MOST OF US, UNTIL the bills come due for repairs or expansion, take for granted "infrastructure" -- the highways, sewers, storm drains and utility lines that underpin our society.
Even more so do we take for granted what natural resources planners are beginning to view as our "green infrastructure" -- our forests, wetlands and other natural spaces.
Quietly, and largely for free, the green infrastructure goes about cleansing our air and water, producing wildlife, providing recreation, supporting a forest industry and simply making life more aesthetic.
Green infrastructure does not lend itself to traditional notions of "improvement" like opening a road or cranking up a new and cleaner sewage treatment plant.
For example, people often ask how much Maryland's Critical Area law of 1984, restricting development of the Chesapeake Bay's remaining natural shoreline, has "cleaned up the water."
The answer, of course, is not a bit -- preserving a green buffer along the water's edge "merely" keeps the bay from getting more polluted with runoff from the land; it also prevents the visual degradation of waterfront development.
Except for the occasional park dedication, politicians don't officiate over ceremonies celebrating bad things that didn't happen.
At first glance, renaming trees and marshes "green infrastructure" seems more faddish than substantive; but there is good reason that Maryland's Department of Natural Resources has been working the last four years to develop the concept.
Just as government must plan traditional concrete infrastructure to make efficient use of limited money, so does the DNR, the state's major land conservation agency, need a unifying strategy to effectively guide its open space investments.
The agency is responsible for, or involved in, a burgeoning number of programs aimed at protecting natural areas, from traditional state parks and forests to Program Open Space and the new Rural Legacy bond issue, all of which involve millions of dollars a year for land acquisition.
The green infrastructure initiative the DNR is preparing brings a new level of sophistication to protecting the state's remaining natural areas.
An effort to put all state and federal environmental data in the same software format was the first, crucial step.
What that means is that the DNR can break the state down into 134 watersheds, or drainage basins, and summon an impressive array of vital information for each.
For a given watershed, this information ranges from the erodibility of soils to the number of households on septic tanks, to the miles of intact stream-side forest, to zoning, farms preserved from development, and a host of water quality measures -- even trends in a given river's seafood industry.
These watersheds are on the order of a reservoir, like Loch Raven or Prettyboy, or a small river, like the Magothy. Increasingly, the agency's analyses can go to much smaller units, breaking the state into 1,100 watersheds.
This is all in prelude to the real work of identifying a series of "hubs and links" that form the backbone of Maryland's green infrastructure, John R. Griffin, secretary of natural resources, said in an interview last week.
The "hubs" are unbroken blocks of forest and other natural open space of at least 2,000 acres (about three square miles); also "local hubs" of at least 500 acres.
Such chunks of open space have far higher values for many kinds of wildlife than lands fragmented by development.
The "links," usually following stream or river corridors, are green spaces connecting the hubs, allowing wildlife -- also humans seeking recreation -- to move freely among the hubs in an increasingly developed landscape.
Where the rubber really hits the road is that the DNR, using computer graphics, can overlay this green infrastructure with its environmental data sets to rank each hub and link in terms of ecological value, vulnerability to development and potential for preservation or restoration.
This way, Griffin says, the agency can allocate money more efficiently; it can also get away from letting politics determine where it acquires lands.
Other benefits readily come to mind. Just as transportation plans signal developers and local government where to grow, green infrastructure priorities might steer development plans away from some areas.
In addition, other land preservation groups, from the Nature Conservancy to local land trusts, could tie their priorities to the green infrastructure.
Local governments, where much of Maryland's land use power resides, could incorporate it in their plans. Selling the concept locally throughout the state, however, "will be a challenge," Griffin says.
"It's a fundamental shift in thinking to get governments to regard green infrastructure as they do other infrastructure investment," he says.
There is no time to waste. Governor Glendening's "Smart Growth" and other policies to focus development away from rural areas notwithstanding, Maryland is in a grim race to protect all the natural lands it can.
Protected lands and developed lands each cover about a million of the state's 6.3 million acres.
Such is the pace of large-lot, sprawl development that Maryland is projected to consume as much open space in the next 25 years as it did in its last 300 years of development.
And beyond that, the sky's the limit. We have enough open space zoned, statewide, for residential housing to accommodate five times the projected development of the next 25 years.
That constitutes a huge potential for the kind of sprawl that will further fragment some of the "hubs and links" the DNR is identifying.
You can always build another road or lay another sewer line; but it is virtually impossible to resurrect green spaces and corridors where housing developments have sprouted.
Pub Date: 12/04/98