Stormwater Task Force

City of Falls Church Department of Public Works Stormwater Task Force Minutes: Meeting #2 Date: Thursday, January 30, 2020 Time: 7:00 PM Room: Council Chambers Location: Falls Church City Hall 300 Park Avenue, Falls Church, VA 22046 I. Call to Order The meeting was called to order at 7:00 PM by Mike Domenica, City Liaison to the Task Force II. Attendees Task Force Members: Rolf Anderson, David Deitch, Dave Gustafson, Ellen Heather, Jeff Jardine, Hans Miller, Lauren Pinkus, Matthew Ries City Staff: Wyatt Shields/City Manager, Michael Whitfield/Director, Department of Public Works, Alan Dalton/Senior Engineer, Mike Domenica/Task Force Liaison for City III. Approval of Minutes of Previous Meeting The minutes of the previous meeting were approved without change IV. Discussion and Decisions 1. There was a discussion of the need for and election of a Chairperson. Dave Gustafson was nominated, seconded and elected as Chairperson of the Task Force. 2. The Task Force discussed the site visits with each members volunteering their impressions / comments. Mike Domenica stated that the “Trammel Branch” project had been re-named “West Columbia” so that all projects were consistently identified by street names. 3. A brief discussion of each project ensued with a description of the proposed improvements and preliminary cost estimates. The West Columbia project was discussed in greater detail before it was decided that we needed to move to other projects due to time constraints. The items discussed for West Columbia project included: a. A link between sanitary sewage overflows and stormwater issues (I&I). 1  b. A discussion of the existing private obstructions (bridges, driveways, walls, etc.) within the drainageway. c. A discussion of the “dry pipe” that could be added to the W&OD widening and possible “daylighting” of the outfall. 4. The other projects were discussed in lesser depth with some general discussion including a request for the map showing where sanitary sewers have been relined (8/7/19 Town Hall meeting exhibit and also included with the CIP Budget presentation). The GKY Project Information Sheets were presented/reviewed. There was also a discussion as to the possibility of the City buying houses that are flooded versus constructing projects that would have minor (10 year storm) benefits for drainage but would not solve flooding for larger events. The two small projects were added to the discussion with Mike Domenica stating that the Laura/Poplar Drive project would, if moved forward, require replacement of the existing 15 in. corrugated metal pipe due to its condition as determined through TV inspection. Regarding the Lincoln Ave. – West project, the flooding of the yard and ground- floor level of the house is due primarily to the elevation of the house and basement and that there was not much that could be done for this site. The surface grate inlet in the rear of the house, serving multiple homes, ids intended to discharge to the conduit adjacent to the W&OD Trail, but the hydraulic head between the water surface at the grate and the water elevation in the W&OD conduit appears to be very low, negating options for discharge to the W&OD conduit during periods of significant pipe flow. 5. The group discussed draft evaluation criteria and methodologies for assigning ranking rates. It was suggested that a coarser scoring range, say 1 to 3 rather than 1 to 10, be used. 6. Potential outfall issues with Fairfax / Arlington were discussed along with the design criteria for frequency of flooding (10 year event except possibly for West Columbia / Trammel Branch). 7. The opportunity for public input and public hearings to obtain frequency of flood damage and other information on the respective projects was discussed. It was decided that the Task Force members would conduct door-to-door assessment in their areas. Ms. Pinkus volunteered to develop a questionnaire/survey questions. (Note: This questionnaire was drafted by Ms. Pinkus, circulated to the team for review, modified accordingly and sent to the Task Force members to use in their neighborhoods. 8. The group asked if there was a stormwater model for the entire City and the 2007 C.O.E. The “StormCad” model used by the Corps and report was discussed. The report/model is located at P:\PUBLIC WORKS\STORMWATER\Reports and Studies\2007 COE Stormwater Assessment. 9. The City’s Chesapeake Bay Act was discussed along with any impacts of the projects on the RPA. The only project that would impact the RPA, at this time is the West Columbia/Trammel Branch project, with a possible minor impact for a potential East. Jefferson outfall pipe. 2  10. Flood Insurance rates and potential actions that the City might take to reduce the rates were discussed. The City has a CRS rate of 6 and no municipality in Virginia has a lower rate. In order to lower the rate beyond 6, we will need to map our floodplains at a smaller threshold for tributary area (we currently use FEMA 1 square mile scale) and start to remove homes from the floodplain. The smaller tributary area would add homes to the floodplain. 11. A brief discussion of the C.I.P. budget was led by Mike Domenica, with the note that the construction costs were “place holders”, until the preliminary designs were completed, Task Force ranking/recommendations finished, and approval by the City Council obtained. 12. Internal email communication with the Task Force was discussed. Wyatt Shields advised that the Task Force was a “public body” and that all deliberations must be open to the public. Any meetings of more than two Task Force members would be considered a public meeting and would need to meet public meeting laws of the state and city. No more than two Task Force members can communicate by e-mail at any time and all communications should copy Mike Domenica. V. Next Meeting Dates Dates on which Task Force members could attend the next three task force meetings were discussed. It was suggested that Mike Domenica send to the Task Force a list of potential dates from which the best dates could be selected. VI. Adjournment The meeting was adjourned at 9:10 PM 3