Landscaping features that serve a single purpose are rather outré these days. Instead, the trend among forward-looking landscape architects, developers, and homeowners throughout the East Bay is to design for many purposes. Aesthetics remain a central concern, but so are water retention, attractiveness to pollinators, and other ecological functions. That's why curbside bioswales and other forms of bioretention are such a great idea: Not only do they beautify sidewalks, curbs, and gutters with landscape-quality plantings and play a part in a city's broader ecosystems, but they also filter pollutants from stormwater and runoff before it has a chance to make it to the bay. Within the last couple years, the City of Emeryville has installed attractive, self-watering bioswale landscapes at gutter locations throughout the city, capturing runoff before it flows down the drain, sprucing up neighborhoods with native plants, and cleansing street-level pollutants at the same time: talk about a triple bottom line.