Initial Trends in Chemical Contamination, Toxicity and Land Use in California Watersheds: Stream Pollution Trends (SPoT) Monitoring Program

California State Water Resources Control Board (SWRCB) | April 1st, 2013

The State Water Resources Control Board’s Surface Water Ambient Monitoring Program (SWAMP) has released the second report on results from a continuing statewi

The State Water Resources Control Board’s Surface Water Ambient Monitoring Program (SWAMP) has released the second report on results from a continuing statewide program that measures trends in pollution levels and toxicity in major California watersheds. The program is called the Stream Pollution Trends monitoring program (SPoT), and it is one of three statewide projects funded by SWAMP. The report, Initial Trends in Chemical Contamination, Toxicity and Land Use in California Watersheds, summarizes results from the 2009–2010 annual SPoT surveys and represents an assessment of large watersheds across California to determine how stream pollutant concentrations are affected by land use, with an emphasis on urban and agricultural development. These data were compared to the 2008 SPoT sampling year, allowing a preliminary assessment of emerging trends. SPoT is improving our understanding of the long term trends of watershed contamination and associated toxicity. This program investigates the impacts of land development on water quality, helps prioritize water bodies in need of water quality management, and evaluates the effectiveness of management programs designed to improve stream health. SPoT forms the foundation for other regional programs and provides a statewide perspective so that local and regional water quality monitoring efforts can evaluate how conditions in their streams compare to those in other California watersheds.

Integrating Water and Land Management: A Suburban Case Study and Locally Adaptable Tool

California Department of Water Resources (DWR) | October 15th, 2013

Managing the impacts of development on water resources is an urgent challenge in California. To support more efficient growth with fewer environmental impacts, the Califo

Managing the impacts of development on water resources is an urgent challenge in California. To support more efficient growth with fewer environmental impacts, the California Legislature and governor have adopted policies to better integrate land use and resource management. The Land Use Planning and Management Resource Management Strategy (RMS) located within California’s 2009 Water Plan Update calls for Low Impact Development (LID) and Leadership in Energy and Environmental Design (LEED) development approaches to reduce land use impacts on water resources. These strategies are suggested to decrease indoor/outdoor or residential water consumption, improve the quality of stormwater runoff, decrease the quantity and flow rates of stormwater runoff, and protect downstream riparian habitat. The 2009 RMS set in motion a study to quantify costs and benefits associated with water-smart land use practices. Following this 2009 initiative, the charter for the RMS in the 2013 California Water Plan Update proposed a land use decision tool and demonstration of its application through pilot projects. For the first time since 1957, the Water Plan will also include a land use objective linked to corresponding actions. Consistent with this approach, the California Department of Water Resources partnered with Sonoma State University’s (SSU) Center for Sustainable Communities and conducted four case studies of suburban development in Sonoma County. An “Integrated Water and Land Management Tool” was also designed and built as part of this project. This tool may be downloaded free of charge at the website for the California Water Plan Update 2013. < http://www.waterplan.water.ca.gov/cwpu2013/index.cfm > Then navigate to Volume 4. Although existing tools are available to guide practitioners, those that are easy to use generally could not be modified to reflect local conditions. And calculators that could be modified possessed challenging user interfaces that required extensive background knowledge. Thus, the project team determined that a user-friendly calculator with the ability to customize and save local data would be a valuable asset. The case studies were then compared and contrasted using the new tool. This allowed users to specify different residential land cover and infrastructure choices and compare development outcomes, especially at the lot and neighborhood levels. Guiding principles for the study and creation of the tool were to: • Create an open, locally modifiable, and user-friendly tool to help guide land use and land cover decisions • Quantify relationships between land use alternatives and key water management benefits relating to water supply reliability, flood management, water quality, habitat value, and greenhouse gas emissions • Quantify the monetary costs of implementing LID and traditional development strategies, including long-term costs • Compare and contrast outputs from different development approaches, as exemplified in four case study sites This report, “Integrating Water and Land Management: A Suburban Case Study and Locally Adaptable Tool”, proceeds in two major parts: developing the tool, and then applying the tool to four residential developments in Sonoma County, California, as a proof of concept. While preliminary conclusions are made from the analysis of the case studies, the primary contribution of this research effort is a new, open-source Integrated Water and Land Management Tool, which will further grow and develop over time as additional case studies and applications are completed.

