The Stormwater Subcommittee, along with representatives from Burke Engineering and V3 Engineering, reviewed Burke's responses to V3's initial findings, including Burke's idea of potentially constructing a berm along the south side of York Commons to ensure water will always be directed to the west and away from the homes along Cayuga Avenue.
Discussion ensued regarding City policy for new construction and existing home additions that was reviewed by the City on July 7, 2014, as well as details of how an Intergovernmental Agreement might be structured with detailed requirements for each site being separate.
It was agreed that Burke would take the engineering from its current 5% completion up to the 15-20% level in order to provide more detailed plans.
Although York Commons has been selected as the City's first priority, discussion centered around making progress on all sites along the way.
Discussion also took place concerning variable speed drives at the City's pump stations along Salt Creek, increasing the capacity of pump stations and examining the potential of utilizing the Eldridge southwest reservoir as part of the macro solution.
The Park District sent an email request after the meeting, per Greg Wolterstorff of V3 Engineering, asking that Burke Engineering provide the technical data summarized for each park site. Since York Commons is the first site that we intend to review based on The City's prioritization of these potential flood control projects, the York Commons data set can be provided first, unless all park designs are available already. Here is the information the Park District requested:
- General statement regarding the potential for sanitary sewage discharge to be combined with storm flows that may enter each park.
- Invert elevations for all storm sewer inflow/outflow locations from the park sites.
- Pipe sizes for all storm sewers throughout the park sites. Protection elevation and storm event that bypasses the park sites (i.e.. - How high does the water get in the adjacent storm sewer inflow, and what storm event goes right by the site?)
- Peak elevation and critical duration storm event which occurs within the park sites.
- Draw down durations and plotted hydrographs for the peak critical duration storm event and for the 2( 24 Hour-100 Year storm event.
- Conceptual engineering for the field bottoms which show proposed storm sewer routing, proposed bottom spot elevations and slopes, and likely under drain locations, elevations and storm sewer connections.
This additional information will increase the confidence level of the observations made by V3 Engineering prior to their presentation to the Park Board about flooding impacts to the park sites, and answer questions regarding playability, maintenance and other associated concerns.
