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Home My WebLink AboutVIII-17 Update on Flood Forecast & Response Planning Steps City Council Memorandum To: Mayor Fasbender & City Councilmembers From: Ryan Stempski – Public Works Director/City Engineer Date: March 29, 2023 Item: Update on Flood Forecast & Response Planning Steps Council Action Requested: No action requested. Council is being provided an update to the flood fighting policy. City forces would provide sand, sandbags, logistical support, and hauling of filled sandbags to curbside locations, but City forces will not be used to fill sandbags or to build barriers on private property. After the flood, City forces will haul away all sandbags that are brought back out to the curb. Background Information: City staff monitors the National Weather Service (NWS) forecasts for the Mississippi River at Lock and Dam 2 extremely close during the spring snowmelt. Predictions show that we may be a couple weeks out from the highest stage potential, at which there is a 50-75% chance of a moderate flood stage (17 feet). Please see the chart below for the NWS projections as of March 20th. VIII-17 This forecast needs to be qualified – many variables can significantly change the forecast higher or lower, including how rapidly the snowmelt occurs, how quickly the frost comes out of the ground, and additional snowfall or rainfall events. Over the next few weeks, the forecast can and will change. It is also important to note that the NWS’s forecasts do lean conservative, and our observations over the years are that actual flood stage has ended up being slightly below the forecasted figure made closest to the crest. Physical Impact It would take a flood stage of 22 feet to directly impact approximately 10 homes on the north side of 1st Street in East Hastings. Many of these homes have not sandbagged in the past when flooding occurred. Therefore, it would be prudent to continue to monitor the flood projections and reach out to the impacted properties in advance of potential sandbagging efforts. There are also a number of public infrastructure impacts that would occur based on the current forecast, including closure of several segments of City roadways, closure of spaces within Jaycee, Lake Rebecca, River Flats, and Levee Parks. Attached is a two-page summary covering notable City and private property locations where impacts may be observed. Also attached, are maps of these locations and stages. City Response As flood levels rise, Public Works, Parks, Police and Fire will coordinate efforts and close roadways, trails and parks as appropriate. We will monitor river levels and flood forecasts. City staff has engaged in preliminary discussions with the Branchline Church, which would allow the use of their facilities (east of the railroad tracks off 2nd Street) to stage equipment and materials for sandbagging efforts. Members of the church and other volunteer groups would be invited to sandbag homes where that was requested. As in the past, City staff proposes to support those efforts by supplying sand, sandbags, and poly sheeting needed to sandbag homes, and to haul sandbags filled by volunteers to curbside locations where they can be accessed by volunteers to construct barriers on private property. In addition, flood update and planning meetings will be scheduled, with the frequency of the meetings dictated by flood forecasts and planning flood fighting needs. Financial Impact: The financial impact of flood fighting activities is unknown; dependent on level of flooding experienced and the demand for sandbags by the aforementioned property owners. We have sandbags, poly, and pallets on hand already. If flooding becomes severe, there is a good possibility that emergency declarations could be made and that certain flood response efforts and public infrastructure damage would be eligible for State and/or Federal