13,602 0.8% 0.01 0.00001% 13,602 0.9% Outside of
Federal / State
Responsibility
Area
44,775 2.7% 24,214 26.0% 20,560 1.3%
Unincorporated
Plumas County
Total
1,668,618 99.8% 90,759 97.6% 1,577,859 99.9%
Grand Total 1,672,109 100.0% 92,996 100.0% 1,579,113 100.0% Source: CAL FIRE
Table F-10 Plumas Corp – CAL FIRE LRA Fire Hazard Severity Zone Geographical Extents by Jurisdiction
Jurisdiction/
Fire Hazard
Severity Zones
Total Acres % of Total
Acres
Improved
Acres
% of Total
Improved
Acres
Unimproved
Acres
% of Total
Unimproved
Acres
City of Portola
Very High 3,235 0.2% 2,016 2.2% 1,219 0.1%
High 250 0.01% 221 0.2% 28 0.002%
Moderate 0 0.0% 0 0.0% 0 0.0%
Non-Wildland 0 0.0% 0 0.0% 0 0.0%
Outside of Local
Responsibility
Area
6 0.0004% 0.002 0.000002% 6 0.0004%
City of Portola
Total
3,491 0.2% 2,237 2.4% 1,254 0.1%

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Plumas County PC Annex F-53
Local Hazard Mitigation Plan Update
January 2026
Jurisdiction/
Fire Hazard
Severity Zones
Total Acres % of Total
Acres
Improved
Acres
% of Total
Improved
Acres
Unimproved
Acres
% of Total
Unimproved
Acres
Unincorporated Plumas County
Very High 1,400 0.1% 742 0.8% 658 0.04%
High 1,279 0.1% 588 0.6% 690 0.04%
Moderate 488 0.03% 258 0.28% 230 0.01%
Non-Wildland 41,625 2.5% 22,641 24.3% 18,984 1.2%
Outside of Local
Responsibility
Area
1,623,211 97.1% 66,542 71.5% 1,556,670 98.6%
Unincorporated
Plumas County
Total
1,668,003 99.8% 90,771 97.6% 1,577,231 99.9%
Grand Total 1,671,494 100% 93,009 100% 1,578,485 100%
Source: CAL FIRE
Past Occurrences
Disaster Declaration History
There has been eight state and six federal disaster declarations due to fire, as shown in Table F-11.

Table F-11 Plumas County – State and Federal Wildfire Disaster Declarations 1950-2025 Disaster Type State Declarations Federal Declarations
Count Years Count Years
Fire 8 1960 (unnamed), 1987(Clarks
Fire), 1999 (Bucks Fire), 2020
(twice – Bear Fire, North
Complex Fire), 2021 (three –
Dixie Fire, Monument Fire,
Lava Fire/Beckwourth
Complex)
6 1999 (Bucks Fire), 2008 (BTU
Lightning Complex), 2020
(twice – Bear Fire, North
Complex Fire), 2021 (twice –
Dixie Fire, Lava
Fire/Beckwourth Complex)
Source: Cal OES, FEMA
NCDC Events
The NCDC has tracked 15 wildfire events in the County dating back to 1993. Many more fires have occurred, but were not reported to the NCDC database.

Plumas Corp Events
The District noted the following large, damaging events: occurring since the last LHMPs. In addition to those highlighted below, the Plumas Corp noted that fire is an annual occurrence with many fires igniting.

While most fires are quickly suppressed, any ignition has the potential to become an out of control wildfire.

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Plumas County PC Annex F-54
Local Hazard Mitigation Plan Update
January 2026
2021 – The Dixie Fire ignited on July 13, 2021, in Butte County, California and soon spread across Plumas, Lassen, Tehama, and Shasta counties. It became the largest single (non-complex) wildfire in California history, burning 963,309 acres before full containment on October 25, 2021. Due to extreme fire behavior, including recurring pyrocumulus cloud formation and ember spotting up to a mile ahead, suppression efforts were extremely challenging. Originating in Butte County spreading to Plumas, Lassen, Tehama, and Shasta counties. The fire started on July 13, 2021, and was declared 100% contained on October 25, 2021.

From a forestry standpoint a great many of the acres of timber may be considered as a crop due to the cyclic harvesting practices and ongoing management techniques employed by the local lumber companies like Collins Pines and Sierra Pacific Industries. Additionally, the US Forest Service in the area employs very similar forest management techniques to provide additional harvest opportunities for local lumber companies.

The Dixie Fire destroyed approximately 1,300 structures and damaged 94 others. Many homes within the Dixie footprint survived the fire, but had significant impacts to the surrounding vegetation around the property and associated infrastructure such as water supply and solar power generation.

The town of Greenville suffered catastrophic losses, with most of its historic downtown area burned to the ground. A hotel, a restaurant, 2 gas/service stations, the local library branch, a pharmacy, several storefronts, a fire station with apparatus, a local tribal resource center with medical and dental clinics, and the post office were all lost during the fire. The community of Canyon Dam which was located 10 miles north of Greenville was razed by the fire as well. There was also fire related damage on the outskirts of Chester.

The following infrastructure damage occurred:
➢ Power infrastructure: Extensive damage to Pacific Gas & Electric (PG&E) transmission lines and utility poles, leading to widespread power outages. These power outages resulted in entire communities relying on generator supplied electricity for a full year or more after the incident. ➢ Water supply systems: Local water infrastructure was contaminated due to burned plastic pipes and exposure to hazardous debris. The water system within Greenville effectively collapsed due to the elevated demands from the firefighting resources.
➢ Telecommunications: Disruptions occurred as cell towers, fiber-optic lines, and electrical lines supplying the communication sites were impacted, affecting emergency communications. ➢ Highway closures: Portions of Highways 70, 36, and 44 were shut down due to fire activity, fallen trees, and hazardous conditions. Following the incident, closures highway and road closures were widespread in order to mitigate hazards associated with the post fire hazard tree removal, road corridor stabilization
➢ Transportation networks: Roads, bridges, and highways sustained damage from intense heat, falling trees, and rockslides.

The District also noted the following impacts from the fire:
➢ The Greenville Library, post office, businesses, and historic buildings were completely destroyed. ➢ Severe air quality degradation occurred across Northern California, Nevada, and Oregon, with smoke plumes reaching as far as the East Coast.

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Plumas County PC Annex F-55
Local Hazard Mitigation Plan Update
January 2026
➢ Soil erosion and watershed contamination from fire retardants and burned vegetation threatened local water sources.
➢ Damages were estimated at $1.15 billion, with further uninsured losses significantly adding to the financial burden.

