Evaluating the Effects of Turf-Replacement Programs in Los Angeles County

University of California, Los Angeles (UCLA) | August 4th, 2017

In 2014, the Metropolitan Water District of Southern California (MWD) undertook an unprecedented investment to incentive turf replacement throughout Southern California i

In 2014, the Metropolitan Water District of Southern California (MWD) undertook an unprecedented investment to incentive turf replacement throughout Southern California in response to the state’s serious drought. MWD devoted $350 million to the program, resulting in more than 46,000 rebate payments to remove 165 million square feet of turf. The funding boost served as a tremendous natural experiment to better understand the effects turf replacement programs. As part of an evaluation of this program, UCLA and the University of Utah examined socio-economic and demographic characteristics of program participation and assessed changes in vegetation and landscapes of front yards resulting from turf replacement. We examined address-level records of 24,921 participants who applied for turf replacement rebates between February 2014 and April 2016 in Los Angeles (LA) County. We analyzed the socioeconomic and spatial determinants of program participation. Further, we used Google Earth Street View to characterize the landscapes and plants resulting from turf replacement based on a set of randomly selected participating properties. We ascertained the types of turf replacements that were installed and developed a classification system for landscape design types.

Evaluating the hydrologic effects of the 2021–2022 Scott and Shasta irrigation curtailments using remote sensing and streamflow gages

Klamath Tribal Water Quality Consortium | September 11th, 2023

Key Points • Satellite remote sensing data indicated that curtailment orders in 2022 reduced consumptive water use (evapotranspiration, ETa) on agricultural lands i

Key Points • Satellite remote sensing data indicated that curtailment orders in 2022 reduced consumptive water use (evapotranspiration, ETa) on agricultural lands in Shasta Valley, but not Scott Valley. • Streamflow gage data indicate that flows in the Shasta River and some Scott River tributaries (Shackleford and French creeks) were substantially higher in summer 2022 than 2020 or 2021, but similar increases did not occur in the mainstem Scott River. • A likely major reason for the lack of Scott River flow increases was that groundwater use was allowed to continue under Local Cooperative Solutions (LCS) agreements in which water users agreed to reduce pumping by 30% from a prior year baseline. Despite abundant worldwide evidence that reducing consumptive use (i.e., evapotranspiration) is key to increasing environmental water, all LCS cropping and irrigation practices were given equal weight toward the 30% reduction, regardless of the effects on consumptive use. Pumping was not measured and compliance was primarily self-reported, with limited independent verification.

Evapotranspiration of urban landscapes in Los Angeles, California at the municipal scale

American Geophysical Union (AGU) | May 24th, 2017

Evapotranspiration (ET), an essential process in biosphere-atmosphere interactions, is highly uncertain in cities that maintain cultivated and irrigated landscapes. We e

Evapotranspiration (ET), an essential process in biosphere-atmosphere interactions, is highly uncertain in cities that maintain cultivated and irrigated landscapes. We estimated ET of irrigated landscapes in Los Angeles by combining empirical models of turfgrass ET and tree transpiration derived from in situ measurements with previously developed remotely sensed estimates of vegetation cover and ground-based vegetation surveys. We modeled irrigated landscapes as a two-component system comprised of trees and turfgrass to assess annual and spatial patterns of ET. Annual ET from vegetated landscapes (ETveg) was 11106 53 mm/yr and ET from the whole city (vegetated and nonvegetated areas, ETland) was three times smaller, reflecting the fractional vegetation cover. With the exception of May and June, monthly ETland was significantly higher than predicted by the North American Land Data Assimilation System. ETveg  was close to potential ET, indicating abundant irrigation inputs. Monthly averaged ETveg varied from 1.560.1 mm/d (December) to 4.360.2 mm/d (June). Turfgrass was responsible for 70% of ETveg. For trees, angiosperm species (71% of all trees) contributed over 90% to total tree transpiration, while coniferous and palm species made very small contributions. ETland was linearly correlated with median household income across the city, confirming the importance of social factors in determining spatial distribution of urban vegetation. These estimates have important implications for constraining the municipal water budget of Los Angeles and improving regional-scale hydrologic models, as well as for developing water-saving practices. The methodology used in this study is also transferable to other semiarid regions for quantification of urban landscape ET.

Exploring the Potential for Water-Limited Agriculture in the San Joaquin Valley

Public Policy Institute of California (PPIC) | July 21st, 2022

The rollout of California’s Sustainable Groundwater Management Act (SGMA) is altering the state’s agricultural landscape. As groundwater sustainability measures are

The rollout of California’s Sustainable Groundwater Management Act (SGMA) is altering the state’s agricultural landscape. As groundwater sustainability measures are implemented and water scarcity increases, at least half a million acres are projected to come out of irrigated production in the San Joaquin Valley, the state’s agricultural heartland. Rather than widespread land idling—which comes with unintended consequences such as dust, weeds, pests, and soil degradation — a switch from summer irrigated crops to winter crops produced with limited water (including winter cereals and forage crops, among others) might keep some of this land in production. Although water-limited agriculture faces large hurdles, some promising aspects warrant further exploration.

