Future of Rainwater Harverting

Generally most people will not implement sustainable solutions unless there is a financial incentive, e.g. rebate, grant; not loan, or there is a government regulation or resource rate to require these solutions under specific conditions, e.g. new, re, major construction. For example, in Santa Monica, in the 1980s we required low flush toilets, showerheads and aerators to save water. It was a new strategy and it forced the market to produce more efficient toilets and other water devices from the 7 gallon guzzlers. We also provided a financial incentive option. And it worked; the market adapted to supply more efficient toilets, and promoted competition. In Santa Monica and other cities, sprinklers are required in a building for safety purposes when your construction project exceeds a threshold. Some areas require solar systems and weather-proofing to reduce energy use and produce renewable energy. While additional costs are imposed, in the long-term, generally, one’s costs will be reduced, health and safety improved, and during emergencies one could be more self-reliant from the municipal grid.

Firstly, I believe that codes should be upgraded to include building requirements for harvesting precipitation for direct and passive applications on parcels and the public right of way. In Santa Monica, we have had such a requirement since the mid-1990s, requiring post-construction BMPs to reduce rainfall from leaving a parcel. However, this requirement has been focused on passive solutions, redirecting this water from the storm drain system to onsite infiltration. But this strategy is often inefficient if one’s soils are C and D, clayey, or there is little open space to infiltrate and at the same time avoid damage to a building foundation. Moreover, infiltrating additional rainfall from impermeable surfaces to permeable when it is raining can saturate soils. And generally, this parcel by parcel strategy does not help alleviate excessive groundwater mining because of the small amounts of recharge volume and uncertainty if such infiltration can reach a viable aquifer. A more sustainable strategy is to store rainfall for indoor uses and future landscape irrigation when it is not raining, which directly reduces the use of potable water.Codes should be put in place to require, during construction of specific levels, rainfall harvesting systems for pre-treatment, storage, polishing and end uses, such as irrigation and indoor flushing, the two most common uses for parcels.

A second strategy I believe could be effective is the implementation of rainfall or impermeable surface fees. In Santa Monica and in many other cities, these parcel fees are based on land use type and runoff coefficient, and size of property. In our city, we use these fees for building new public green infrastructure, O&M of existing BMPs, and a small portion for financial incentives for rainfall harvesting systems (rain barrels and cisterns) and downspout redirects. These revenues can be used to establish financial incentive programs to fund retrofitting of existing buildings with green infrastructure described above. Property owners who want to install a rainfall harvesting system for direct end uses can be paid in part by these fees. And for those property owners who have such systems, their annual rainfall fee would be removed or significantly reduced. What complicates this strategy is that, generally, such fees cannot be passed by municipalities’ governing bodies. The approval has to go the voters, and we know how difficult it is to pass a new fee or tax, even one that supports environmental protection. Rainwater/stormwater is not classified the same as natural gas, electricity, drinking water, and sewage. Ideally, rain/stormwater need to be re-classified like these other utilities so that governing bodies can impose rates without having to go to voters.

This vision is a two-prong comprehensive strategy to address all land use and ownership: first, one program addresses private and public parcels, and public right of ways that have new or major construction; second, one program addresses existing parcels not undergoing construction, in which a building is retrofitted with an appropriate rainfall harvesting systems for a specific site. This vision puts a community on a path to eventually have all land with a sustainable water harvesting system, to reducing runoff and the problems associated with too much water in the storm drain system, and to maximizing local water harvesting and water self-reliance, and sustainability.

Future of RWH – ARCSA Conference, Panel Discussion November 6, 2013   
Neal Shapiro*, Secretary ARCSA(Office of Sustainability & the Environment, City of Santa Monica* Expressed views are personal and do not necessarily reflect the City’s)