City of Paso Robles


City of Paso Robles, CA

David LaCaro, Stormwater Program Manager

Located on the Salinas River north of San Luis Obispo, Paso Robles is known for its vineyards, almond orchards and olive groves.


Strict NPDES MS4 compliance requirements without the means to meet them.
Required to develop a method to assess stormwater pollutant load reduction in their local waterways, David was looking for guidance about the best way to approach these requirements. He needed a solution that would allow him to gather the information and compile it in user friendly and reportable formats understandable to his community and the regulatory agency. At the time, Paso Robles had no methodology in place to assess stormwater pollutant load reductions to their local waterways. Any analysis they did relied heavily on costly traditional water quality sampling that wasn’t not designed in a manner to generate data that would inform program decisions.


Accessible Insights Mean Effective Action

Connected through the Central Coast Low Impact Development Initiative, David and 2NDNATURE were key partners on a project advisory team to plot a course towards compliance. The first order of business was to develop a practical and user-friendly approach for David and his program to track and report stormwater pollutant load reductions to receiving waters. Working collaboratively with the project advisory committee the stormwater Tool to Estimate Load Reductions, or swTELR, was created. This computational approach has been applied to each urban catchment within Paso Robles MS4 boundary, and the results all at David’s fingertips within his 2Nform account. Having this standardized MS4 mapping and urban catchment information form the organizational foundation of David’s stormwater program within 2Nform has become key information to evaluate opportunities and communicate the impact of any future programmatic decisions.

Once the preliminary mapping and swTELR model results were in place, the City was able to inventory its stormwater assets in a couple weeks and use the automated results to develop maintenance schedules based on need rather than habitual timelines. The City was better informed about whether the actions were effective in managing stormwater quality. The modelled results now document the volume and pollutant reductions achieved throughout the City to date. The results are also mapped to highlight the City’s opportunities for targeted activities that could improve stormwater quality over time and optimize the use of limited resources.

Web-based, intuitive and easy to access from anywhere, the 2Nform platform has allowed David and his team to accurately assess current effectiveness of program activities while also providing insight into places where City could focus efforts to improve activities and increase pollutant load reductions to local waterways. The mapped outputs from the swTELR model has become a key cost-effective tool that empowers David to efficiently communicate where the city should focus long-term planning and achieve the goals of their stormwater program. The City of Paso Robles now has a standardized holistic stormwater accounting system that will serve as the foundation for funding future improvements throughout the City to reduce it’s impacts on local receiving waters and better manage its most valuable resource, water.

The Results

  • A user-friendly holistic system usable by non-technical staff
  • Compliant focused data that allows the city to more easily meet and communicate their compliance status.
  • Efficient collection, management, analysis and reporting of the wide-array of data and information critical to an effective stormwater program saving the City time and money.
  • A powerful communication tool for David to track the effectiveness of his stormwater program with individual decision makers, city councils, supervisors and the public year after year.