Large Landscape Urban Irrigation: A Data‐Driven Approach to Evaluate Conservation Behavior

American Geophysical Union (AGU) | April 30th, 2019

Do businesses, multifamily residences, and homeowners associations irrigate differently than single‐family residences? Do customers who have recycled water irrigate di

Do businesses, multifamily residences, and homeowners associations irrigate differently than single‐family residences? Do customers who have recycled water irrigate differently than if they have potable water? How does water use change during drought and under different policy regimes? Is neighborhood affluence related to conservation behavior by nonresidential irrigation customers? These questions are all important for water managers planning how much water they need when and where, in the present and in the future. In this paper, we statistically investigated and modeled water use in a case study service area to examine how water demand for nonresidential large landscapes changed during a historic drought. The findings of this paper can help water managers understand urban water use behavior, which is useful for supply planning, targeting conservation efforts, and optimizing infrastructure investment.

Large Landscape Urban Irrigation: A Data‐Driven Approach to Evaluate Conservation Behavior

American Geophysical Union (AGU) | January 30th, 2019

Do businesses, multifamily residences, and homeowners associations irrigate differently than single‐family residences? Do customers who have recycled water irrigate di

Do businesses, multifamily residences, and homeowners associations irrigate differently than single‐family residences? Do customers who have recycled water irrigate differently than if they have potable water? How does water use change during drought and under different policy regimes? Is neighborhood affluence related to conservation behavior by nonresidential irrigation customers? These questions are all important for water managers planning how much water they need when and where, in the present and in the future. In this paper, we statistically investigated and modeled water use in a case study service area to examine how water demand for nonresidential large landscapes changed during a historic drought. The findings of this paper can help water managers understand urban water use behavior, which is useful for supply planning, targeting conservation efforts, and optimizing infrastructure investment.

Lessons from Immersive Online Collaborative Modeling to Discuss More Adaptive Reservoir Operations

American Society of Civil Engineers (ASCE) | April 26th, 2024

Linkages between land-use change and groundwater management foster long-term resilience of water supply in California

Journal of Hydrology: Regional Studies (Elsevier) | March 9th, 2022

Study Region: We created a 270-m coupled model of land-use and groundwater conditions, LUCAS-W[ater], for California’s Central Coast. This groundwater-dependent region

Study Region: We created a 270-m coupled model of land-use and groundwater conditions, LUCAS-W[ater], for California’s Central Coast. This groundwater-dependent region is undergoing a dramatic reorganization of groundwater management under California’s 2014 Sustainable Groundwater Management Act (SGMA). Study Focus: Understanding land-use and land-cover change supports long-term sustainable water management. Anthropogenic water demand has depleted groundwater aquifers worldwide, while future water shortages will likely affect land-use change, creating system feedbacks. Our novel participatory approach fused changes in land-use and associated water use from county-scale data to local water agencies’ estimates of total sustainable supply, scaling up local hydro-geologic knowledge from heterogeneous aquifers and diverse management approaches to a regional level. We assessed five stakeholder-driven scenarios with the same historic rates of urban and agricultural land-use change, but different water and land-use management, analyzing how management strategies altered both the spatial pattern of development and subsequent water sustainability from 2001 to 2061. New Hydrological Insights for the Region: Transformative strategies using demand-side interventions that coupled water availability to land use more effectively achieved long-term sustainability than adaptive strategies using supply-side interventions to increase water supplies. Limiting water withdrawals within SGMA regulated basins resulted in leakage of development into unregulated basins, increasing groundwater pumping there. Protecting ecosystems, farmlands, and recharge areas from development reduced leakage into undeveloped basins without negatively affecting water sustainability.

Linking river management to species conservation using dynamic landscape-scale models

River Research and Applications (Wiley) | March 23rd, 2012

Efforts to conserve stream and river biota could benefit from tools that allow managers to evaluate landscape-scale changes in species distributions in response to water

