With help from the City of Portland, St. Philip Neri Parish is following a biblical mandate to care for planet Earth.

Supported by a $5,000 grant and plenty of volunteer labor, the Southeast Portland faith community will build a small wetland on church property. The vegetated trench will absorb parking lot and building runoff, preventing the tainted water from reaching local creeks and rivers.

The 5,000-square-foot sponge-like ecosystem, planned for completion by November, is part of a parish commitment to follow recent church teaching on the environment. In 2001, the Catholic bishops of the Pacific Northwest issued a pastoral letter on the Columbia River, asking communities to care for the 1,200-mile waterway. The bishops cited ancient Scripture in which humans are called to be caretakers of the earth.

'This project flows from the bishops' letter, which says, 'Let's be good stewards,'' says Patrick Murphy, a member of the Southeast Portland parish and a civil engineer who is managing the plan.

The city's 1930s-era storm-water and sewage pipes create a problem in substantial rain. Because the systems are combined in many places, heavy precipitation on a city increasingly covered with asphalt and buildings can cause an overflow. That sends untreated runoff and even raw sewage into the Willamette and Columbia Rivers.

The city is upgrading the pipes and the sewage plant. Home and business owners have been urged to disconnect building downspouts from under-street storm pipes, re-routing runoff onto lawns. The absorbing and filtering bioswales, which create small natural areas, are another innovation.

'We are aiming to prevent parking lot pollutants from going into the Willamette River during overflow,' says Murphy.

With 33,000 square feet of parking lot space, St. Philip Neri is a significant source of runoff. The lot sheds more than 800,000 gallons of water per year.

Pollutants in storm water include soot and hydrocarbons, copper from brake pads, zinc, dissolved metals, motor oil and other petroleum products, phosphorus, nitrogen, antifreeze, rubber from tires, cadmium and animal waste.

Roots and bacteria can break down some pollutants, and plants actually use other compounds as fertilizer.

The bioswale, a serpentine ditch on the southwest corner of the parish grounds, will be full of native plants that will take up the water and create habitat for birds and other wildlife. A decorative fence will surround the created wetland.

In addition to Murphy, the design team of parishioners includes architect David Webb, plant specialist Mary Jo Mann and city environmental workers Doug Hutchinson and Eugene Lampi.

Future plans call for pipes or planters that will carry water from the roofs of parish buildings to the bioswale.

'Retrofitting existing development is going to be tricky, so stewardship projects like St. Philip Neri, where individuals and organizations take responsibility for the rain that falls on their property and divert it in creative, innovated ways, are very encouraging,' says Amber Marra of the city's Community Watershed Stewardship Program.

St. Philip Neri is the second Portland-area church to get a bioswale grant. St. Andrew Presbyterian in Southwest Portland recently received funds to remove invasive non-native plants, restoring a tributary of Fanno Creek and installing a parking lot bioswale.

'I do think more groups, and ones not traditionally environmentally oriented, are getting involved with watershed stewardship,' says Marra. 'People are more aware of their surroundings and the differences that individuals can make on the small and large scale.'

This year, St. Philip Neri was one of 30 applicants for the $45,000 pool of funds.