Field-scale crop water consumption estimates reveal potential water savings in California agriculture

Nature Portfolio (Springer Nature) | March 25th, 2024

Freshwater Scarcity

Annual Review of Environment and Resources (Annual Reviews) | October 24th, 2021

The availability and use of fresh water are critical for human health and for economic and ecosystem stability. But the growing mismatch between human demands and natur

The availability and use of fresh water are critical for human health and for economic and ecosystem stability. But the growing mismatch between human demands and natural freshwater availability is contributing to water scarcity, affecting industrial and agricultural production and a wide range of social, economic, and political problems, including poverty, deterioration of ecosystem health, and violent conflicts. Understanding and addressing different forms of water scarcity are vital for moving toward more sustainable management and use of fresh water. We provide here a review of concepts and definitions of water scarcity, metrics and indicators used to evaluate scarcity together with strategies for addressing and reducing the adverse consequences of water scarcity, including the development of alternative sources of water, improvements in water-use efficiency, and changes in systems of water management and planning.

From wastewater treatment plants to decentralized resource factories

Nature Portfolio (Springer Nature) | June 10th, 2024

Funding Opportunity for Voluntary Participation in the Lower Colorado Conservation and Efficiency Program

U.S. Bureau of Reclamation (USBR) | October 12th, 2022

Future land-use related water demand in California

Environmental Research Letters (IOP) | May 18th, 2019

Water shortages in California are a growing concern amidst ongoing drought, earlier spring snowmelt, projected future climate warming, and currently mandated water use r

Water shortages in California are a growing concern amidst ongoing drought, earlier spring snowmelt, projected future climate warming, and currently mandated water use restrictions. Increases in population and land use in coming decades will place additional pressure on already limited available water supplies. We used a state-and-transition simulation model to project future changes in developed (municipal and industrial) and agricultural land use to estimate associated water use demand from 2012 to 2062. Under current efficiency rates, total water use was projected to increase 1.8 billion cubic meters (+4.1%) driven primarily by urbanization and shifts to more water intensive crops. Only if currently mandated 25% reductions in municipal water use are continuously implemented would water demand in 2062 balance to water use levels in 2012. This is the first modeling effort of its kind to examine regional land-use related water demand incorporating historical trends of both developed and agricultural land uses.

GreenPlan-IT Tracker

San Francisco Estuary Institute (SFEI) | June 14th, 2018

This technical memo describes the purpose, functions, and structure associated with the newest addition to the GreenPlan-IT Toolset, the GreenPlan-IT Tracker. It also sh

This technical memo describes the purpose, functions, and structure associated with the newest addition to the GreenPlan-IT Toolset, the GreenPlan-IT Tracker. It also shares the opportunities for further enhancement and how the tool can operate in concert with existing resources. Furthermore, this memo describes a licensing plan that would permit municipalities to use the tool in an ongoing way that scales to their needs. The memo concludes with a provisional roadmap for the development of future features and technical details describing the tool’s platform and data structures. About the GreenPlan-IT Toolkit Municipalities across the state and beyond are carefully planning and implementing green infrastructure in their developed landscape to restore key aspects of the natural water cycle. Green infrastructure helps to achieve stormwater attenuation and contaminant filtration by increasing the pervious surfaces in often sophisticated ways. Additionally, green infrastructure features, as city dwellers have come to realize, demonstrate multiple benefits in addition to improving surface porosity, such as peak, volume, and load reductions, urban heat island mitigation, traffic calming, carbon sequestration, wildlife habitat, natural aesthetics, and others. The benefits are substantial, but so are the potential costs. GreenPlan-IT helps planners to make smart decisions in the types and locations of green infrastructure, minimizing effort and cost while maximizing the effectiveness of the public and private investments. GreenPlan-IT modules are focused on green infrastructure planning and assessment, including the Site Locator Tool, Modeler, and Optimizer tools. Together the modular toolkit can be used to take a city from a position of not knowing where to consider GI placement (a daunting position given the MRP C3 and C11/12 requirements), to a plan that includes a list and map of feasible locations and a map of baseline flow and pollutant load conditions, and a selected optimal set of placement locations for achieving flow and load reductions at minimal cost. Now, with the advent of the GreenPlan-IT Tracker, there is also a web based tracker for quantifying and communicating the locations, types, and treatment areas of GI installations (the outputs of all the planning efforts) and quantifying the peak flows, volumes, and loads reduced (the outcomes of all the implementation and cost expenditure that the community is asking for).