Land use and land cover influence on water quality in the last free-flowing river draining the western Sierra Nevada, California

Journal of Hydrology (Elsevier) | November 10th, 2005

Land use and land cover across 28 sub-basins within the Cosumnes Watershed, CA (1989 km2) were correlated to nitrate-N and total suspended solids (TSS) loading between w

Land use and land cover across 28 sub-basins within the Cosumnes Watershed, CA (1989 km2) were correlated to nitrate-N and total suspended solids (TSS) loading between water years 1999 and 2001. The impact of human development on stream water quality was evident as both agricultural area and population density predicted TSS loading in a linear mixed effects model. In contrast to the TSS model, the nitrate-N loading model was more complex with agriculture, grassland, and the presence or absence of waste water treatment plants (WWTPs) all contributing. The lack of correlation between population density and nitrate-N loading indicates that human habitation of the landscape does not impact stream nitrate levels until a WWTP is built within the sub-basin. During dry water years the models predict a linear reduction in TSS loading but the correlations to agriculture and population density remain positive. In contrast, nitrate is positively correlated to grasslands during average water years and negatively correlated during dry water years. Analysis of constituent fluxes from the upper watershed versus the lower watershed indicates that silica is derived primarily from the uplands and that during dry water years the upper watershed is an important source of dissolved organic carbon (DOC) and nitrate. The lower watershed contributes the majority of the sediment and nutrients during both dry and average water years, the one caveat being that during dry years the lower basin becomes a nitrate sink.

Land Use and Resource Management Plan for the Primary Zone of the Delta

Delta Protection Commission (DPC) | February 25th, 2010

The Delta Protection Act of 1992 (Act) established the Delta Protection Commission, a State entity to plan for and guide the conservation and enhancement of the natural r

The Delta Protection Act of 1992 (Act) established the Delta Protection Commission, a State entity to plan for and guide the conservation and enhancement of the natural resources of the Delta, while sustaining agriculture and meeting increased recreational demand. The Act defines a Primary Zone, which comprises the principal jurisdiction of the Delta Protection Commission. The Secondary Zone is the area outside the Primary Zone and within the “Legal Delta”; the Secondary Zone is not within the planning area of the Delta Protection Commission. The Act requires the Commission to prepare and adopt a Land Use and Resource Management Plan for the Primary Zone of the Delta, which must meet specific goals. This document constitutes the Land Use and Resource Management Plan for the Primary Zone of the Delta (Plan), as updated in 2010. The Act (Public Resources Code Section 29760 et. seq.) requires the Commission to prepare and adopt and thereafter review and maintain a comprehensive long-term Resource Management Plan for land uses within the Primary Zone of the Delta (“Resource Management Plan”). The Resource Management Plan is to set forth a description of the needs and goals for the Delta and a statement of the policies, standards, and elements of the Resource Management Plan. Within 180 days of the adoption of the Resource Management Plan or any amendments by the Commission, all local governments, as defined in Public Resources Code Section 29725, shall submit to the Commission proposed amendments to their general plans. The amendments shall cause the general plans to be consistent with the criteria in Public Resources Code Section 29763.5 with respect to land located within the Primary Zone. Those criteria include a requirement that the general plan be consistent with the Resource Management Plan (Plan).