PG&E announced a $45 million settlement with counties affected by the fire. 2020 – The North Complex Fire was a massive wildfire complex that burned in the Plumas National Forest in Northern California in the counties of Plumas and Butte. Twenty-one fires were started by lightning on August 17, 2020; by September 5, all the individual fires had been put out with the exception of the Claremont and Bear Fires, which merged on that date, and the Sheep Fire, which was then designated a separate incident. On September 8, strong northeast winds caused the Bear/Claremont Fire to explode in size, rapidly spreading to the southwest. On September 8, 2020, the towns of Berry Creek and Feather Falls were immediately evacuated at 3:15 p.m. PDT with no prior warning. By September 9, 2020, the towns of Berry Creek and Feather Falls in Butte County had been leveled, with few homes left standing. The fire threatened the City of Oroville, before its westward spread was stopped. The fire killed 16 people and injured more than 100. The complex burned an estimated 318,935 acres (uncertain how many acres were in Plumas County specifically), and was 100% contained on December 3. The fire was managed by the U.S. Forest Service in conjunction with Cal Fire, with the primary incident base in Quincy. At the time, the North Complex Fire was the eighth-largest in California's history and was the deadliest fire in the 2020 California wildfire season.

Smoke from the fire created extremely unhealthy air conditions in Quincy and nearby communities for several weeks. After the fire grew explosively in size on September 9, smoke reached the Sacramento Valley and the San Francisco Bay area (where the effects of the smoke led to the day being referred to as Orange Skies Day) with ash falling from the sky between Danville, San Jose, and San Francisco.

Additionally, the US Forest Service in the area employs very similar forest management techniques to provide additional harvest opportunities for local lumber companies.

The District also noted the following impacts from the fire:
➢ Greater than 100 injuries to firefighters and public between Plumas and Butte Counties ➢ 16 (14 residents of Berry Creek and 2 residents of Feather Falls, both communities are in Butte county.) ➢ Approximately 2,471 structures were destroyed, including homes and businesses. ➢ The towns of Brush Creek and Berry Creek were nearly completely destroyed. ➢ Significant damage to above ground power transmission and distribution infrastructure. Significant damage to roads and associated drainage features from falling trees, rockslides and post rain debris flows.
➢ Roads and bridges suffered structural damage due to the intense heat. ➢ The fire posed a significant threat to the Oroville Dam. ➢ Significant business/economic impacts due to widespread evacuations for extended periods of time.

Additionally, economic impacts were realized from National Forest closures that halted timber harvest operations across the county on Federal lands. Recreation is a large part of the economy of the local

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Plumas County PC Annex F-56
Local Hazard Mitigation Plan Update
January 2026
area., Forest closures and unhealthy/unsafe environmental conditions halted the flow of people to the area which ultimately impacted the earnings of local businesses. ➢ Roads were closed into evacuated areas during the incident. Post incident activities created significant impacts on traffic flow through affected areas.
➢ The fire caused long-term environmental damage, leading to erosion concerns, water quality issues, and habitat destruction.
➢ Wildlife displacement and destruction of ecological zones in Plumas National Forest. ➢ Approximately $450 million in damages.

Climate Change and Wildfire
It is likely that climate change will increase the chance of future occurrence as well as future impacts from wildfire. More information on future impacts to the Corp can be found in the Future Conditions/Future Development section of the Vulnerability Assessment below.

Vulnerability to Wildfire
Risk and vulnerability to the Corp from wildfire is of significant concern. Wildfires that occur in the Corp occur from a variety of both natural and manmade causes. The District can be affected both by fires that start on or near District lands as well as those that start elsewhere and move into the Corp. In addition to burning large areas of land, air quality can be affected in the Corp by smoke from fires occurring inside the Corp as well as those from many miles away.

The whole of the Corp is at some measure of vulnerability to wildfire. An assessment of a community’s vulnerability to wildfire begins with an understanding of local exposure to wildfire. This is included in the Local Concerns section below followed by a discussion of the Corp’s Assets at Risk to this hazard.

Plumas County includes 29 recognized Communities at Risk (CAR): Almanor, Beckwourth, Belden, Blairsden, Bucks Lake, Canyon Dam, Caribou, Chester, Clio, Crescent Mills, Cromberg, Delleker, Genesee, Graeagle, Greenville, Hamilton Branch, Indian Falls, Johnsville, Keddie, La Porte, Meadow

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Plumas County PC Annex F-57
Local Hazard Mitigation Plan Update
January 2026
Valley, Mohawk, Paxton, Portola, Prattville, Quincy-East Quincy, Seneca, Taylorsville, and Twain. Plumas County has a higher risk of wildfires than 98% of the other counties in the United States. In addition, the State’s Fire Hazard Severity Zone map identifies the majority of the communities in Plumas County as “Very High Severity” (76.2%), with few in the “High” (19.1%) and “Moderate” (4.7%) categories.

In 2020 and 2021, a collective 947,632 acres within Plumas County were burned by the Dixie, North Complex, and other large wildfires. This area totals a startling 57% of the County. During the Dixie Fire of 2021, Plumas County lost the towns of Greenville, Indian Falls, Warner Valley, and Canyon Dam destroying nearly all of these town’s infrastructure and decimating the surrounding forests. Without their homes, forest, and basic infrastructure, most of these communities' populations were displaced, contributing to an ongoing housing crisis in Plumas County. It is critically important to strategically protect the remaining “green” corridor in Plumas County, recover fire-impacted communities, and implement parcelspecific hazard mitigation with a long-term vision for resiliency.

The North Complex Fire and Dixie Fire underscore the urgent need for increased wildfire mitigation efforts, including:
➢ Forest thinning and controlled burns to reduce fuel loads. ➢ Improved evacuation planning and emergency communication systems. ➢ Hardening of infrastructure such as underground power lines and fire-resistant building materials. ➢ Greater investment in home hardening and defensible space programs for homeowners in high-risk areas.

The likelihood of another large-scale wildfire in Plumas County remains extremely high due to the following factors:
➢ Drought conditions: Persistent dry weather has left forests vulnerable to ignition and rapid spread. ➢ Fuel accumulation: Dead and drought-stressed trees provide excessive fuel for future fires. ➢ Climate change: Rising temperatures and prolonged fire seasons increase the risk of extreme wildfires.

The District does not have data on smoke impacts or air quality issues, however the PCFSC maintains an air purifier loan program that is utilized during fire season by residents with respiratory issues.

People and Populations
All District staff and the populations within District boundaries are at some vulnerability to wildfire.

Certain vulnerable populations are at greater risk to the effects of wildfire as well as smoke and air quality issues that wildfires bring. Vulnerable populations include the unhoused, infants and children under age five and their caregivers, the elderly (65 and older), individuals with respiratory issues, individuals dependent on medical equipment, individuals who exercise, recreate, or work (like District staff) outdoors, and individuals with impaired mobility.

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Plumas County PC Annex F-58
Local Hazard Mitigation Plan Update
January 2026
Structures and Critical Facilities and Infrastructure
All structures in the Corp have some risk to wildfire. Wildfire presents a threat to critical facilities and infrastructure. The District’s one office facility is at risk to wildfire asshown in Table F-2. Critical facilities and infrastructure can also be impacted should a PSPS occur.

