By Kevin Hong
Kevin the intern here!
On Saturday, March 16th, we gathered next to the Lake Chalet restaurant to begin our walk led by Joel Peter, the Measure DD Program Manager for the City of Oakland. Our walk took us through areas that have gone through development, are being developed, and will be developed as the city progresses with the program.
So what is the Measure DD program?
It’s a $198.25 million bond measure that was passed by an 88% public vote in 2002, aimed at improvements to Lake Merritt, the estuary, and watershed health. Notable improvements include the renovation of Studio One, a new rec center in the city, creek restoration, and new sidewalk.
The program will close gaps in trails in the area, as well as introduce new measures to treat urban runoff before it reaches the lake – pretty important, since all the water that enters storm drains in the 4,650+ acres that make up our local watershed eventually flows into Lake Merritt.
We started in the parking lot at the Lake Chalet, where Joel told us how Measure DD affected the immediate area: around the lake, traffic was moved away from the edges of the lake, and the space left in between saw various improvements to help the lake deal with urban runoff.
Bioswales, like this one in front of the Lake Chalet, collect urban runoff before it flows into the lake. The water enters the swale through slots in the curb, then the sedges and other water-loving plants absorb much of the runoff. As the water passes through the swale, pollutants are combed out by the vegetation before entering a percolated pipe and moving into the lake.
This green roof on the waste building of the Lake Chalet. Joel maintains it himself! Notable plants: sedge, taro, red fescue, and many weeds. Underneath the bed, there are perforated pipes that irrigate it from underneath on a regular basis.
Joel shows us the absorbing power of the permeable pavement used in the aisle near the Lake Chalet. Permeable pavement is like regular pavement, but without the sand mixed in. It collects water in the spaces where sand usually fills, serving as a reservoir of sorts. There are pipes around and underneath that transport water to the lake when the water levels run over the pavement’s capacity.
Joel shows us one idea they had: instead of simply elongating a pipe previously underground, they exposed the water that moved through it, creating a sort of storm water “creek”, vegetated with sedges, that absorbs and cleans the water that passes through. On the downstream end is a pipe that drains into the lake.
Here, Joel tells us about two trash filters, (this one’s on the corner of 12th and Merritt) housed in underground vaults and incorporated into the pipes that drain into the lake. A marvel of modern engineering, the huge filters are designed so that the water entering swirls around inside. This centrifugal movement passes through a steel grill that separates litter from the flow, casing the trash to float to the top where large vacuum trucks remove the debris and cart it off to a landfill.
Thanks to Oakland’s ban on Styrofoam containers and the Alameda County ban on plastic bags, there’s far less of this kind of trash in the lake.
As we walked southward toward the pump station, Joel told us about the history of the dam that used to exist over the south end of the Lake on 12th street. Lake Merritt is connected to the bay, so it experiences significant tidal flow. Samuel Merritt, when mayor of Oakland, proposed the building of the dam to keep water IN – partly because low tide stank, as people were dumping sewage into the lake. The dam used to be narrow, but the city kept widening it. Eventually, 12th street was built over the dam.
In the 1950s, the miniway and dam were no longer structurally stable, and the construct was torn down. With federal spending, the city’s been able to construct a new overlook over the now-exposed channel, with a bridge spanning across. This 100 ft wide channel, along with coming improvements of Measure DD, will remove bottlenecks in the water and increase tidal flow.
Joel addressed aesthetic concerns over the exposed mudflats. They may appear ugly, but they’re full of life! They’re populated by clams and tube worms, algae and seaweed use them as bases for growth, and they’re feeding grounds for the wading birds.
After we tramped across the new overlook, which features several walkways and a small amphitheater-like area, our walk took us under and beyond the 12th street bridge. We got to see an area behind the bridge that’s being constructed into a new tidal marsh. It’s about two thirds of an acre in area, and will be planted with local marsh plants from Oakland and Berkeley nurseries.
Local stock of cordgrass, pickleweed, monkey flower, and willows will be among the fauna inhabitants- using plants that have localized genetics will help them thrive in these areas with minimal human maintenance. Hopefully, it will also help attract more natural inhabitants of the lake.
We crossed the street and walked past Laney College to the 7th street pump station. The station is equipped with gates, the main mechanisms for controlling tide and water level in Lake Merritt. Its pumps, though capable of moving thousands of gallons of water per minute, aren’t used often (as a matter of cost-efficiency) but are effective in stopping high tides formed by unexpected storms.
Fun fact: Bat rays are a common sight on the bay side of the pump station, gathering at the trash grate. They can be found in the lake as well, presumably slipping in sideways through the trash bars or coming in as small juveniles.
As part of the Measure DD program, a small water channel and pedestrian walkway will be added to the side of the station. The last culvert will also be removed, thus allowing small crafts like canoes and kayaks access to the bay from Lake Merritt.
Thanks to Joel Peter for leading this walk, to Dan Schwartz and Damon Tighe for photos, and to everybody who attended!
See you soon!