May 1, 2014

Low Impact Development Rules Impacting Development Soon


In August 2012, the Washington Department of Ecology (“Ecology”) issued a new Phase I National Pollutant Discharge Elimination System (“NPDES”) permit that took effect in

August 2013.  This new permit stemmed from a 2007 prior ruling from Washington’s Pollution Control Hearings Board (“PCHB”), which requires the use of low impact development (“LID”) techniques for new private and public projects “where feasible.”

Low impact development techniques attempt to mimic the natural pre-developed environment by attempting to return much of the rainfall to the ground where it falls, rather than treating it in some other medium and then discharging to a pipe where it eventually joins a stream, lake, or area where it eventually infiltrates. The 2013 permit specifies preferences for LID techniques such as permeable pavement, bioretention, rain gardens, dispersion, and other methods.  An excellent example of a local commercial development utilizing LID techniques can be found at the Grand Central Retail Center, which uses rain gardens, permeable pavers, and rainwater harvesting barrels for future use.

Under condition S5.C.5.b of the new permit, Phase I jurisdictions like Clark County must “review, revise and make effective their local development related codes, rules, standards, or other enforceable documents to incorporate and require LID principles and LID best management practices.”  But jurisdictions required to implement the LID requirements and the development community remain wary of implementing such radical changes on a statewide basis without a better understanding of the long-term implications, particularly regarding maintenance costs.

All Phase I jurisdictions in Washington (King, Pierce, Snohomish, and Clark counties, along with the cities of Seattle and Tacoma) and the Building Industry Association of Clark County challenged the 2013 Phase I permit, citing issues such as the permit failing to account for serious concerns around some of the LID techniques, in particular permeable pavement and bioretention facilities.  Additionally, they argued that Ecology failed to consider economic considerations as to when LID should be mandated for individual development sites.

On March 21, 2014, the PCHB issued its decision in the case, essentially affirming most aspects of the permit.  They did, however, require some modifications to the permit, including the removal of the requirement of permeable pavement from “heavily traveled roads.”  The PCHB also confirmed the power of local governments to suggest alternative “infeasibility” criteria to Ecology for consideration.

Clark County is currently in the process of both developing its code and crafting a stormwater manual specific to the county in order to comply with the requirements of the new permit.  Draft updates are due to Ecology for review on June 30, 2014, and with implementation scheduled to start by June 2015.

Phase II jurisdictions – those with a population over 10,000, like the cities of Vancouver, Camas, Battle Ground, and Washougal – must implement LID into their codes by December 31, 2016, coinciding with the next Growth Management Act Comprehensive Plan update.

The use of LIDs will not only change the landscape of the built environment, but will also require businesses and developers to change pro-formas to consider the short and long term costs associated with LID.  This is made increasingly complex by the fact that some LID techniques may be located on individual lots, but function to serve the whole development.

For more information on this topic, please contact or call (888) 598-7070.


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