Jay Manning, director of the Washington Department of Ecology,
was in Bremerton today to get the lowdown about low-impact
stormwater management from folks at the Home Builders Association of
Kitsap County.
Art Castle of the association is leading a local group of
officials in the development of a “cook book” of low-impact
practices designed to dovetail with state rules for managing
stormwater.
Art Castle, left, pours water
on pervious asphalt while Jay Manning watches. The water does not
run off or pool up; it just runs through.
Kitsap Sun photo
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The parking lot at the office of the Home Builders Association
happens to be built with pervious asphalt and various kind of
pervious pavers. Manning watched as Castle poured water from a hose
onto the pervious asphalt. No runoff or pooling was evident, as the
water penetrated straight into the pavement.
Castle was glad to have some time to talk with Manning, a native
of South Kitsap, because the Home Builders group has run into some
regulatory obstacles with respect to the upcoming “cookbook.”
For example, engineers are debating how fast water can pass
through pavement within a given design and whether that rate of
penetration will hold up over time. Pervious pavement depends on
creating “pores” during construction and keeping those pores open
as time goes on. Sometimes the owner must use a pressure washer to
reopen the pores.
In this example, the debate is about finding an acceptable rate
of water penetration for a given design. If the assumed rate is too
low, a developer will be required to build a backup stormwater
system, such as a pond. That raises the cost of development and
discourages the use of low-impact methods.
If the assumed rate of penetration is higher than what actually
occurs in a heavy storm, then the water runs off the pavement with
no place to go. That leads to flooding of streets and other
problems.
Those are the kinds of issues that Castle wanted to address with
Manning.
Manning told me that this meeting comes at an opportune time,
because his agency must decide how to respond to a recent ruling by
the Pollution Control Hearings Board that mandates the use of
low-impact development wherever “feasible.”
See Kitsap Sun story of Aug. 8.
Manning asked Castle to describe when low-impact development
would not be feasible. Castle said he knows of three conditions
that would preclude the use of LID: on sites with steep, unstable
slopes; in places where you find especially dense clays that cannot
pass water; and in areas with high groundwater levels that prevent
water from soaking in.
Manning said he faces a decision about whether to appeal the
hearing board’s decision to court or else live with it.
“If we live with this decision,” he said to me, “then what’s
that going to mean for the Phase 1 permit (larger cities and
counties) and the Phase 2 permit (smaller cities and
counties)?”
Basically, state requirements would have to be rewritten.
The specific ruling (PDF 212 kb) by the Pollution Control
Hearings Board was for Phase 1 jurisdictions, but it signals the
board’s position for the Phase 2 hearing, scheduled for October,
Manning said. If Ecology does not appeal the ruling to the courts,
agency lawyers could try to settle some key issues before the
October hearing, he said.
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