Natural, Historic, and Cultural Resources
Natural, historic, and cultural resources located within areas at risk to wildfire would be vulnerable. Should a wildfire occur in the Corp, the impacts to natural, historic and cultural resources could be extensive and include air pollution, contamination from water runoff containing toxic products, other environmental discharges or releases from burned materials affecting soils, habitat areas, wildlife, and aquatic resources, and total destruction of natural resources. Debris and runoff from burned areas can affect reservoirs and rivers in the Corp. Historic and cultural resources can be damaged or destroyed and are often more vulnerable due to their older age, construction type, and lack of fire prevention infrastructure such as sprinklers.

Impacts from Wildfire
Potential impacts from wildfire include loss of life and injuries; damage to structures, critical facilities and infrastructure, and other improvements, natural and cultural resources, croplands, and timber; and loss of recreational opportunities. Out of control wildfires can have catastrophic impacts. Wildfires can cause short-term and long-term disruption to the Corp. Fires can have devastating effects on watersheds through loss of vegetation and soil erosion, which may impact the Corp by changing runoff patterns, increasing sedimentation, reducing natural and reservoir water storage capacity, and degrading water quality. Fires can also affect air quality in the Corp; smoke and air pollution from wildfires can be a severe health hazard.

Smoke impacts may come from wildfires outside the Corp, as well as from within.

The impacts of a fire are felt long after the fire is extinguished. In addition to the loss of property in fires, the loss in vegetation and changes in surface soils alters the environment. When supporting vegetation is burned, hillsides become destabilized and prone to erosion. The burnt surface soils are harder and absorb less water. When winter rains come, this leads to increased runoff, erosion, and landslides in hilly areas.

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Plumas County PC Annex F-59
Local Hazard Mitigation Plan Update
January 2026
California communities since the previous LHMP have created significant air pollution affecting area residents. District residents have been affected by wildfire smoke and poor air quality, from fires both within the County and from those much further away.

Impacts to identified assets at risk to this hazard and the overall vulnerability of the Corp may be affected in the future by climate change (which was discussed in the hazard profile above), changes in population patterns (migration, density, or the makeup of socially vulnerable populations), and changes in land use and development. These are discussed in the Future Conditions/Future Development discussion below.

Future Conditions
Future conditions may be affected by climate change, changes in population patterns (migration, density, or the makeup of socially vulnerable populations), and changes in land use and development. Findings on this for the Plumas Corp include the following:
➢ Climate change is likely to exacerbate future wildfire conditions and associated impacts and vulnerability of the Corp to wildfire.
➢ Population projections within the jurisdictional boundaries of the Corp show the population to be slightly declining. It is unknown how population patterns and demographics will change in the near future. The District may add staff, but this number would be small. The District noted that it has no control over population changes within its jurisdictional boundaries. With no notable changes in populations numbers and makeup, the vulnerability of the Corp to this hazard is unlikely to change. ➢ Changes in land use and development in the Corp are expected to be limited in the near future and thus would have possible associated wildfire impacts to the Corp. Additional development may contribute to an increase in wildfire ignitions. However, adherence to protective building codes for new development will assist in limiting future impacts and associated vulnerabilities of the Corp to this hazard.

Future Development
The District has no plans to acquire or develop new properties or add structures to support their District objectives. Further, the Corp noted that it has no control over future development within its District boundaries. Responsibility for growth and development within District boundaries resides with the County and City of Portola. Any development within the Plumas County Planning Area and the Corp will follow state and local building codes which should reduce the risk to future development in the Corp from high wind events. Additional growth and development within moderate or higher fire hazard severity zones in the Plumas County Planning Area and the Corp would place additional assets at risk to wildfire. More vulnerable populations may experience a disproportionate impact from wildfire, and should be considered as development continues. County and City building codes are in effect and should continue to be updated to meet new wildfire requirements to reduce impacts to future development. Fire hydrants, defensible

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Plumas County PC Annex F-60
Local Hazard Mitigation Plan Update
January 2026
space, well production, water storage, and distribution should all be considered in future development planning. New facilities will be built to the most current California Building standards for wildfire.

F.5 Capability Assessment
Capabilities are the programs and policies currently in use to reduce hazard impacts or that could be used to implement hazard mitigation activities. This capabilities assessment is divided into five sections:
regulatory mitigation capabilities, administrative and technical mitigation capabilities, fiscal mitigation capabilities, mitigation education, outreach, and partnerships, and other mitigation efforts.

F.5.1. Regulatory Mitigation Capabilities
Table F-12 lists regulatory mitigation capabilities, including planning and land management tools, typically used by local jurisdictions to implement hazard mitigation activities and indicates those that are in place in the Plumas Corp.

Note: The District does not have the authority to regulate land use and development within its jurisdiction.

Authority for promulgating and enforcing zoning, land use, and development requirements falls to counties and incorporated communities. As such development within the Corp’s jurisdictional boundaries will conform to the zoning and land use development ordinances and building codes of the county or incorporated community in which the Corp is located.

Table F-12 Plumas Corp’s Regulatory Mitigation Capabilities Plans
In Place
Y/N
Does the plan address hazards? Can the plan be used to
carry out mitigation actions? When was it last updated?? Capital Improvements Plan N
Climate Change Adaptation Plan N
Community Wildfire Protection Plan Y Plan addresses hazards and can be used to carry out mitigation actions. Was last updated in 2019. Plumas Corp staff works with the PCFSC to update this Plan.

Comprehensive/Master Plan N
Continuity of Operations Plan N
Economic Development Plan N
Land Use Plan N
Local Emergency Operations Plan N
Stormwater Management Plan N
Transportation Plan N
Other

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Plumas County PC Annex F-61
Local Hazard Mitigation Plan Update
January 2026
Land Use Planning and Ordinances Y/N
Is the ordinance an effective way to reduce hazard
impacts?
Is the ordinance adequately administered and enforced?
Acquisition of land for open space and
public recreation use
N/A
Building code N/A
Flood insurance rate maps N/A
Floodplain ordinance N/A
Natural hazard-specific ordinance
(stormwater, steep slope, wildfire)
N/A
Subdivision ordinance N/A
Zoning ordinance N/A
Other
How can these capabilities be expanded and improved to reduce risk? PC will continue to support the Fire Safe Council’s work on updating the CWPP, expanding Firewise communities, and working with the County on any ordinances related to wildfire.

Source: Plumas Corp
F.5.2. Administrative/Technical Mitigation Capabilities Table F-13 identifies the Corp department(s) responsible for activities related to mitigation and loss prevention in the Plumas Corp.

Table F-13 Plumas Corp’s Administrative and Technical Mitigation Capabilities Administration
In
Place
Y/N
Describe capability
Is coordination effective?
Staff
Is staffing adequate to enforce regulations?
Is staff trained on hazards and mitigation?
Is coordination between agencies and staff effective?
Chief Building Official N
Civil Engineer, including dam and levee
safety
N
Community Planner N
Emergency Manager N
Floodplain Administrator N
GIS Coordinator Y
Planning Commission N
Other Y Multi-jurisdiction Project Managers; conceptual project development

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Plumas County PC Annex F-62
Local Hazard Mitigation Plan Update
January 2026
Technical Y/N
Has capability been used to assess/mitigate risk in the past?
Grant writing Y Has been used in past.

