The prekindergarten expansion that Mayor Kenney hopes to achieve with funds from his soft-drink tax has gotten more attention, but it is his initiative to repair dilapidated parks, libraries, and recreation centers that will have the more immediate impact on Philadelphians' quality of life.

That multiyear, $600 million project, which Kenney hopes to begin next spring, got a big boost with Monday's announcement that the William Penn Foundation will kick in up to $100 million. The city plans to borrow $300 million and spend $48 million in capital improvement funds, with other support coming from state, federal, and other private sources.

The Penn grant is a vote of confidence that the mayor also needs from City Council, which will have its say as to what gets done when. Councilwoman Maria Quiñones-Sánchez recently pointed out that while an initial priority list put Cruz Recreation Center in gentrifying Northern Liberties at the top, she thinks Nelson Playground in struggling West Kensington needs help sooner.

Janet Haas, who chairs the Penn Foundation board, said making the investment in the program dubbed Rebuild Philadelphia was not an easy decision. She said she was originally skeptical and board members asked countless questions. In the end they decided the potential outcome was worth the risk. The philanthropy will help the city find more funding.

Rebuild wants to also become a job-creation program in neighborhoods where unemployment is extremely high. On its website Rebuild says it wants to "create economic opportunities" for minority and women-owned businesses. That is a worthy goal, but care must be taken to avoid the pitfalls of previous city construction initiatives marred by favoritism and subcontractor scams.

This project is much too important for the city to let pay-to-play deals or the political strength of building-trade unions get in the way of making sound decisions about who can actually do the required work. Some parks and rec centers haven't seen repairs in decades. Eight library branches never opened last summer because they lacked air-conditioning.

That's unacceptable when you consider the role these facilities play in many neighborhoods. Rebuild says crimes by young people triple after school when working parents aren't home. That changes when you give children access to libraries and rec centers to engage in positive activities. Adults are healthier when nearby parks offer safe opportunities for walking, jogging, or other exercise.

Kenney has promised hearings so the public can have input into what work is done. There will be disagreements, but officials should not avoid difficult decisions about facilities that, due to disrepair and population shifts, may no longer be useful. The resources won't be infinite. Spend them where they will do the most good.