Having Philadelphia hailed by influential environmental groups for its plan to deal with storm runoff that contributes to water pollution is a win-win for the city.

If the plan given official approval on Wednesday works as designed, Philadelphia in coming years will be greener - with more parkland, gardens, trees, and cutting-edge streets and paving that soak up water, instead of letting it run down the drain.

With it being so important for a city's image and growth to create positive buzz, it's also an achievement that other metropolitan areas are said to be watching Philadelphia.

According to a New York-based environmental group, the city is being seen as "a national model for how to clean up polluted urban waterways."

The Water Department-led effort to minimize rain runoff that triggers polluting sewage overflows will rely on infrastructure improvements that permit water to percolate into the ground rather than storm drains.

That's a far greener and less intrusive approach than the most likely alternative - which would be tunneling deep underground to create caverns where storm water is held and then pumped out to be treated, as is being done by the District of Columbia.

So, rather than a major, costly public-works project to build storm-water holding tanks, the city's strategy is to let a thousand smaller infrastructure projects bloom - both public and private.

Some streets due for reconstruction will be repaved by the city with porous materials, as was already done on the 800 block of Percy Street in Bella Vista as a pilot effort. Street trees, similarly, could be fitted with catch basins to collect water, and paved areas around city facilities will be converted into green spaces.

Over a 25-year span, the city will devote $2 billion to these upgrades. Much of the heavy lifting on this plan, though, must be done by private property owners. That's a potential strength, but could become a pitfall, if not enough property owners opt in.

No doubt, some building owners will understand the value and move ahead with projects such as creating green roofs that soak up water. But there are hundreds of other business properties with vast parking and other impervious surfaces whose conversion would be costly, yet help make a big dent in water pollution.

A looming hike in storm-water management fees on properties blamed for runoff has put those owners on notice that they could save on fees by going green. At the same time, the city will need to come up with positive incentives for owners to make conversions in this effort to tame the rain.