Hazard data and information Y Has been used in past.

GIS analysis Y
Mutual aid agreements
Other Y Yes, grant & project administration
How can these capabilities be expanded and improved to reduce risk? Administrative and technical mitigation capabilities can be expanded by leveraging inter-organizational partnerships to minimize redundant efforts and increase consistency of technical data utilized for mitigation practices. Targeted recruitment of district staff members can further enhance the administrative and technical capacity of the district by matching future staff knowledge, skills, and abilities with organizational needs. Emphasizing professional development can further expand the overall administrative and technical mitigation capabilities by combining existing corporate knowledge with new or enhanced skills of existing staff.

Source: Plumas Corp
F.5.3. Fiscal Mitigation Capabilities
Table F-14 identifies financial tools or resources that the Corp could potentially use to help fund mitigation activities.

Table F-14 Plumas Corp’s Fiscal Mitigation Capabilities Funding Resource
In
Place
Y/N
Has the funding resource been used in past and
for what type of activities?
Could the resource be used to fund future
mitigation actions?
Capital improvements project funding N
Community Development Block Grant N
Federal funding programs (non-FEMA) Y Plumas Corp (along with PCFSC) has managed numerous projects that are funded through the

USFS, USBOR
Fees for water, sewer N
Capacity fees for new development N
State funding programs Y Plumas Corp has received funding from CA State Water Resources Control Board and other state
agencies for several types of projects including
forest health, stream, and meadow restoration.

Stormwater utility fee N
Other Y Plumas Corp funding from numerous private nongovernmental organizations for restoration projects that offer multiple benefits, including mitigating
some of above hazards.

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Plumas County PC Annex F-63
Local Hazard Mitigation Plan Update
January 2026
Funding Resource
In
Place
Y/N
Has the funding resource been used in past and
for what type of activities?
Could the resource be used to fund future
mitigation actions?
How can these capabilities be expanded and improved to reduce risk? Additional funding opportunities would perpetuate existing programs and allow them to grow in scale to more closely match the needs of the communities we serve.

Source: Plumas Corp
F.5.4. Mitigation Education, Outreach, and Partnerships Table F-15 identifies education and outreach programs and methods already in place that could be/or are used to implement mitigation activities and communicate hazard-related information.

Table F-15 Plumas Corp’s Mitigation Education, Outreach, and Partnerships Program/Organization
In
Place
Y/N
How widespread are each of these in your
community?
Community newsletters Y PC distributes a quarterly newsletter to local community members, stakeholders, and partners
Hazard awareness campaigns (such as Firewise,
Storm Ready, Severe Weather Awareness Week,
school programs, public events)
Y PC provides educational information via school
presentations, field trips, community tours, and
participation in public events, such as Earth Day
and the locally hosted Wild & Scenic Environmental
Film Festival.

Local news N
Organizations that interact with underserved and
vulnerable communities
N
Social media Y PC shares local weather and storm information on social media..

How can these capabilities be expanded and improved to reduce risk? Continued growth of newsletter mailing list and increased social media postings and followers Source: Plumas Corp
F.5.5. Other Mitigation Efforts
The District has many other completed or ongoing mitigation projects/efforts that include the following:
➢ After the 1997 flood, the Indian Valley Flood Management Study (CH2MHill, 1997), was done for the Plumas County Dept. of Public Works. The Study identified and surgically evaluated a number of flood mitigation measures. Meadow & floodplain restoration in the upper watershed was determined to be one of the more feasible and effective measures. Upper watershed work has the potential to lower flood stages 1- 3 feet by attenuating peak inflows to the valley, depending on the spatial extent of that restoration work. To date, Plumas Corporation has implemented restoration work on over 2,800 acres

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Plumas County PC Annex F-64
Local Hazard Mitigation Plan Update
January 2026
of meadow floodplain in the Indian Creek basin. Varying levels of meadow floodplain work has also been implemented in the Middle Fork, North Fork and Spanish Creek watersheds since 1995. ➢ Most of Plumas Corporation/Fire Safe Council projects are considered climate adaptation activities, loosely following the Feather River Watershed Management Strategy (2004). Restoring stream/floodplain connectivity with meadow restoration promotes significant watershed resilience against floods and drought exacerbated by climate change. To date, over 70 miles of channel and 5,600 acres of floodplain have been restored in the Corp.

F.6 Mitigation Strategy
F.6.1. Mitigation Goals and Objectives
The Plumas Corp adopts the hazard mitigation goals and objectives developed by the HMPC and described in Chapter 5 Mitigation Strategy.

F.6.2. NFIP Mitigation Strategy
The District does not participate in the NFIP, as it is not an eligible participant. A few of the Corp’s projects work to reduce impacts from flooding thus furthering the objectives of the NFIP.

F.6.3. Mitigation Actions
The Planning Team for the Plumas Corp identified and prioritized the following mitigation actions based on the risk assessment. Background information and information on how each action will be implemented and administered, such as ideas for implementation, responsible office, potential funding, and timeline are also included. The following hazards were considered a priority to the Corp for purposes of mitigation action planning based on criteria detailed in Chapter 5:
➢ Agricultural Hazards (Severe Weather/Pests/Invasive Species) ➢ Climate Change
➢ Drought & Water shortage (w/tree mortality)
➢ Floods: 1%/0.2% annual chance (w/levee failure)
➢ Floods: Localized Stormwater
➢ Severe Weather: Extreme Heat
➢ Severe Weather: Heavy Rain and Storms (Wind, Hail, Lightning) ➢ Wildfire (w/smoke and air quality)
Non-priority hazards to the Corp for mitigation planning include:
➢ Dam Failure
➢ Earthquake
➢ Hazardous Materials Transport
➢ Landslide, Mudslide, and Debris Flow
➢ Severe Weather: Extreme Cold, Freeze, and Snow (w/avalanche) ➢ Severe Weather: High Winds and Tornado
➢ Volcano

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Plumas County PC Annex F-65
Local Hazard Mitigation Plan Update
January 2026
It should be noted that many of the projects submitted by each jurisdiction in Table 5-4 in the Base Plan benefit all jurisdictions whether or not they are the lead agency. Further, many of these mitigation efforts are collaborative efforts among multiple local, state, and federal agencies. In addition, the countywide public outreach action, as well as many of the emergency services actions, apply to all hazards and jurisdictions regardless of hazard priority. Collectively, this LHMP’s multi-jurisdictional mitigation strategy includes only those actions and projects which reflect the actual priorities and capacity of each jurisdiction to implement over the next 5-years covered by this plan. It should further be noted, that each jurisdiction has focused on identifying those mitigation actions and projects to address their priority hazards, which are both realistic and reasonable for them to implement for this 5-year planning process, and would like to preserve their right to modify hazard priorities should future projects be identified where the implementing jurisdiction has the future capacity to implement.

