Santa Margarita River study examining how to develop ‘climate-ready’ eutrophication targets

SCCWRP and its partners have begun investigating how climate change could influence efforts to reduce eutrophication in the Santa Margarita River watershed, part of a five-year study exploring how to set nutrient loading targets to protect the watershed’s ecological health.

During the investigation, which was launched in October, researchers will develop targets for reducing nutrient inputs that take into account how climate change is predicted to alter temperature and flow patterns in the watershed.

The goal is to show how appropriate safety margins can be built into nutrient loading targets to ensure eutrophication management strategies are “climate-ready.”

Over the past few years, researchers have built an integrated toolkit of mechanistic computer models and empirical statistical models for setting scientifically defensible nutrient loading targets.

The models are now being expanded to simulate how flow, nutrients and temperature influence algal blooms and dissolved oxygen levels. The models will be used in tandem with regional flow ecology models to understand impacts to aquatic life.

The Santa Margarita River watershed, which spans Riverside and northern San Diego Counties, is serving as a key California case study for test-driving technical elements of a proposed State Water Board biointegrity-biostimulatory policy to govern the health of wadeable streams statewide.