Public Comment

Commentary: Storm Drain Project Threatens Tidal Lagoons

By Mark Liolios
Thursday June 19, 2008 - 10:03:00 AM

In the past decade, Berkeley’s Aquatic Park has been undergoing a striking renewal. Dreamland for Kids and the Addison Street bicycle/pedestrian bridge bring new life to the park, as do the community organizations that have established programs in park buildings. Habitat restoration along the bay shoreline has created new shelter for wildlife. However, these biologically rich tidal lagoons are at risk of repeated toxic contamination if the Berkeley City Council approves plans for a $2 million storm drain construction project. 

On Tuesday’s council agenda is the Aquatic Park Improvement Program (APIP) proposal. The proposal details how clean water bonds could be spent. While a stated goal of APIP is to improve wildlife habitat, the bulk of the funds would be used to create new storm water outlets into the park from the storm drains at each end. 

The purpose of this portion of the project is to increase tidal flow through the lagoons, but the expanded storm drain openings at the Potter and Strawberry Creek culverts would also allow the city to direct floodwaters to the park’s wetlands. Such water storage is one strategy to reduce flooding upstream, but not the only one, and the progressive damage to water quality in the park cannot be denied. 

The harm urban runoff causes to the shallow ponds of the park has been well known for decades. As industrial discharges into the park were largely eliminated in the ’60s, it became apparent that the many toxics in storm water runoff—nonpoint source pollution—were a major cause of lagoon contamination. 

In 1970, the State Water Board met in the City Council Chambers and issued an order permanently prohibiting the City of Berkeley from discharging storm water into the park’s lagoons. The order included a mandate that the city construct a storm water diversion pipe to carry runoff from local drainages away from the park and out to the open bay where dilution would minimize its negative impacts. 

The city is not now in compliance with that order. As part of the project planning, the consultants discovered that the diversion pipe does not meet its stated design purpose during times of heavy rain and high tides. Rather than carry local pollutants away from the park, water in the pipe actually flows backwards, carrying toxic runoff from the city’s entire southern watershed and discharging it into the lagoons at multiple locations. The unsealed access covers on the pipe literally explode upwards during major storm events, dumping more storm water into the ponds. Contaminated water also pools in the freshwater wetlands where the remnants of Potter Creek reach the bay and the great egrets of the region gather nightly to sleep. 

Besides the diversion pipe functioning opposite its intended purpose, gates that formerly blocked storm water intrusion were removed a decade ago—without required notification to the Water Board—allowing additional storm flow directly into the lagoons. 

The APIP proposal project calls for creating larger connections between the city’s two major storm drains and the waters of the park. Compliance with the Water Board order demands that all storm water be blocked from entering the lagoons. Clean water and wildlife habitat goals also demand that all storm water be diverted away from the park. 

The proposed discharge valves, however, would be operated by the city’s storm water managers. Their mandate is to limit flooding in commercial and residential districts and the new gates would allow them to shift storm water to the park. Flood control east of the railroad tracks would be the primary operational purpose of the discharge gates, not the protection of birds and their habitat. 

One standard flood control option was not studied, however—the installation of high-pressure pumps to move water from east of the railroad tracks directly out to the open bay. Pumps are used in other cities around the bay, and are able to move high volumes of water, protecting both human and natural environments from flooding. 

Although it is tempting to look at Aquatic Park as a storm water surge basin, a single storm could kill the food base when the highest bird population is present and when plentiful food is most needed. 

Storm water is the primary source of water pollution in the park. The negative impacts of these discharges into the park are already well known, as they were studied in the 1994 Aquatic Park Water Quality Study that first proposed opening storm drains into the park and using the park for storm water treatment. 

Four biotoxins in the runoff are at levels exceeding Water Board water quality objectives. Coliform levels are 10,000 higher than board objectives. Shorelines near discharge pipes are layered in bands of plastic and other trash. 

Even if the storm water were filtered to drinking water standards, the sudden loss of salinity can be toxic to the park’s marine life, the food base for migratory birds. Offshore bird roosts disappear when floodwaters are diverted to the lagoons, depriving birds of protected resting spots. Erosion of the shoreline is exacerbated, speeding the loss of shoreline trees needed by egrets and herons for resting and sleeping. Erosion also accelerates the reduction in water depth, raising summertime water temperatures and driving oxygen from the water. 

The storm drain construction project has the support of no environmental group. Citizens for East Shore Parks (CESP), the Golden Gate Audubon Society, and the Sierra Club have all expressed opposition to using the park’s lagoons for storm water discharge. 

On top of all this, the city is seeking a construction permit from the State Water Board that overturns the permanent prohibition on storm water discharge into the park and replaces it with a new permit allowing such toxic discharges in perpetuity. 

The Sierra Club has written the Water Board pledging to fight any loosening of the 37-year-old discharge prohibition. Other groups will join that fight if the council votes to proceed with any project that allows storm water to reach the park. 

Tell the council you do not want storm water in the enclosed tidal ponds of Aquatic Park. Urge them to uphold the Water Board order prohibiting such discharges and to build projects that increase compliance with that order. Berkeley’s flood control improvements must be environmentally responsible, using pumps to increase pipe capacity, rather than polluting our regionally significant wildlife habitat. 

A one-way outbound gate at the park’s north end into the Strawberry Creek culvert could increase tidal flow in a way that does not change storm water discharges. Ask the City Council to develop such a low-harm project instead. Visit to read more. 


Mark Liolios is member of Aquatic Park EGRET.