Mitigation Actions
Action 1. Hazardous Fuels Reduction – Implementation, Monitoring, and Maintenance Hazards Addressed: Wildfire
Goals Addressed: 1, 2, 3, 4, 5, 6
Issue/Background (Problem Statement): Plumas County faces significant wildfire risk due to overgrown forest conditions, drought-stressed vegetation, extensive tree mortality from bark beetle infestations, and the wildland-urban interface (WUI) where homes and infrastructure are adjacent to wildland fuels. In recent years, there has been intensified fire weather conditions, creating longer fire seasons and more extreme fire behavior. Dense forest conditions create dangerous fuel loads that threaten public safety, critical infrastructure, evacuation routes, and community assets. Without proactive hazardous fuels reduction, the county remains vulnerable to catastrophic wildfires that could result in loss of life, property damage, and environmental degradation.

Project Description: Implement comprehensive hazardous fuels reduction treatments including mechanical thinning, mastication, hand thinning, prescribed burning, and strategic placement of fuel breaks throughout high-risk areas of Plumas County. Focus on protecting evacuation routes, defensible space around structures, critical infrastructure corridors, and municipal water supplies. Create, monitor, and maintain fuel breaks to slow fire spread and provide safe zones for firefighting operations. Coordinate treatments across jurisdictional boundaries to create landscape-scale fire resilience.

Other Alternatives:
➢ No action - Accept existing wildfire risk with reactive suppression response only ➢ Structure-focused approach only - Limit activities to defensible space around individual properties ➢ Suppression-only strategy - Rely entirely on firefighting resources without proactive fuel reduction ➢ Regulatory approach only - Implement stricter building codes and vegetation management ordinances without active treatment
Existing Planning Mechanism(s) through which Action Will Be Implemented: Plumas County Community Wildfire Protection Plan (CWPP), 2025 Hazardous Fuels Assessment - Deer Creek Resources,

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Plumas County PC Annex F-66
Local Hazard Mitigation Plan Update
January 2026
LLC, Local Hazard Mitigation Plan (LHMP), CAL FIRE , U.S. Forest Service Forest Health and Restoration programs
Responsible Office/Partners:
➢ Plumas County Fire Safe Council
➢ Plumas Corporation Executive Director
➢ CAL FIRE
➢ U.S. Forest Service (Forest Health Protection, Plumas National Forest and Lassen National Forest) ➢ Feather River Resource Conservation District
➢ Plumas County Planning and Public Works Departments
➢ Local Fire Protection Districts
➢ Utility companies (hazard tree management along powerlines) Benefits (Losses Avoided):
➢ Reduced hazardous fuel loads
➢ Improved firefighter and public safety along evacuation routes and public spaces. ➢ Enhanced forest health and resilience to drought and pests. ➢ Protection of homes, infrastructure, and utilities from wildfire spread. ➢ Increased availability of biomass and wood products as beneficial by-products of removal.

Potential Funding (Local Budgets, Grant Funds, etc.): Cost-effective partnerships with local timberland owners (lower per acre rates). CAL FIRE grants, FEMA HMGP, USDA Forest Service grants, California Climate Investments, streamlined EPP permitting, and other local, state, federal, and private grants to be identified
Timeline: 2026 and ongoing throughout the duration of the plan Project Priority (High, Medium, Low): High
Action 2. Last Chance Creek Watershed Floodplain Restoration Project Hazards Addressed: Ag Hazard: Severe Weather; Climate Change; Drought & Water Shortage (w/tree mortality; Flood (1%/0.2% annual chance and Localized Stormwater); Severe Weather: Extreme Heat, Heavy Rains and Storms; Wildfire (w/smoke and air quality) Goals Addressed: 1, 2, 3, 4, 5, 6
Issue/Background (Problem Statement): The 204 square mile Last Chance Creek watershed is one of two large sub watersheds to Indian Creek. Indian Creek flows through Genesee and Indian valleys where flooding and channel instability are current hazards to the populace. The Last Chance Creek watershed contains one of the longest contiguous meadow floodplain systems in the Sierra Nevada Mountains. Last Chance Creek is severely downcut (incised) throughout the 36 miles of meadow floodplain. Principal stressors were logging railroad grades built in the low gradient meadow in the 1930s & ‘40s, channel modification, livestock grazing, and roads. These incised channels funnel all flows downstream, rapidly draining out this headwater basin into the populated Genesee and Indian valleys.

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Plumas County PC Annex F-67
Local Hazard Mitigation Plan Update
January 2026
Loss of floodplain function and the rapid drainage of these headwater basins reduces the meadow’s ability to capture and store springtime snowmelt and rain as shallow groundwater. Sixty percent of California’s water supply originates in the Sierra Nevada, and meadows are a key component of that supply, helping to regulate water flow, temperature, and quality. As the headwaters of the State Water Project, the Feather River Watershed provides water to over 26 million Californians. Although wet meadows are a less than one percent of the overall landscape in Plumas County, meadows’ unique hydrologic and ecological functions are recognized as being vital to watershed health and are valued for the ecosystem goods and services they provide, such as crucial habitat for many endemic and special status wildlife species. Known as biological diversity hot spots, healthy meadows provide refugia for wildlife during droughts and wildfire. Wet and moist meadows sequester carbon in the soil, where it isn’t susceptible to being lost in a wildfire. In addition, functioning meadow floodplains provide natural fire breaks reducing fire intensities and rate of spread.

Project Description: The project is primarily located on public lands managed by USDA Forest ServicePlumas National Forest. The principal objective of the restoration work is to raise the hydraulic base level of the channel/floodplain system back to the historic meadow surface. This typically allows normal stream flows to access pre-existing remnant channels, while flood flows spread across the expansive floodplain surface. Longer residence times allows for enhanced infiltration to shallow and deeper groundwater basins, while filtering sediment and nutrients into the meadow ecosystem. This longer residence time in a functional floodplain reduces the pulse in flows downstream by allowing water to spread out and discharge downstream more slowly. Restoring floodplain function may be accomplished utilizing a variety of techniques, including complete and partial channel fill, raised riffles, and use of process-based channel structures (i.e., beaver dam analogs and post-assisted log structures), to name a few. Treatments would be specific to individual site conditions and constraints.

Other Alternatives: none
Existing Planning Mechanism(s) through which Action Will Be Implemented: Feather River Watershed Strategy (2004), Upper Feather River Integrated Regional Water Management Plan (2016), Tributaries Forest Recovery Project Environmental Assessment & Decision Notice (2025), California State Water Action Plan (2014), Sierra Nevada Conservancy 2024-2029 Strategic Plan (2024) Responsible Office/Partners: Plumas Corporation Executive Director, Plumas National Forest, Plumas County, private landowners
Benefits (Losses Avoided): Reduction in flood stage in Genesee and Indian valleys, avoiding damage/loss to agricultural productivity, ranch/farm infrastructure, and residential homes; Reduction in sediment supply downstream, improving water quality for aquatic resources, recreation, and agricultural irrigation;

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Plumas County PC Annex F-68
Local Hazard Mitigation Plan Update
January 2026
Reduction in water temperatures, improving water quality for aquatic species and recreation; Increased surface water residence time extending surface water availability for wildlife and vegetation, and allowing for enhanced infiltration to shallow and deeper groundwater basins mitigating impacts from drought and water shortage, climate change, and wildfire.