Efforts to conserve stream and river biota could benefit from tools that allow managers to evaluate landscape-scale changes in species distributions in response to water management decisions. We present a framework and methods for integrating hydrology, geographic context and metapopulation processes to simulate effects of changes in streamflow on fish occupancy dynamics across a landscape of interconnected stream segments. We illustrate this approach using a 482 km2 catchment in the southeastern US supporting 50 or more stream fish species. A spatially distributed, deterministic and physically based hydrologic model is used to simulate daily streamflow for sub-basins composing the catchment. We use geographic data to characterize stream segments with respect to channel size, confinement, position and connectedness within the stream network. Simulated streamflow dynamics are then applied to model fish metapopulation dynamics in stream segments, using hypothesized effects of streamflow magnitude and variability on population processes, conditioned by channel characteristics. The resulting time series simulate spatially explicit, annual changes in species occurrences or assemblage metrics (e.g. species richness) across the catchment as outcomes of management scenarios. Sensitivity analyses using alternative, plausible links between streamflow components and metapopulation processes, or allowing for alternative modes of fish dispersal, demonstrate large effects of ecological uncertainty on model outcomes and highlight needed research and monitoring. Nonetheless, with uncertainties explicitly acknowledged, dynamic, landscape-scale simulations may prove useful for quantitatively comparing river management alternatives with respect to species conservation.

Local and synoptic mechanisms causing Southern California’s Santa Ana winds

Climate Dynamics (Springer) | August 25th, 2009

The cool, moist fall and winter climate in Southern Cali- fornia is often disrupted by dry, hot days with strong winds blowing out of the desert. These ‘‘Santa Ana’

The cool, moist fall and winter climate in Southern Cali- fornia is often disrupted by dry, hot days with strong winds blowing out of the desert. These ‘‘Santa Ana’’ winds are a dominant feature of the fall and wintertime climate of Southern California (Conil and Hall 2006), and have important human and ecological impacts. First, and most pronounced, is their effect on wildfires: following the hot, dry summer, the extremely low relative humidities and gusty strong winds that occur during Santa Anas introduce extreme fire risk which often culminates in wildfires with large economic loss.

Los Angeles Basin Stormwater Conservation Study: Task 3.1 Climate Change and Hydrologic Projections Appendices

U.S. Bureau of Reclamation (USBR) | October 1st, 2013

Reclamation’s Technical Service Center (TSC) performed Task 3.1 of the LA Basin Study—to develop and evaluate projected future climate conditions related to precipita

Reclamation’s Technical Service Center (TSC) performed Task 3.1 of the LA Basin Study—to develop and evaluate projected future climate conditions related to precipitation frequency over the Los Angeles Basin. The subtasks were to: Consider existing projections of climate change in the LA Basin Study area Determine appropriate climate scenarios for use in developing precipitation and potential evaporation input datasets to support subsequent hydrologic modeling Prepare data (hourly precipitation and potential evaporation) for input into the LACFCD’s Watershed Management Modeling System (WMMS) Determine storm event frequency for planning purposes The data, methods, and results from Task 3.1 are documented in this report. Results from these four subtasks were then transmitted to LACFCD, who used these results as input in their WWMMS as part of Task 3.2 of the LA Basin Study. LACFCD is preparing a companion report with the results from the hydrologic modeling.

Los Angeles Basin Stormwater Conservation Study: Task 3.2 Hydrologic Modeling Report

U.S. Bureau of Reclamation (USBR) | December 3rd, 2013

The Los Angeles County Flood Control District (LACFCD) partnered with the U.S. Department of the Interior, Bureau of Reclamation (Reclamation) to collaborate on t

The Los Angeles County Flood Control District (LACFCD) partnered with the U.S. Department of the Interior, Bureau of Reclamation (Reclamation) to collaborate on the Los Angeles Basin Stormwater Conservation Study (LA Basin Study). The purpose of the LA Basin Study is to investigate long-range water conservation and flood control impacts caused by projected changes in climate conditions and population in the Los Angeles region. The LA Basin Study will recommend potential modifications or changes in the operation of the existing stormwater capture systems, and the development of new facilities that could help resolve future water supply and flood control issues. These recommendations will be developed by identifying alternatives and conducting trade-off analyses. For Task 3, Downscaled Climate Change and Hydrologic Modeling of the LA Basin Study, Reclamation developed downscaled climate change projections, while LACFCD applied these projections to generate the future hydrology. LACFCD utilized the Watershed Management Modeling System (WMMS) to perform the hydrologic modeling for the LA Basin Study. This report summarizes the data, methods, and results of the historic and future hydrologic modeling. The purpose of Task 3.2, Hydrologic Modeling is to simulate hydrology with respect to climate change for the Los Angeles River, San Gabriel River, Ballona Creek, South Santa Monica Bay, North Santa Monica Bay, Malibu Creek, and Dominguez Channel/Los Angeles Harbor watersheds (Basin Study Watersheds). This study incorporates the entire watershed boundaries, including where they extend outside of Los Angeles County. The following sub-tasks were identified to achieve this objective: Historic Hydrologic Modeling (Water Year 1987 through 2000) Determine baseline scenario modeling assumptions Prepare WMMS to simulate baseline scenario Perform WMMS baseline simulations Analyze and summarize WMMS results Projected Hydrologic Modeling (Water Year 2012 through 2095) Determine future scenario modeling assumptions Prepare WMMS to simulate future scenarios Perform WMMS simulations Analyze and summarize WMMS results

