Introduction
Using data to track the health of California’s Delta is critical to achieving a reliable statewide water supply and a resilient ecosystem that protects and enhances the Delta as a place where people live, work, and recreate. It is essential that environmental managers and scientists that work in the Delta are informed about the Delta Plan’s performance measure changes annually to:
- Ensure that environmental decision-making is based on the best available science and
- Evaluate the overall effectiveness of Delta Plan implementation.
Changes over multiple years that indicate significant trends could lead to potential amendments to state policy, the Delta Plan, and on-the-ground management approaches. This web page aims to communicate the yearly progress of performance measures.
The performance measures featured in the collapsible accordion bars below reflect the changing conditions that scientists observed throughout the 2022 water year. More information about each can be found on their respective web pages. In addition, these 2022 performance measure updates were presented at the January 2023 Council meeting (see agenda item 8), and a subset is showcased in the Council's 2022 Annual Report.
In 2022, the Council reached a significant milestone toward strengthening the Delta’s ecosystem and restoration efforts. In June, the Council adopted revisions to Chapter 4 of the Delta Plan, also known as the ecosystem chapter. This adoption introduced new and revised performance measures for tracking the health of the Delta’s ecosystem, which are now part of this dashboard.
2022 Conditions
In 2022, California continued to experience dry conditions with lower-than-average precipitation and stream flow. In addition, January and February 2022 were two of the driest months on record. As a result, Delta ecosystem and water quality conditions in 2022 reflect the impacts of another consecutive drought year. Multi-year drought conditions also impacted the availability of Delta water supplies.
Performance Measure Spotlights
Why measure Urban Water Use?
Monitoring water supply performance metrics is critical to water conservation and drought preparedness. The Council’s urban water use measure tracks gallons per capita per day targets set by water suppliers who prepare and adopt urban water management plans (UWMPs). 2022 was a dry year in California and the third year of a statewide drought. Because of these conditions, water conservation is more important than ever.
What happened in 2022?
UWMPs were submitted to the California Department of Water Resources (DWR). In 2022, DWR collected and reviewed most of the UWMPs for completeness. Those plans are posted on their data portal. In addition to data in the projects, the State Water Resources Control Board has been tracking California residential water use per capita.
Why is this important?
UWMPs are a tool California’s urban water suppliers use to plan how they will meet user demand for water over the long term. The data in these plans will help inform progress on supporting long-term water conservation actions in California’s urban areas.
What steps are being taken in 2023?
This measure will be updated with data from the UWMPs in 2023 when DWR completes its reviews of the UWMPs submitted in 2022. This data will be able to inform forward-looking projections on longer-term trends in urban water use. The 2022-2023 water year has begun wet, giving some relief from the ongoing drought. Even with this relief, long-term planning to support urban water use conservation remains a priority. Urban water conservation will help keep the water supply reliable and affordable for California’s residents.
For more details, visit the Urban Water Use performance measure.
Why measure flows?
Measuring flows is vital since the water flow is a critical indicator of the aquatic habitat. The flow impacts water temperature, dissolved oxygen, turbidity, and other physical components of the ecosystem. Thus, flow levels influence the health of native species and their habitat. Measuring flows monitor the health of the ecosystem.
What happened in 2022?
2022 was another dry year, the third consecutive dry year, so flow targets still needed to be met due to low flows.
Why is this important?
Restoring to a healthier estuary requires using more natural functional flows – including in-Delta flows and tributary input flows – to support ecological floodplain processes like floodplain inundation, peak flows, recession flows, and in-Delta flows.
What steps are being taken in 2023?
The Big Notch Project to Fremont Weir is planned to finish construction in the fall of 2023, which will help increase Yolo Bypass inundation, thus making target 4.2a more reachable.
For more details, visit the Yolo Bypass Inundation performance measure.
Why measure farmland loss?
Measuring farmland loss in the Delta is important because reductions in Delta farmland affect businesses, jobs, and many Delta communities. In addition, cultivated farmland is critical to the Delta agricultural economy, and preserving it will promote the community and small family farms and retain the Delta rural heritage.
What happened in 2022?