Potential Funding (Local Budgets, Grant Funds, etc.): Estimated costs- $12,000,000. Grants- State grant programs via CA Wildlife Conservation Board and Sierra Nevada Conservancy; Plumas National Forest Dixie Fire funds; Corporate Investments- Microsoft, Coca-Cola, Disney, Proctor and Gamble, etc.

Timeline: 2026-2035
Project Priority (High, Medium, Low): High
Action 3. Mountain Meadows Watershed Floodplain Restoration Project Hazards Addressed: Ag Hazard: Severe Weather; Climate Change; Drought & Water Shortage (w/tree mortality; Flood (1%/0.2% annual chance and Localized Stormwater); Severe Weather: Extreme Heat, Heavy Rains and Storms; Wildfire (w/smoke and air quality) Goals Addressed: 1, 2, 3, 4, 5, 6
Issue/Background (Problem Statement): The 153 mi2 Mountain Meadows watershed is the northeastern headwaters of the North Fork Feather River. The Mountain Meadows basin is located in southwestern Lassen County, but drains immediately into Plumas County. There are 7,500 acres of meadow in the basin, of which 1016 acres of floodplain have been or is being restored, and ~1070 additional acres are in planning.

The unrestored sections of Goodrich Creek, McKenzie Creek, Duffy Creek and Robbers Creek are severely downcut (incised). Principal stressors were logging railroad grades built in the low gradient meadow in the 1910’s & ‘20’s, channel modification, livestock grazing, and roads. These incised channels capture and contain all flows, rapidly draining out of the basin into Plumas County.

Loss of floodplain function and the rapid drainage of these headwater basins reduces the meadows’ ability to capture and store springtime snowmelt and rain as shallow groundwater. Sixty percent of California’s water supply originates in the Sierra Nevada, and meadows are a key component of that supply, helping to regulate water flow, temperature, and quality. As the headwaters of the State Water Project, the Feather River Watershed provides water to over 26 million Californians. Although wet meadows are a less than one percent of the overall landscape in the Sierra Nevada mountains, meadows’ unique hydrologic and ecological functions are recognized as being vital to watershed health and are valued for the ecosystem goods and services they provide, such as crucial habitat for many endemic and special status wildlife species. Known as biological diversity hot spots, healthy meadows provide refugia for wildlife during droughts and wildfire. Wet and moist meadows sequester carbon in the soil, where it isn’t susceptible to being lost in a wildfire. In addition, functioning meadow floodplains provide natural fire breaks reducing fire intensities and rate of spread.

From 2016 to 2023, 5 miles and 804 acres of floodplain has been restored by Plumas Corporation. The work restored the hydraulic base level of Greenville Creek, East Creek, Upper Goodrich Creek, and Mountain Meadows Creek back to the historic meadow level, recovering crucial floodplain function. The

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Plumas County PC Annex F-69
Local Hazard Mitigation Plan Update
January 2026
next project in the queue is McKenzie Meadow- Phase 1, a 212-acre project beginning construction in Sept. 2025. The 492-acre McKenzie Meadow- Phase 2 is currently in the design phase. Implementation funding is being sought. The 579-acre Lower Goodrich/Moonlight Road Project is also in the design, CEQA/NEPA review and permitting phase. Implementation funding is being sought for implementation in 2026.

Project Description: The project occurs on private lands owned by Sierra Pacific Industries, Collins Pine, and Red River Forests. The principal objective of the restoration work is to raise the hydraulic base level of the channel/floodplain system back to the historic meadow surface. This typically allows normal stream flows to access pre-existing remnant channels, while flood flows spread across the expansive floodplain surface. Longer residence times allows for enhanced infiltration to shallow and deeper groundwater basins, while filtering sediment and nutrients into the meadow ecosystem. This longer residence time in a functional floodplain reduces the pulse in flows downstream by allowing water to spread out and discharge downstream more slowly. Restoring floodplain function may be accomplished utilizing a variety of techniques, including complete and partial channel fill, raised riffles, and use of process-based channel structures (i.e., beaver dam analogs and post-assisted log structures), to name a few. Treatments would be specific to individual site conditions and constraints.

Other Alternatives: none
Existing Planning Mechanism(s) through which Action Will Be Implemented: Upper Feather River Integrated Regional Water Management Plan (2016), Mountain Meadows Watershed Restoration Action Plan (2013), California State Water Action Plan (2014), Sierra Nevada Conservancy 2024-2029 Strategic Plan (2024)
Responsible Office/Partners: Plumas Corporation Executive Director, private landowners Benefits (Losses Avoided): Reduction in flood stage into Lake Almanor, avoiding damage/loss to recreational infrastructure, residential homes, agricultural productivity, ranch/farm infrastructure, and reducing stress on dam infrastructure; Reduction in sediment supply downstream, improving water quality for aquatic resources, recreation, and agricultural irrigation; Reduction in water temperatures, improving water quality for aquatic species and recreation; Increased surface water residence time extending surface water availability for wildlife and vegetation, and allowing for enhanced infiltration to shallow and deeper groundwater basins mitigating impacts from drought and water shortage, climate change, and wildfire.

Potential Funding (Local Budgets, Grant Funds, etc.): Estimated costs- $5,000,000. Grants- State grant programs via CA Wildlife Conservation Board and Sierra Nevada Conservancy; Plumas National Forest Dixie Fire funds; Corporate Investments- Microsoft, Coca-Cola, Disney, Proctor and Gamble, etc.

Timeline: 2026-2035
Project Priority (High, Medium, Low): High
Action 4. Upper Feather River Watershed Post-Fire Water Quality Monitoring Project Hazards Addressed: Flood (1%/0.2% annual chance and Localized Stormwater, Severe Weather: Heavy Rains and Storms; Wildfire (w/ smoke and air quality)

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Plumas County PC Annex F-70
Local Hazard Mitigation Plan Update
January 2026
Goals Addressed: 1, 2, 3, 4, 5, 6
Issue/Background (Problem Statement): California’s variable climate frequently creates a pattern of cascading hazards in which multiple drought years can be followed by extreme heat and wildfire and subsequent wet years. Wildfires leave behind a hydrophobic soil surface layer that increases surface runoff; when combined with precipitation or extreme rainfall events, surface runoff can be significantly degraded by ash, nutrients, metals, combustion byproducts from anthropogenic sources, debris torrents, and sediment.

Many beneficial uses of receiving surface waters can be impaired, including human health/drinking water, recreation, fish consumption, and wildlife/ecosystems. A ready-to-deploy water quality monitoring program can be implemented during storm events post-fire to detect the threats to beneficial uses that can be used to tailor the type and location of remediation and restoration actions.

