If the Board of Clark County Commissioners adopts a new set of stormwater management rules as required by the Washington Department of Ecology, negative effects will be felt throughout the development community, say several people in it.
Some expect the county’s economic development efforts to be hampered, and it is unclear what the environmental benefits will be, said Steve Madsen, government affairs director for the Building Industry Assoc. of Clark County.
Early this year, the DOE issued Clark County a new National Pollution Discharge Elimination System permit that required the county to update its stormwater management rules to meet the guidelines in the DOE’s new Stormwater Management Manual for Western Washington.
The county’s current regulations are in line with the Stormwater Management Manual for the Puget Sound Basin.
The county is now revising the existing stormwater management programs, practices and ordinances, which are designed to prevent or reduce pollution in stormwater runoff and control runoff flows and volumes from construction sites, roads, homes, landscaped areas and parking lots.
There are several key regulations in the Western Washington manual that could have major effects on development and redevelopment efforts.
Currently, stormwater retention ponds are sized by matching peak flows from predeveloped and developed ground cover using a single-event model.
The new regulations will use a continuous simulation model that compiles rainfall data collected in the last 50 years. This will decrease the amount of runoff allowed to discharge from a site and require stormwater retention ponds to be double their current size in some cases.
And in cases where 5,000 square feet of new impervious surface is created or 10,000 square feet of existing impervious surface is disturbed, a new DOE standard requires engineers to model a site’s predeveloped condition as forested .
This significantly reduces the allowable stormwater discharges from a site and increases required pond sizes by four to six times. In some cases, the pond could be close to the size of a site, but typically it would be one-third to one-half the size of a site, said engineer Eric E. Golemo of Vancouver-based Sturtevant, Golemo and Assoc.
Golemo represents the county’s Development Engineering Advisory Board on the stakeholder advisory committee, which was established to help revise the code, but was speaking on his own behalf.
“The general opinion in the engineering community is that this is not a reasonable or practical requirement and is not justified in many situations,” Golemo said.
The goal is to match runoff peaks of a site in its predeveloped condition to stop the degradation of streams by controlling erosion impacts downstream to prevent further impacts to fish habitats and bolster salmon runs.
“In my opinion, it’s a very shotgun approach and the questionable benefit is disproportionate to the economic impact,” Golemo said.
Madsen said a 16-lot residential development losing four lots to stormwater retention ponds is unfeasible.
The economic impacts could be huge.
Developers will see a loss in the amount of land on which they can construct revenue-producing buildings and there will be less room for infill development, which may lead to more sprawl and less density, Madsen said.
Conversion of more than three-quarters of an acre of native vegetation to lawn or landscaping and 2.5 acres to pasture will be a triggering event for stormwater ordinance applicability, and there will be fewer exemptions. Particularly, rural and agricultural uses will no longer be exempt and will have to meet stormwater requirements, Golemo said.
And there will be little incentive to redevelop, which will be more difficult than before, he said.
Then there’s the potential impact on the county’s recently adopted comprehensive plan, which didn’t account for any loss of area.
“If we apply these standards, the plan won’t be adequate,” Golemo said.
It’s going to be more difficult to balance meeting client needs for a cost-effective project and having a stormwater management system that is approvable, said Neil Alongi, principal engineer with Vancouver-based consulting firm Maul Foster and Alongi.
However, the new rules push low-impact development techniques and there has been talk of moving toward infiltration with pervious concrete, infiltration swales and infiltration ponds.
Plus, water quality control is better because there are more choices and guidance’s on best management practices, Golemo said.
There are a few ideas floating around for possible solutions in cases where going back to forested, predevelopment conditions is not feasible. In those situations, Golemo and Madsen are pushing for a payment-in-lieu system.
A developer could instead match current flows offsite and pay into a mitigation fund that can be used to fund basin studies and regional facilities. Funds also could go toward stream restoration and to organizations such as Woodland-based Fish First, which works to restore native salmon and steelhead runs to levels sufficient enough to support responsible harvest by commercial, tribal and noncommercial fishermen.
“How many fish are the new regulations going to bring back?” Madsen said. “It’s much more difficult to go in and do basin planning, basin studies and coordinated efforts to identify the condition of the streams and how to improve them.
“It’s viewed through the DOE’s eyes that it’s just easier to regulate development.”
The county must submit its updated stormwater-related ordinances to the DOE by mid-February, and an overall stormwater management program by March 31.
The county is expected to adopt a final stormwater management program by August.
For the county commission not to adopt an ordinance that is compliant with the Western Washington manual would make the county incompliant with its NPDES permit and open up the possibility of third-party lawsuits, said Robin Krause, public works project manager for the county.
The county is aware of the private sectors’ concerns.
“We certainly understand – it impacts our projects, too,” Krause said. “We’re trying to find anything that’s available locally to try to make a reasonable ordinance that not only achieves the goals but is more applicable to our local area.”
Krause said the county is trying to better calibrate the model for Southwest Washington to more accurately represent local rainfall and soils. The county also is putting together a low impact development handbook.
“We’re looking at ideas like incentives or other things we have control over locally, but we have to be deemed compliant with that manual,” Krause said.
