[Originally published in The Wendel Report, The Environmental & Real Estate Update, Winter 2010]

Under several new rules and policies, landowners, developers, architects, and project designers will have to pay much closer attention to rainfall in planning development and redevelopment projects. 

Historically, storm water was something hastened from property by various components of a storm drain system, the primary objective of which was rapid drainage to avoid flooding. That approach created water quality problems. Now, a number of forces are coming together to require far more elaborate facilities to filter, store, evaporate, infiltrate, and detain runoff on site, placing storm water issues front and center in project design. These measures are commonly described now as “green infrastructure,” and “Low Impact Development” or “LID.”

The paradigm began to shift in the early 1990s when storm water regulations required development projects to include “post-construction controls” to reduce pollutants in storm water discharges after construction projects were completed. Rainwater not only picks up countless pollutants as it drains over and through our cities on the way to streams, lakes and oceans, but impervious surfaces dramatically increase the volume and flow rate of storm runoff from storm events, causing down-stream channel erosion and sediment discharges to receiving waters.  These hydrological impacts of development can be reduced with LID features such as pervious paving, rain gardens, grassy swales, and detention basins. 
LID is spreading through and beyond urban areas, and is evolving from innovative approach to established practice to mandatory standard. With LID comes regulatory debates and permitting issues over objectives such as whether runoff from new development and redevelopment projects must match pre-project or pre-development hydrology. There is also tension, particularly with space-limited infill projects, between parcel-by-parcel regulatory demands and greater cost effectiveness of regional facilities.

LID requirements may well expand into smaller communities. EPA is overhauling storm water regulations with a new focus on new development, the majority of which occurs in suburban and rural communities not currently subject to post-construction control requirements.  EPA is also considering retrofitting requirements, which may substantially affect redevelopment projects. The target for draft rules is September, 2011, and final regulations by 2012.

Meanwhile, several other laws are underway that also draw design attention to site water management. First is the new California Green Building Code (“GBC”), or “CalGreen Code,” that will take effect January 1, 2011.  While clearly competitive with LEED standards, GBC applies to all structures, where LEED is electively applied to perhaps 2% of new construction. The new GBC mandatory measures require LID-type features to manage runoff as part of planning and design.  They also contain water use efficiency requirements, including separate metering for indoor and outdoor water use, irrigation system specifications and an outdoor water budget. The GBC dovetails with new water-efficient landscape requirements appearing in local ordinances, as required by AB 1881.

Climate change and water supply issues will also play a role in project design.  No longer to be dismissed as a waste as in years past, storm water will play an increasingly important role in future water supplies. We may not be drinking from our downspouts anytime soon, but projects designed to capture and store storm water for landscape irrigation will ease the demand for potable water, reduce discharge of pollutants into waterways, and help to recharge groundwater basins.  Project proponents can expect to see such measures required by municipalities attempting to meet new water conservation requirements, including SBX7-7 (Steinberg), requiring a 20% reduction in urban per capita water usage by 2020. 

Reuse of storm runoff, along with wastewater recycling, are among the AB 32 measures targeted to reduce greenhouse gas emissions from significant energy usage associated with water transport and treatment.  The State Water Board has already adopted a statewide permit regulating the use of recycled water for irrigation, and the Department of Public Health will establish uniform criteria for recycled water, as required by SB 918 (Pavley). This past legislative session saw a strong effort to push storm water reuse with the introduction of several, and passage of at least two, significant bills. The Rainwater Capture Act of 2010, AB 1834 (Solorio), removing certain obstacles to installation of rain water collection systems, and SB 1173 (Wolk), prohibiting use of surface or groundwater for non-potable uses when recycled water is available, were both vetoed by the Governor. Nevertheless, developers will face increasing pressure to design and plumb their projects to utilize captured storm water and, as it becomes available, recycled wastewater in order to reduce use of potable water for irrigation. In the next year, urban water suppliers will complete their first Water Supply Assessments, which may identify aggressive demand management measures in order to ensure water is available for new development. 

Finally, but by no means the end of the story, SB 375 (Steinberg) seeks to reduce vehicle emissions by shifting development patterns, encouraging greater density along public transit corridors. This is bound to create tension between higher density and open space needs for LID. To complete successful projects, developers, and their architects, engineers, contractors, and lawyers, will need to be alert to the multitude of new and changing policies, practices and requirements that drive water use and storm water management design decisions on their project sites.