Project Description: Plumas Corporation has been conducting monitoring at key locations in the Upper Feather River watershed for more than 25 years. A post-fire water quality surveillance program will be developed during a fire that tiers to this program and can be supplemented by existing long-term data. As the rainy season approaches post-fire, incoming weather systems will be closely tracked to implement sampling during the first precipitation events that are expected to produce surface runoff. The monitoring plan will identify sample locations based on the extent/intensity of the wildfire, quality assurance/quality control (QA/QC) procedures, chain of custody requirements, the selected independent laboratory for analysis, and frequency of sampling. Constituents sampled will vary based on the degree of wildland-urban interface (WUI) in the watershed impacted by the wildfire, but will be selected from the following broad categories: field measurements (e.g., conductivity, temperature, etc.); minerals and solids (e.g., alkalinity, total suspended solids, E. coli, etc.), nutrients (ammonia, phosphorus, total organic carbon (TOC), etc.), total and dissolved metals (e.g., aluminum, arsenic, nickel, etc.), polycyclic aromatic hydrocarbons (PAHs), and polychlorinated biphenyls (PCBs).

Other Alternatives: none
Existing Planning Mechanism(s) through which Action Will Be Implemented: Feather River Watershed Working Group – Northern California, Feather River Watershed Strategy (2004), Upper Feather River Integrated Regional Water Management Plan (2016), California State Water Action Plan (2014) Responsible Office/Partners: Plumas Corporation Executive Director, Plumas National Forest, Plumas County, private landowners, Central Valley Regional Water Quality Control Board, California Department of Water Resources
Benefits (Losses Avoided): Mitigating damage/loss to cold and warmwater fish habitats; preventing human health impacts due to water quality impairment (from drinking water, contact recreation, and fish consumption).

Potential Funding (Local Budgets, Grant Funds, etc.): Estimated costs - $250K; Grants: CA Wildlife Conservation Board Streamflow Enhancement & Forest Restoration programs; Secure Rural Schools Title II Funds; other grant sources and fire emergency funds as available.

Timeline: 2026-2035 (focusing on a one- to two-year window post-fire)

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Plumas County PC Annex F-71
Local Hazard Mitigation Plan Update
January 2026
Project Priority (High, Medium, Low): High
Action 5. Red Clover Creek Watershed Floodplain Restoration Project Hazards Addressed: Ag Hazard: Severe Weather; Climate Change; Drought & Water Shortage (w/tree mortality; Flood (1%/0.2% annual chance and Localized Stormwater); Severe Weather: Extreme Heat, Heavy Rains and Storms; Wildfire (w/smoke and air quality) Issue/Background (Problem Statement): The 119 mi2 Red Clover Creek watershed is one of two large sub watersheds to Indian Creek. Indian Creek flows through Genesee and Indian valleys where flooding and channel instability are current hazards to the populace. Red Clover Valley contains more than 2,000 acres of restored floodplain, with ~2,000 additional acres in planning. The unrestored sections of Red Clover Creek, Dixie Creek, Crocker Creek and McReynolds Creek are severely downcut (incised).

Principal stressors were logging railroad grades built in the low gradient meadow in the 1930s & ‘40s, channel modification, livestock grazing, and roads. These incised channels capture all flows, rapidly draining out of the basin into the populated Genesee and Indian valleys downstream.

Loss of floodplain function and the rapid drainage of these headwater basins reduces the meadow’s ability to capture and store springtime snowmelt and rain as shallow groundwater. Sixty percent of California’s water supply originates in the Sierra Nevada, and meadows are a key component of that supply, helping to regulate water flow, temperature, and quality. As the headwaters of the State Water Project, the Feather River Watershed provides water to over 26 million Californians. Although wet meadows are less than one percent of the overall landscape in Plumas County, meadows’ unique hydrologic and ecological functions are recognized as being vital to watershed health and are valued for the ecosystem goods and services they provide, such as crucial habitat for many endemic and special status wildlife species. Known as biological diverse hot spots, healthy meadows provide refugia for wildlife during droughts and wildfire. Wet and moist meadows sequester carbon in the soil, where it isn’t susceptible to being lost in a wildfire. In addition, functioning meadow floodplains provide natural fire breaks reducing fire intensities and rate of spread.

From 2006 to 2022, 9 miles and 880 acres floodplain has been restored by Plumas Corporation, primarily on Plumas National Forest and Goodwin Family Ranch lands. The work restored the hydraulic base level of Red Clover and tributaries back to the historic meadow level, recovering crucial floodplain function.

The next project in the queue is McReynolds Valley, a 750-acre project currently in the design, CEQA/NEPA review and permitting phase. Implementation funding is being sought.

Project Description: The project is located on both private and public lands. The principal objective of the restoration work is to raise the hydraulic base level of the channel/floodplain system back to the historic meadow surface. This typically allows normal stream flows to access pre-existing remnant channels, while flood flows spread across the expansive floodplain surface. Longer residence times allows for enhanced infiltration to shallow and deeper groundwater basins, while filtering sediment and nutrients into the meadow ecosystem. This longer residence time in a functional floodplain reduces the pulse in flows downstream by allowing water to spread out and discharge downstream more slowly. Restoring floodplain function may be accomplished utilizing a variety of techniques, including complete and partial channel fill, raised riffles, and use of process-based channel structures (i.e., beaver dam analogs and post-assisted log structures), to name a few. Treatments would be specific to individual site conditions and constraints.

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Plumas County PC Annex F-72
Local Hazard Mitigation Plan Update
January 2026
Other Alternatives: none
Existing Planning Mechanism(s) through which Action Will Be Implemented: Feather River Watershed Strategy (2004), Upper Feather River Integrated Regional Water Management Plan (2016), Tributaries Forest Recovery Project Environmental Assessment & Decision Notice (2025), California State Water Action Plan (2014), Sierra Nevada Conservancy 2024-2029 Strategic Plan (2024) Responsible Office/Partners: Plumas Corporation Executive Director, Plumas National Forest, Plumas County, private landowners
Benefits (Losses Avoided): Reduction in flood stage in Genesee and Indian valleys, avoiding damage/loss to agricultural productivity, ranch/farm infrastructure, and residential homes; Reduction in sediment supply downstream, improving water quality for aquatic resources, recreation, and agricultural irrigation; Reduction in water temperatures, improving water quality for aquatic species and recreation; Increased surface water residence time extending surface water availability for wildlife and vegetation, and allowing for enhanced infiltration to shallow and deeper groundwater basins mitigating impacts from drought and water shortage, climate change, and wildfire.

Potential Funding (Local Budgets, Grant Funds, etc.): Estimated costs- $8,000,000. Grants- State grant programs via CA Wildlife Conservation Board and Sierra Nevada Conservancy; Plumas National Forest Dixie Fire funds; Corporate Investments- Microsoft, Coca-Cola, Disney, Proctor and Gamble, etc.