In 2022, Farmland Mapping and Morning Program (FMMP) data from 2018 became available and was analyzed for the conversion of farmland in the Delta from 2014 to 2018. Since 2014 there has been an overall farmland loss of 12,386 acres. Of the overall loss, around 2,150 acres were lost to urban development. Furthermore, from 2016 to 2018, farmland decreased by about 8,985 acres, of which only 1,067 were converted to urban development. Conversions in 2022 under the General Plan land designation also showed no changes in farmland designated for urban development.
Why is this important?
Reductions in Delta farmland affect businesses, jobs, and many Delta communities. Conversely, preserving farmland promotes community and small family farms and retains the Delta’s rural heritage.
The 2022 farmland data analysis during the 2016-2018 period, and overall, is critical because it shows that most farmland conversions were outside of urban development. And that farmland decline to urban development has slowed.
What steps are being taken in 2023?
Continue to track and review farmland conversion to potential urban development. The Department of Conservation is also processing remotely sensed data to update the 2020 FMMP. The release date for the 2020 data is expected by 2024.
For more details, visit the Farmland Loss Performance Measure.
Why measure Delta Tourism?
The Delta is a world-class tourism destination and offers diverse boating, fishing, recreation, and cultural and agricultural tourism opportunities. It was designated as a National Heritage Area in 2019 by the United States Congress. The Delta Tourism performance measure consists of seven recreation-related metrics, including fishing license sales data and data about tourist-related social media and web traffic.
What happened in 2022?
We updated fishing license and web traffic data for 2020 and 2021. The trend of fishing license sales in Delta counties has been positive. In 2020 and 2021, sales of fishing licenses increased, reversing a general long-term slowing trend in fishing license sales.
Web traffic to VisitCADelta, the region’s primary web resource for promoting the Delta, has seen steady growth. This resource encourages events, businesses, and amenities in the Delta for tourists to enjoy. Web traffic in 2020 increased by 72% from the previous year, and in 2021 the growth continued with a 28% increase from a year earlier. In 2021, over 100,000 people used the website, demonstrating the increased value of the web presence to the region’s recreational economy.
Why is this important?
2020 and 2021 were two of the most challenging years for tourism because of the Covid-19 pandemic. Yet, despite these challenges, the Delta region demonstrated resilience. Fishing license sales went up as people looked for safe outdoor recreation activity, and the web resources to support tourism in the area were more widely used than ever.
What steps are being taken in 2023?
In 2019, Congress passed, and the president signed a law declaring the Delta region a National Heritage Area. The Delta protection commission continues to work toward producing the plan for the region to guide investment in the region to support cultural tourism. Additionally, 2022 saw the completion of the Great California Delta Trail Master Plan. 2023 will bring the first efforts to implement that plan in the Delta region. Implementation will provide more trails, improved trails, and increased communication about the available outdoor recreation opportunities in the Delta.
For more details, visit the The Delta Tourism performance measure
Why measure Delta Water Quality?
High amounts of pollutants, or other water quality issues, can impair the ability of water to support beneficial uses, such as recreational use, agricultural water supply, municipal water supply, and healthy habitat for native vegetation and wildlife. Therefore, reducing impaired water bodies on the 303(d) list of the Clean Water Act is essential for protecting beneficial uses in the Delta. The Council’s water quality performance measure (PM 6.01) tracks the total number of impaired waterbodies and the contaminants (waterbody contaminant combinations) prevalent within the Delta and Suisun Marsh on the 303(d)-list section (list) within the California Clean Water Act’s Integrated Report.
What happened in 2022?
In 2022, the list was updated and showed a 30 percent net increase in waterbody contaminant combinations. The significant pollutants added to the list included pesticides, dissolved solids, nutrients, and metals.
Why is this important?
An increase in waterbody contaminant combinations means water quality in the Delta is declining. Since 2010 (baseline), there has been a 43% net increase in waterbody contaminant combinations. A continual rise in waterbody contaminant combinations is detrimental to beneficial uses.
What steps are being taken in 2023?
