THE NEW WATERSHED: A Fresh Look at the Hidden Opportunities in Urban Runoff

version 1.0

by Owen E. Dell



1. ADEQUATE LANDSCAPED AREA: Review and if necessary modify existing requirements for adequate landscaped area on private properties to provide absorption of stormwater and groundwater recharge, as well as healthy root environment for trees and other landscape plantings.


1. ECOROOFS: Allow , encourage and subsidize water-absorbent living ecoroofs for new construction and remodeling. (Germany, Belgium, elsewhere. Tax credits in NYC, Seattle, Chicago, Portland, elsewhere)



1. ELIMINATE REQUIREMENTS FOR IMPERMEABLE DRIVEWAYS: Some local municipalities require impermeable pavingof driveways. The additive effect of these driveways on urban runoffis significant. Change ordinances to prohibit impermeable driveways and require permeable ones. Permit and encourage safe loose paving materials such as decomposed granite, mulch, turfblock and other vegetated parking surfaces, as well as other permeable approaches to driveways, turnarounds and parking areas.

( (Florida Concrete & Products Association Inc., 3030 Dade Ave., Orlando, Fla. 32804, 800-342-0080, (Cool Communities, Rome, GA.

2. ROOT-FRIENDLY PAVING: Encourage paving systems (including a no-paving option where applicable) that respect and protect the root systems of adjacent vegetation. Excavation deeper than 2-3 inches destroys the feeder roots of trees and shrubs.

3. REDUCE OVERALL PAVED AREA: Limit the percentage of land that can be covered with impermeable materials. Allow buildings equipped with ecoroofs to count as open space. Review each remodeling project for excess existing paving and require removal of paving where appropriate.

4. NON-TOXIC SEAL COATING: Develop and mandate the use of pavement maintenance materials that do not leach toxic waste.


1. PERMEABLE PAVING: Mandate permeable paving in all parking lots (Pervious concrete, turf block, gravel, decomposed granite, etc.).( (Florida Concrete & Products Association Inc., 3030 Dade Ave., Orlando, Fla. 32804, 800-342-0080, (Cool Communities, Rome, GA.

2. INTERNAL DRAINAGE: Grade paved surfaces to drain to centralpercolation beds or planter islands that are also designed as bioswales.

3. SUBSURFACE STORMWATER STORAGE CHAMBERS: Use the area beneath paved parking lots to temporarily store storm runoff by developing subsurface filter beds and other water-holding structures.

(T.R.E.E.S. Project:

4. PONDING ZONES: Direct runoff from paved areas to on-site ponding or recharge areas.

5. PARKING STALL SIZE REDUCTION: Reduce overall parking lot size by downsizing individual stalls.

6. ENCOURAGE ALTERNATIVE TRANSPORTATION: In all efforts to promote alternative forms of transportation, include information on the effect of motor vehicles and their support systems on the watershed.

7. NON-TOXIC SEAL COATING: Develop and mandate the use of pavement maintenance materials that do not leach toxic waste.


1. DRAINAGE SYSTEM MODIFICATIONS: Educate property owners about methods of modifying drainage inlets to provide ponding areas for slowing the discharge of stormwater into drainage systems. Where appropriate, require that ponding zones be a part of all newly constructed drainage systems. Educate the public about the wastefulness of conventional piped drainage systems and the benefits of the alternatives.

2. RETENTION GRADING: Where geologically and hydrologically appropriate, include bermed ponding areas and swales to hold water on site.


1. PROGRESSIVE GRADING ORDINANCES: Where appropriate, permit, encourage and require grading practices that permit rainwater to remain on site rather than running off. This would include the use of berming, ponding, dry streambeds, percolation zones, driveway drywells, percolation chimneys, elevated drain inlets, bioswales, filter beds, constructed wetlands, pervious paving, gravel or decomposed granite driveways and walks, ripraps and other methods and structures.

2. GRAYWATER SYSTEMS: Encourage the installation of graywatersystems on private commercial and residential properties. Develop educational programs on the implementation of graywater harvesting. Subsidize graywater systems where possible.(

3. CISTERNS & RAINWATER CATCHMENT SYSTEMS: Encourage and subsidize the installation of cisterns, water walls, rain barrels and other water catchment and storage devices.

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4. DRY STREAMBEDS: Install natural dry streambeds in runoff areas. Where appropriate, include percolation chambers to direct storm water into the ground.


1. BIOSWALES: Encourage the development of vegetated bioswales on private property. Require bioswales on new projects where it is geologically safe to do so. Educate property owners about the advantages of vegetated runoff zones and the techniques for creating them. Subsidize the development of bioswales as a less-expensive alternative to engineering approaches to stormwater management.


1. PUBLIC EDUCATION: In all public water awareness and irrigation management programs, include information on the effects of careless water management on the watershed.

2. ET-BASED WATER MANAGEMENT SYSTEMS: As technological advances permit, investigate the possibility of automatic ET-based irrigation controllers. Subsidize installation where possible.


1. FERTILIZER APPLICATION MANAGEMENT: Develop and follow stringent guidelines for fertilizer application on all private properties.

2. TRAINING PROGRAMS: Train private grounds maintenance employees and home gardeners in proper fertilizer use.

3. MUNICIPAL COMPOSTING AND DISTRIBUTION SYSTEM: Develop and implement a municipal greenwaste composting system. Educate the public about the advantages of using compost instead of fertilizer.

4. USE OF ORGANIC FERTILIZERS: Encourage the use of organic fertilizers over chemical fertilizers. Organics are more resistant to leaching and are also better for plants, and the soil foodweb.

5. LEAF LITTER RETENTION: Encourage the practice of allowing leaf litter to remain in place where appropriate. Removal of leaf litter disrupts the nutrient loop and makes it necessary to import lost nutrients in the form of fertilizers. It also exposes the soil to drying and erosion, leading to excess silt flows.

6. LOW NUTRIENT-REQUIRING PLANT SPECIES: Encourage the use of plants that require little or no supplemental fertilization.


1. PESTICIDE USE EDUCATION: Public education program to reduce agricultural, residential and commercial pesticide and herbicide use and misuse.

2. PESTICIDE BAN FOR ORNAMENTALS: Follow the lead of Halifax, Nova Scotia in banning the use of pesticides for ornamental plants.


3. PEST-SUSCEPTIBLE PLANT REDUCTION: Remove species that are known to be especially susceptible to pest and disease infestations and replace them with durable, low-maintenance species.


1. MULCHING PROGRAM: Encourage the use of organic mulches in private landscaping. Mulch improves water absorption, reduces runoff, improves the soil foodweb, prevents surface erosion, reduces water loss by evaporation, improves the root environment for plants and improves the appearance of planting beds.

2. PUBLIC EDUCATION: Educate the public about the advantages of mulch.


1. REGULATION: Develop and enforce strong, effective regulations for management of construction sites to prevent erosion, loss of topsoil and siltation. The regulations of many states are apparently much more stringent than California’s.

2. BUILDING TRADES EDUCATION: Develop and implement educational programs for building and other contractors, subcontractors in all trades and others in related fields. Provide programs for management and laborers, in Spanish and English.


1. RUNOFF MANAGEMENT PROGRAM FOR STABLES, KENNELS, ETC.: Develop strategies for keeping and treating animal effluent on site at public and private animal holding and training facilities. Regularly inspect these sites for compliance. Develop a system of sanctions for violators.

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