Timeline: 2026-2035
Project Priority (High, Medium, Low): High
Action 6. Tributaries Forest Recovery Project
Hazards Addressed: Ag Hazard: Severe Weather; Climate Change; Drought & Water Shortage (w/tree mortality; Flood (1%/0.2% annual chance and Localized Stormwater); Severe Weather: Extreme Heat, Heavy Rains and Storms; Wildfire (w/smoke and air quality) Goals Addressed: 1, 2, 3, 4, 5, 6
Issue/Background (Problem Statement): The Tributaries project encompasses a large portion of the major tributaries to Indian Creek. Indian Creek flows through Genesee and Indian valleys where flooding and channel instability are current hazards to the populace and agricultural operations. Over 60% of the Tributaries project area sustained high severity fire, with near complete loss of forest structure.

Additionally, many of the headwater streams within the project area lost all large wood and vegetative channel structure, resulting in repeated debris flows. These events were most notable in July 2020, October 2021 and June 2023, damaging or destroying County and Federal forest road infrastructure. These debris torrents are loading up the mainstem stream channels with sediments poised to be mobilized in the next major flood event, potentially impacting populated areas long after the “emergency” is over. Many of the degraded mainstem and headwater meadows were also severely impacted by fire severity, adversely affecting their ability to store and meter these sediments. 226 road crossings were surveyed in the

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Plumas County PC Annex F-73
Local Hazard Mitigation Plan Update
January 2026
Tributaries project area. 187 crossings were deemed to be at risk of failure, with further risk of damaging sediment loads released into the Indian Creek system.

Furthermore, to forestall the potential for the Feather River watershed to convert to a fire-dominated chaparral ecosystem, both reforestation and commercial/pre-commercial thinning of residual green stands are significant activities in the Tributaries project. Creating a more fire resilient forest structure will also mitigate flood, debris flow and drought conditions in the future.

Project Description: Plumas Corporation is the lead partner assisting the Plumas National Forest with planning and implementation of the 163,000-acre Tributaries Forest Recovery Project (Tributaries).

Tributaries is an all-hands, all-lands project to accelerate recovery of all forest values in the Dixie (2021) and Walker (2019) fire footprints. The proposed actions in the Tributaries project represent a suite of the following activities to replace lost forest conditions, while incorporating the predicted effects of climate change: conduct site preparation and conifer planting in strategic locations; improve the resilience of remaining green forest stands to future wildfire by fuel reduction and thinning from below; restore and enhance wildlife and botany with an emphasis on elk, California spotted owl (CSOW) and aquatic resources; identify, assess and develop treatments for road crossings that are impairing water quality, impacting downstream sediment supplies and/or are barriers to aquatic organism passage; develop restoration alternatives to restore meadow function for multiple benefits; and develop a suite of maintenance activities to ensure the investment in the recovery of forest values is sustained.

The project has completed CEQA review, with the NEPA process planned for completion by the end of the 2025 calendar year.

Other Alternatives: none
Existing Planning Mechanism(s) through which Action Will Be Implemented: Tributaries Forest Recovery Project Environmental Assessment & Decision Notice (2025), California’s Wildfire and Forest Resilience Action Plan (2021), USDA Forest Service Wildfire Crisis Strategy (2022), Feather River Watershed Strategy (2004), Upper Feather River Integrated Regional Water Management Plan (2016), California State Water Action Plan (2014), Sierra Nevada Conservancy 2024-2029 Strategic Plan (2024) Responsible Office/Partners: Plumas Corporation Executive Director, Plumas National Forest, Plumas County, Trout Unlimited, Maidu Summit Consortium
Benefits (Losses Avoided): Reduction in flood stage in Genesee and Indian valleys, avoiding damage/loss to agricultural productivity, ranch/farm infrastructure, and residential homes; Reduction in sediment supply downstream, improving water quality for aquatic resources, recreation, and agricultural irrigation; Reduction in water temperatures, improving water quality for aquatic species and recreation; Increased surface water residence time extending surface water availability for wildlife and vegetation, and allowing for enhanced infiltration to shallow and deeper groundwater basins mitigating impacts from drought and water shortage, climate change, and wildfire; Reduction in forest fuel loads, creating forest stands that are more resilient to wildfire and burn at lower intensity creating less smoke and reducing impacts on air quality.

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Plumas County PC Annex F-74
Local Hazard Mitigation Plan Update
January 2026
Potential Funding (Local Budgets, Grant Funds, etc.): Estimated costs- $125,000,000. Grants- State grant programs via CA Wildlife Conservation Board, Sierra Nevada Conservancy, and CalFire; Plumas National Forest Dixie Fire funds; Corporate Investments- Microsoft, Coca-Cola, Disney, Proctor and Gamble, etc.

Timeline: 2026-2035
Project Priority (High, Medium, Low): High
Action 7. Capacity Building to Transition to Sustainable Vegetation Management for Local Governmental Entities
Hazards Addressed: Wildfire
Goals Addressed: 1, 2, 3, 4, 5, 6
Issue/Background (Problem Statement): Plumas County faces significant wildfire risk due to overgrown forest conditions, drought-stressed vegetation, extensive tree mortality from bark beetle infestations, and the wildland-urban interface (WUI) where homes and infrastructure are adjacent to wildland fuels. In recent years, there has been intensified fire weather conditions, creating longer fire seasons and more extreme fire behavior. Dense forest conditions create dangerous fuel loads that threaten public safety, critical infrastructure, evacuation routes, and community assets. Without proactive hazardous fuels reduction, the county remains vulnerable to catastrophic wildfires that could result in loss of life, property damage, and environmental degradation.

The County of Plumas, City of Portola, and various special districts in Plumas County own parcels of land that require ongoing vegetation management in order to reduce the impact and spread of wildfire. These parcels tend to be located within or adjacent to residential neighborhoods, so proactive vegetation management is key to long-term risk management for the governmental entities and their communities.

However, these entities do not have the knowledge, experience, or capacity to perform vegetation management in the most cost-effective manner that is sustainable over a long period of time.

Project Description: This project involves Plumas Fire Safe Council working with local governmental entities to plan and implement vegetation management programs that allow for lower-cost long-term management to meet community safety and organizational objectives, as well as support the key risk priorities for wildfire that include protecting evacuation routes, maintaining defensible space around structures, maintaining critical infrastructure corridors, and developing strategic fuel breaks.

This project is essentially a method to build capacity across local government entities to plan and manage their own vegetation needs to meet organization and community protection goals. While a variety of management methods will always be needed, this project also seeks to build capacity for government entities to use prescribed fire. Prescribed fire remains one of the most ecologically effective and costefficient tools for reducing hazardous fuels, restoring fire-adapted ecosystems, and increasing landscape resilience across Plumas County. Implementation of prescribed burning must consider local conditions such as elevation, vegetation type, proximity to smoke-sensitive communities, and land ownership patterns.

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Portola City CouncilJune 10, 2026

Portola City Council
June 10, 2026