Several ongoing and future projects, plans, and programs are tackling water quality impairments in the Delta and Suisun Marsh. Several of these efforts are tracked in the Council’s administrative performance measures. These include:
- Central Valley Salinity Alternatives for Long-Term Sustainability Program,
- Dissolved Oxygen Total Maximum Daily Load for Stockton Deep Water Ship Channel and Suisun Marsh,
- Methylmercury studies,
- Mercury Total Maximum Daily Load.
For more details, visit the Delta Water Quality performance measure.
Why measure salinity?
As Pacific Ocean saltwater flows into Delta freshwater, salinity levels change in the Delta. If too much saltwater enters the Delta, it can reduce the quality of the water used for agricultural and municipal purposes and harm native species. Drought conditions exacerbate salinity conditions by reducing freshwater river flows into the Delta. Compliance stations are set up around the Delta to monitor and report salinity levels.
What happened in 2022?
In 2022, Delta salinity levels showed compliance exceedances for only one compliance station in the south Delta for agricultural objectives. This means the salinity levels could have negatively affected farm irrigation water during that period of exceedance. In addition, the exceedances occurred during the winter and spring months.
Why is this important?
Although drought conditions continued in 2022, only one station exceeded compliance compared to four stations in 2021. Like in 2021, 2022 had a Temporary Urgency Change Petition (TUCP) between April and June, allowing operational flexibility in meeting salinity objectives.
Even with the compliance objectives being met, continued drought conditions in 2022 reduced the amount of freshwater that entered the Delta, which allowed salinity to migrate further into the Delta. This negatively affected the farmers who rely on and use Delta water because increased salinity in the water used for crops reduces crop yields and increases soil salinity. In addition, although compliance stations met salinity standards for ecosystem objectives, reduced freshwater flow negatively impacted native fish species by reducing ideal habitat space, which requires a certain amount of freshwater flow.
What steps are being taken in 2023?
In response to the continuing drought, the emergency drought proclamation has been extended until January 2024.
For more details, visit the Salinity performance measure.
Why measure HABs?
The impacts and threats of HABs on water quality and public health in the Delta are becoming increasingly frequent and severe. The region’s unique location near major cities and agricultural hubs and its low-flowing and winding channels in a warm Mediterranean climate present environmental conditions conducive to HABs.
HABs are caused by environmental factors such as:
- nutrient levels,
- water flow and chemistry,
- algal species composition, and
- temperature and sunlight exposure.
These factors may be exacerbated by human activities (such as pollution), the presence of invasive species, and reduced freshwater flows. In addition, under climate change-driven drought conditions, the Delta may continue to experience more frequent and severe HABs.
What happened in 2022?
In 2022, HAB incidents reported increased to 60 compared to 46 the previous year. This dramatic year-over-year increase may be due to drought conditions and/or increased monitoring and reporting by State and local agencies and community-based organizations.
Most HABs incidents occur during summer in populated areas. As a result, most were assigned cautionary advisory levels, meaning harmful algae may be present. Still, a few were labeled as dangerous, which means that toxins from algae in the water can harm people and animals.
In response, the Delta Science Program hosted a Delta Harmful Algal Blooms Workshop in November to help inform a science-based HABs monitoring strategy. A HABs monitoring strategy for the Delta will be beneficial for protecting public health and developing a plan to mitigate HABs.
Why is this important?
When HABs occur, they can harm humans, wildlife, and domestic animals that encounter or ingest water from the affected water body. Direct human health impacts can range from minor rashes to liver and kidney harm and neurological system damage. In addition, HABs can be lethal for wildlife and pets.
The increase in HABs incidences may also be a positive sign of the increased monitoring and data sharing within the Delta. More monitoring in the Delta leads to more awareness of HABs, which can lead to fewer harmful public health incidents.
What steps are being taken in 2023?
A monitoring strategy for the Delta will help mitigate the effects of HABs on water quality and public health as a result of the Delta HABs Workshop.
Additionally, incident reports will continue to be tracked by the California Cyanobacteria and HAB Network and State Water Resources Control Board HABs incident reporting tool. Local agencies (for example, East Bay Parks) may also be tracking HABs on their respective websites.
For more details, visit the Harmful Algal Blooms performance measure.