Pilot installations, full-scale developments, and academic research have shown LID to be a technologically feasible and effective stormwater management approach. Current impediments to broader application of LID are often institutional barriers – zoning or regulatory policies that discourage or limit its use. Despite these obstacles, municipalities need to press on and should review applicable codes and regulations for opportunities to encourage the use of LID (some examples are provided below). Municipalities should streamline the permit process. Waivers for the small land disturbances typical of LID are a regulatory option available in many jurisdictions and go a long way in streamlining the permitting process. Applicable guidelines should also be reviewed to confirm that they allow for on-lot stormwater management and do not prohibit such practices. 

Stormwater collection and infiltration areas in an apartment complex.
Source: LID Center
(click on thumbnail for enlarged view)

Some of the largest impediments to the implementation of LID are the often unintentional zoning and code barriers, such as those explicitly requiring curb and gutter or prohibiting open channel conveyances. These zoning ordinances and codes require obtaining a waiver to implement LID practices, greatly lengthening the development and construction process. Additionally, local plumbing codes, like those requiring downspouts to be directly connected to collection systems unintentionally prevent downspout disconnection efforts and the use of on-site stormwater management.  

A number of municipalities have developed economic incentive programs for developers, homeowners, or commercial property owners that use LID. As stormwater utilities are being created in municipalities to fund stormwater control programs, some jurisdictions are incorporating provisions designed to encourage alternate stormwater controls. Portland, Oregon and Orlando, Florida provide a reduction in the stormwater utility rate for commercial properties with on-site stormwater management. Several municipalities subsidize downspout disconnection programs, either providing a cash incentive to homeowners and community groups or having municipal personnel provide the service for free. 

Runoff from a disconnected downspout drains to a vegetated infiltration area.
Source: LID Center
(click on thumbnail for enlarged view)

Code and Regulation Review 

Issue 1:       Outdated and compartmentalized community zoning and subdivision requirements often make it difficult for municipal officials (elected, appointed, or volunteer) to consider and approve projects integrating LID practices into designs. In addition, limited municipal budgets and depleted planning staff resources may preclude performing revisions to local zoning codes.    

Strategy:     Build flexibility into zoning classifications and subdivision requirements by inserting language allowing the use of overlay districts, Planned Unit Developments (PUDs), or conservation development ordinances. These zoning classifications provide a builder with design and engineering flexibility. Often, adoption of a new zoning classification is far easier than a complete rewrite of local codes.

1.       Develop a model PUD for community adoption.

2.       Develop a model conservation development ordinance that promotes open space and LID.

Issue 2:       Some subdivision requirements unknowingly promote unhealthy stormwater management practices by mandating outdated development design standards and specifications. For instance, street widths of 36' or greater will lead to increased stormwater volumes and velocities, as compared to streets that are 32' wide or narrower. Further, narrower streets encourage better community design. 

Strategy:     Identify design requirements within subdivision codes that lead to the generation of stormwater or prohibit LID.

1.       Examine minimum lot size, street width, sidewalk width and use, house setbacks (front, side, rear), curb and gutter use, driveway material.

2.       Examine requirements for stormwater management (e.g., engineering design, piping, use of retention ponds). 

      Provide incentives for LID including the use of:

1.       Density bonuses;

2.       Reduction of municipal submittal fees; and

3.       Early construction start permits. 

Issue 3:       Often, perceptions that LID practices are ‘untested’ may undermine attempts by planning staffs to introduce them into current projects.   

Strategy:     Encourage the use of pilot projects or projects designated as innovative.

1.       Create subdivision approval language that encourages innovative and pilot projects.

2.       Create new engineering submittals for plan sets that include innovative LID controls as part of environmental protection plans that might also identify wetlands, tree protection areas, and other environmentally critical features. 

Issue 4:       Stormwater permit writers need to better coordinate with planning staffs to identify strategies for stormwater mitigation.    

Strategy:     Similar to a pre-construction conference, planners and writers should consult to identify best management practices applicable to an individual project.