For Denise Duffy & Associates and the City of San José
San José, California

Questa completed water quality field studies and feasibility analysis for Lake Cunningham, a 50-acre recreational lake at the center of Lake Cunningham Regional Park in San José, CA. The lake had experienced significant water quality problems, largely associated with summer freshwater harmful algal blooms (FHABs) and poor water circulation. These problems resulted in permanent closure of the lake to water contact recreation and impacts to aquatic life, including occasional fish kills. Questa evaluated existing water quality conditions, identified the main causes of water quality degradation, and provided recommended alternatives for improving dissolved oxygen (DO) levels, reducing FHABs, and expanding recreational opportunities at the lake to include swimming and other full contact water sports. Work included investigation of land use and management actions using aerial photography and site-inspections, mapping areas of surface cover in the watershed, analyzing drainage patterns, interviewing key park personnel, and reviewing previous reports and documentation provided by the City of San José. Questa obtained a quantitative measure of current water quality conditions with in-situ depth-integrated water quality testing and laboratory analysis.