In urban settings, stormwater infiltration is a big deal. Intact, or at least diverse, ecosystems should contain range of plants with a range of root systems: some shallow, some deep, some branched, some taproot. This range provides multiple channels for rainwater to soak into the ground, or ‘infiltrate.’ For cities that pipe stormwater into treatment plants, improved infiltration means cost savings on several levels: less water to treat, less dirt washed in, less wear on pipes.