Los Angeles Basin Stormwater Conservation Study: Task 5 Infrastructure & Operations Concepts Report

U.S. Bureau of Reclamation (USBR) | December 1st, 2015

The Los Angeles Basin Stormwater Conservation Study (LA Basin Study) is a collaborative partnership between the Los Angeles County Flood Control District (LACFCD) and the

The Los Angeles Basin Stormwater Conservation Study (LA Basin Study) is a collaborative partnership between the Los Angeles County Flood Control District (LACFCD) and the U.S. Department of the Interior, Bureau of Reclamation (Reclamation). The purpose of the LA Basin Study is to investigate long-range water conservation and flood risk management impacts caused by projected changes in the climate and population in the Los Angeles region. The LA Basin Study provides recommendations for potential modifications and changes to the existing regional stormwater capture system, as well as for the development of new facilities and practices, which could help to resolve future water supply and flood risk management issues. The stormwater capture concepts and alternatives developed within this report will inform the Task 6 – Trade-Off Analysis & Opportunities report of the LA Basin Study.  The objective of Task 5, Infrastructure and Operations Concepts, is to identify and develop both structural and nonstructural (i.e., plans and policies) concepts to manage stormwater under projected climate conditions for the Los Angeles Basin watersheds, which include: Los Angeles River, San Gabriel River, South Santa Monica Bay, North Santa Monica Bay, Ballona Creek, Malibu Creek, and Dominguez Channel/Los Angeles Harbor watersheds (Basin Study Watersheds). The efforts and results previously completed for Task 2 – Water Supply & Water Demand Projections, Task 3 – Downscaled Climate Change & Hydrologic Modeling, and Task 4 – Existing Infrastructure Response & Operations Guidelines Analysis serve as the foundation for Task 5. The major tasks and subtasks of Task 5 include:  Concept Development  - Identify a range of opportunities and options using stakeholder input  - Determine preliminary concepts for further evaluation  Technical Analysis of Concepts  - Assess structural and nonstructural concepts pertaining to dams, spreading grounds, flood control channels, decentralized storage, infiltration, reuse facilities, debris basins, and other concepts  - Develop and apply concept selection criteria  Appraisal-Level Analysis  - Evaluate selected concepts for future system reliability, efficiency, and effectiveness  In addition to any new stormwater conservation concepts that are developed, the existing facilities from the Task 4 analysis were considered for enhancement. The Watershed Management Modeling System (WMMS), which has served as the primary hydrologic model throughout the LA Basin Study, continued to be the preferred tool and was also used for Task 5. Hydrologic simulations were conducted to analyze the potential water conservation and flood risk mitigation benefit for the various project concepts. For the future period, water years 2012 through 2095, four climate projections (Low 1, Low 2, Mid 2, and High 1) from Task 4 were used in the simulations.  Click here for USBR's Task 5 Appendices index: Appendix A - Infrastructure and Operations Concepts (Excel) Appendix B - Local Stormwater Capture (PDF)  Appendix C - Modeling Approach and Solutions (PDF) Appendix D - Local Management Cost (Excel) Appendix D - Regional 1 Cost (Excel) Appendix D - Regional 2 Cost (Excel) Appendix D - Regional 3 Cost (Excel) Appendix D - Storage 3 Cost (Excel) Appendix E - LACFCD Dam Hydrology and Cost Estimates (PDF)

Los Angeles County Department of Public Works Hydrology Manual

Los Angeles County Department of Public Works (LACDPW) | January 30th, 2006

This manual establishes the Los Angeles County Department of Public Works' hydrologic design procedures and serves as a reference and training guide. This manual contains

This manual establishes the Los Angeles County Department of Public Works' hydrologic design procedures and serves as a reference and training guide. This manual contains charts, graphs, and tables necessary to conduct a hydrologic study within the County of Los Angeles. Examples provide guidance on using the hydrologic methods.