Land Use and Water Quality on California’s Central Coast: Nutrient Levels in Coastal Waterways

University of California, Santa Cruz (UC Santa Cruz) | July 17th, 2003

Increased focus on addressing non-point source (NPS) pollution throughout the U.S. has raised awareness of agriculture’s impact on water quality. Growers are being a

Increased focus on addressing non-point source (NPS) pollution throughout the U.S. has raised awareness of agriculture’s impact on water quality. Growers are being asked to voluntarily limit the effects of their operations on adjacent waterways through programs such those initiated by county Farm Bureaus. If pollution cannot be voluntarily controlled, growers may face mandatory regulatory actions in the future. Maintaining water quality is an ongoing challenge in the Monterey Bay watershed, where industry, urban development, and farming all affect sensitive waterways. Excess nitrogen and phosphorous, herbicides, insecticides, and sediments that end up in sloughs and wetlands surrounding Monterey Bay have compromised water quality, contaminated shellfish, birds, and other wildlife, and generated unsafe levels of nitrate in drinking water.  Although nutrient contamination is well recognized, to date there have been few efforts to link water quality with land uses such as urban development and farming in the region. To determine the way that land uses affect nitrogen and phosphorous concentrations in central coast waterways, researchers Marc Los Huertos, Lowell Gentry, and Carol Shennan have monitored water flow and sampled water quality in the Pajaro River and in other Pajaro Valley and Elkhorn Slough watershed creeks and agricultural drainages, for the past two water years (October 2000–September 2002). The research takes place through the UC Santa Cruz Center for Agroecology and Sustainable Food Systems (the Center) and is part of a larger U.S. Department of Agriculture grant awarded to Center director Shennan. This water quality monitoring program was developed in cooperation with the Santa Cruz County Farm Bureau, local Resource Conservation Districts, and other groups.  We are particularly interested in the concentrations of two nutrients, nitrogen (nitrate-N) and phosphorus (ortho-P, also known as soluble reactive phosphorus), that are components of non-point source (NPS) pollution originating from urban and agricultural land uses.

Land Use Planning and Management (Resource Management Strategy)

California Department of Water Resources (DWR) | July 29th, 2016

Land use planning and management cuts across many resource management strategies (see Box 1). More efficient and effective land use is linked to several resource manageme

Land use planning and management cuts across many resource management strategies (see Box 1). More efficient and effective land use is linked to several resource management strategies including watershed, water use efficiency, groundwater quality, flood management, parks and recreation, climate change adaptive management, and agricultural lands stewardship. Directing development away from agricultural lands permits multi-objective management of these lands for agricultural preservation, floodplain management, water quality, habitat conservation, and sustainable development. In addition, planning for more compact and sustainable communities, both urban and rural, will assist in reducing reliance on the state’s water supply, and result in more efficient use of California’s water resources. Important considerations of water issues and land use planning include not only the effects of the physical environment, but also the economic and social impacts of land use planning and development. Stronger collaboration between land use planners and water managers can promote more efficient and effective land-use patterns and integrated regional water management (IRWM) practices, which can produce safer and more resilient communities. Integrating land use and water management consists of planning for the housing and economic development needs of a growing population, while providing for the efficient use of water, water quality, energy, and other resources. The way in which Californians use land — the type of land use, transportation, and level of use — has a direct relationship to water supply and quality, flood management, hazard mitigation, and other water issues. Likewise, the better integrated water resources are, the more efficient local communities can be at producing land use planning benefits and opportunities. For example, compact development patterns in existing urban areas can limit the amount of development in floodplains, leading to improved flood management and safety and more efficient infrastructure. Land use planners consider water throughout the local land use planning process, and water is a critical element in adopting efficient land use planning policies. The availability of water supplies, water resource features such as streams, wetlands, and groundwater recharge areas, and policies and regulations about water quality, drainage, and flooding are all considered for a community’s land use vision. Planners should also consider the benefits of integrating water- related features for flood management, water supply and quality, recreation, and climate change adaptive management.

