- Reducing sediment to the lakes by from eroding banks, and
- Sanitary sewer upgrade
What if--during construction when so much soil is bare--we had a torrential downpour? Enough soil could erode and be dumped in the lake to equal twenty years of normal erosion--compared to if the Greenway hadn't been fixed.
To avoid this disaster, heroic measures for sediment control need to be employed during this project. I'll be discussing those plans in a posting soon.
Storm of June 21 at Edgewood Av
By looking at Edgewood construction, you can get some idea of what a storm can do. Edgewood Av is similar to our Greenway in that it has substantial slope.
The difference is that Edgewood Av has no basin above to gather stormwater. It's simply a hill, about two blocks from the top to the bottom. All the runoff comes from the rain that falls on the bare street.
In contrast, the Hillcrest-Upland Greenway has half a mile of basin above feeding into it. Moreover, rather than being a flat street, it has a V-shaped profile, concentrating the force of running water.
The storm shown here dumped 1.75" of rain. Storms of 7-10" are possible.
Edgewood Av, June 21. Photo by Jamie Saul. Click on photos to enlarge.
Above/below: Gullys in Edgewood Av. caused by the storm. Photos by Jon Standridge.
Sunset Village Creek during storm of June 21