Land Use, Pollutants, and Water Quality in California Streams

California State Water Resources Control Board (SWRCB) | April 12th, 2012

A number of spatial patterns were evident in this survey of watersheds from throughout California. Stream sediment concentrations of heavy metals, such as cadmi

A number of spatial patterns were evident in this survey of watersheds from throughout California. Stream sediment concentrations of heavy metals, such as cadmium, copper, lead and zinc, tended to be highest in urbanized Los Angeles and San Francisco Bay area watersheds. Metal concentrations in sediments from San Leandro Creek (SF Bay area), Ballona Creek and San Gabriel River (Los Angeles area) were among the highest in the state. These metals are released to the environment from brake pads, plumbing, industrial and commercial activities. Industrial organic compounds such as PCBs (banned since the 1970s), PBDEs (flame retardants) and PAHs (hydrocarbons) were also generally highest in stream sediments from the Los Angeles and San Francisco Bay areas, though high concentrations were also measured in some more remote locations. In contrast to this urban pattern, mercury concentrations were highest in sediments from watersheds where it is geologically abundant and historically mined, though some urban streams also had relatively high mercury levels. The persistent legacy pesticide DDT was found in stream sediments from most urban and agricultural watersheds, where recent soil disturbance from development and tillage likely mobilizes DDT residues from applications more than 40 years ago. Pyrethroid pesticides are increasing in use in California and were detected in 55% of the samples statewide (51 of 92). The highest pyrethroid concentrations were measured in sediments collected from urban watersheds, plus two agricultural watersheds along the central coast. Approximately one quarter of the sediment samples collected were significantly toxic to amphipods, which are resident crustaceans representative of important aquatic food web links. Of these samples, 6.5% were identified as highly toxic. The highly toxic samples were collected from agricultural watersheds in the Tulare basin and central coast, in urban areas of southern California, and in the Tijuana River. Other toxic samples were collected from a wide range of watershed types, including those along the north coast, the Tahoe area, and urban and agricultural areas across the state. On a statewide basis, watersheds with greater than 10% urban land cover had consistently higher sediment pollutant concentrations and toxicity than did watersheds characterized by agricultural or other land cover types. Metals, industrial compounds, DDTs, and pyrethroid pesticides were all found at significantly higher concentrations in urban streams. This pattern is evident at the statewide level, but other local and regional studies have previously shown that pollution levels and toxicity can be strongly related to agricultural and other land uses in specific areas. This is because the “agricultural” land use category used in the SPoT analysis is comprised of many different types of crops and farming practices, and the amount of polluted runoff from these lands varies depending on the types of practices employed.

Land Use/Water Supply Analysis Guidebook

Northern California Water Association | November 13th, 2008

The primary objective of the Land Use/ Water Supply Guidebook (Guidebook) is to provide members of the Northern California Water Association (NCWA) with practical inform

The primary objective of the Land Use/ Water Supply Guidebook (Guidebook) is to provide members of the Northern California Water Association (NCWA) with practical information to assist them with review or preparation of water supply and demand analyses as part of local land use planning processes. Through a broader understanding of the statutory requirements and relevant analytical methods, NCWA members can help ensure that Sacramento Valley land use planning efforts effectively consider water resources management issues. The Guidebook builds upon the successful efforts of the participants in the Sacramento Valley Integrated Regional Water Management Plan (IRWMP), which recognize that rapidly changing water use patterns in the Sacramento Valley are impacting business decisions. At the center of this change in Sacramento Valley water use patterns are the changes in land use in a historically agricultural region, driven primarily by urban development that is relying almost exclusively upon groundwater resources to meet new demands. Additionally, changing cropping patterns and managed wetlands may require additional water supplies. The Guidebook will highlight opportunities to maximize Sacramento Valley water resources and to avoid conflict by identifying the primary processes in California for linking water supply planning and land use planning at the local government level. The Guidebook focuses upon the water supply planning components in relevant land use planning documents, the assumptions used to develop the data and the conclusions, and considerations of the typical scope and depth of the required elements. By clearly identifying the range of reasonable assumptions, water managers, land use planners, special district board members, and local government staff and officials may effectively coordinate their efforts as part of the IRWMP and continue practicing integrated regional water management.

Land-use interactions, Oil-Field infrastructure, and natural processes control hydrocarbon and arsenic concentrations in groundwater, Poso Creek Oil Field, California, USA

Elsevier | May 7th, 2024

Landflex Grant Program Guidelines (revised)

California Department of Water Resources (DWR) | October 31st, 2024