reimbursement. We have identified a flooding account number to track expenses for reimbursement if financial assistance becomes available. Attachments:  General Flood Information Notes  General Flood Maps VIII-17 General Flood Information Notes UPDATED March 2019 National Weather Service Flood Information Website: http://water.weather.gov/ahps2/hydrograph.php?wfo=mpx&gage=hstm5 Important Elevations – City Infrastructure Base Elevation of River is 670.65’ STAGE ELEVATION DESCRIPTION 15.00 685.65 Top of Steps & Veterans Memorial - Levee Park 15.35 686.00 Low Point - Mississippi River Trail by Levee Park steps 15.54 686.19 Low Point – Spiral View Loop Road (north side of river beneath Highway 61 Bridge) 15.80 686.45 Low Point – E 10th Street/County Road 54 (just east of 18th Street intersection) 15.95 686.60 Low Point - 1st St/RR Bridge Underpass – Water on Rd 16.90 687.55 Low Point E 4th St. – Water on Road 17.05 687.70 Low Point – E 10th Street – ½ way between Vermillion River bridge and E 18th Street 17.25 687.90 Low Point – E 10th Street just west of E 18th Street 17.35 688.00 Top of Riprap - Jaycee Park 18.43 689.08 Low Point - L/D Road 18.55 689.20 Bottom of Flood Columns – Levee Park 18.85 689.50 Low Beam – E 4th St. Bridge 19.35 690.00 Low Point – E 1st St & Franklin 19.35 690.00 Lake Isabel Boat Ramp Parking Lot (lowest areas) 19.85 690.50 Front Deck Hydropower Plant 20.95 691.60 Floor of Musical Playground 21.15 691.80 Floor of Rotary Pavilion 22.35 693.00 Top of Deck – E 4th St. Bridge, and HASTINGS Sign – Levee Park 22.45 693.10 Labyrinth slab – Levee Park 23.00 693.65 Patio/Fireplace – Levee Park 23.45 694.10 Top of Lock Wall – Hydro-electric Plant Access Estimated Flood Impact on 1st St. Homes from GIS Contours: Based on 2013 GIS Elevation Data and 6/23/2014 Field Surveys - * indicates approximate elevations STAGE (FEET) ADDRESS/OWNER LAST NAME LOWEST STRUCTURE OPENING ELEVATION 17.70 623 1st Street East - Mollick 688.35 – Door on NE side of home 18.19 607 1st Street East - Latch 688.84 – Rear door 18.09 613 1st Street East – Whelan 688.74 – rear door 18.50 1115 1st Street East – Plan 689.15 – Cellar Door at rear of home 18.96 801 1st Street East – Biscoe/Wiegele 689.61 18.86/19.1 707 1st Street East - Heselton 689.51 – Garage/Outbuilding, 689.75 - House 20.07 1021 1st Street East – Leslie 690.72 – Chimney flue door 20.47 1015 1st Street East – Carl 691.12 – E side entry door 20.56/21.38 803 1st Street East - Wiegele 691.21 – Garage, 692.03 - House 21.35 817 1st Street East – Machinery Consultants 692* 22.35 1111 1st Street East – Plan 693* 23.35 1001 1st Street East – Reuter 694* 23.55 803 1st Street E – Flaten 694.2 24.35 901 1st Street East - Gear 695* 24.35+ Properties at E end of E 4th Street 695+ **There are also a couple of low areas in yard spaces on the south side of 1st Street E which can become inundated by way of the City’s storm sewer connection. These are located at the properties of 914 E 1st Street and 109 Washington Street. VIII-17 General Flood Information Notes UPDATED March 2019 Recent Crests (1) 16.60 ft on 07/01/2018 (P) (2) 17.50 ft on 05/01/2018 (P) (3) 15.19 ft on 10/13/2017 (4) 15.22 ft on 05/27/2017 (5) 15.85 ft on 07/18/2016 (6) 12.87 ft on 05/23/2015 (7) 18.95 ft on 06/27/2014 (8) 14.35 ft on 07/02/2013 (9) 15.07 ft on 06/02/2012 (10) 17.76 ft on 04/13/2011 (11) 17.42 ft on 03/30/2011 (12) 16.22 ft on 10/04/2010 (13) 17.22 ft on 03/25/2010 (P) (14) 22.00 ft on 04/29/2001 (15) 21.60 ft on 04/17/2001 (16) 21.30 ft on 04/13/1997 (17) 18.90 ft on 06/28/1993 (18) 16.90 ft on 04/07/1986 (19) 17.10 ft on 05/04/1975 (20) 15.10 ft on 07/29/1972 (P): Preliminary values subject to further review. Historic Crests (1) 25.90 ft on 04/17/1965 (2) 24.30 ft on 04/16/1969 (3) 22.00 ft on 04/29/2001 (4) 21.60 ft on 04/17/2001 (5) 21.30 ft on 04/13/1997 (6) 20.90 ft on 04/16/1952 (7) 18.95 ft on 06/27/2014 (8) 18.90 ft on 06/28/1993 (9) 18.90 ft on 04/18/1951 (10) 17.76 ft on 04/13/2011 (11) 17.50 ft on 05/01/2018 (P) (12) 17.42 ft on 03/30/2011 (13) 17.22 ft on 03/25/2010 (P) (14) 17.10 ft on 05/04/1975 (15) 16.90 ft on 04/07/1986 (16) 16.60 ft on 07/01/2018 (P) (17) 16.60 ft on 06/30/1957 (18) 16.22 ft on 10/04/2010 (19) 15.85 ft on 07/18/2016 (20) 15.50 ft on 05/11/1950 (26) 12.87 ft on 05/23/2015 (P): Preliminary values subject to further review. VIII-17 H i g h w a y 6 1 USACOE Lock & Dam No. 2 &City of Hasitngs Hydro-Electric PlantNo Damages Expected to City FacilitiesCity will fill USACOE Septic Tank with freshwater to avert failure/collapse under floodwaters City of Hastings - Lock & Dam RoadModerate to Heavy Road Flooding ExpectedMinor Road Damage PossibleModerate Debris Cleanup Expected City of Hastings - Lake Rebecca ParkParking Lot & Park Grounds FloodingMinor Pavement Damages ExpectedMinor Debris Cleanup Expected City of Hastings/Minnesota DNR - Public Boat RampComplete Flooding and Closure of Ramp ExpectedSignificant Flooding of Parking Area PossibleRamp Damage PossibleModerate to Significant Debris Cleanup Expected City of Hastings - Lock & Dam RoadSignificant Road Flooding ExpectedModerate to Significant Debris Cleanup ExpectedMinor to Moderate Road Damages Possible City of Hastings - Levee ParkSignificant Flooding of Park Grounds expectedMinor to moderate damage of park features possibleModerate to significant debris cleanup expected City of Hastings - E 1st Street Underpass of CP Rail BridgeClosure Required at Stage of 16 FeetMinor Road Damages PossibleModerate Debris Cleanup Expected Residences on E 1st Street(607-1115 E 1st Street)Moderate to Significant Structural Flooding PossibleCity Coordintates with Property Owners & Volunteers to ProtectStructures as RequestedHomeowners Provide Own Post-Flood Cleanup As Necessary City of Hastings - East Hastings Sanitary Lift StationNo Damages Expected City of Hastings - E 4th StreetSignificant Road Flooding ExpectedAlternate Access Available to Homes at East End (Dirt Roadin wooded area)Minor Road Damage PossibleMinor Debris Cleanup Expected Highway 55 City of Hastings - Lake Isabel Boat RampClosure ExpectedNo Damages ExpectedMinor Debris Cleanup Expected City of Hastings - Riverfront Trail & Scenic OverlookMinor Flooding & Damages PossibleModerate Debris Cleanup Expected City of Hastings - E 4th Street BridgeClosure Possible at 22 Feet StageNo Vehicular Access to Private Propertyfor City services Private Homes - all are at or aboveelevation of 695 feet (stage of 24.35) Private Home is at elevationof 693 or higher (Stage of 22.35) City of Hastings - Spiral View Loop RoadClosure Required at Stage of 15.5 FeetSignificant Flooding of Road ExpectedMinor to Moderate Damages PossibleModerate Debris Cleanup Expected E 1st Street E 4th Street 2019 Mississippi River Flooding - Areas of ConcernNotes based on NWS Probabilities Forecast Dated 3/4/2019 VIII-17 City of Hastings - Lock & Dam RoadSignificant Road Flooding ExpectedModerate to Significant Debris Cleanup ExpectedMinor to Moderate Road Damages Possible City of Hastings - Levee ParkSignificant Flooding of Park Grounds expectedMinor to moderate damage of park features possibleModerate to significant debris cleanup expected City of Hastings - East Hastings Sanitary Lift StationNo Damages Expected City of Hastings - E 4th StreetSignificant Road Flooding ExpectedAlternate Access Available to Homes at East End (Dirt Roadin wooded area)Minor Road Damage PossibleMinor Debris Cleanup Expected Dakota County State Aid Highway 54 (Ravenna Trail)Moderate Flooding of Roadway Possible just east of E 18th StreetMinor Damage to Roadway PossibleClosure Necessary at stage of approx. 18.5-19 feetMinor Debris Cleanup Expected City of Hastings - E 10th StreetMinor to Moderate Flooding of Road ExpectedClosure Expected to be necessary eastof Progress Drive City of Hastings - E 18th StreetMinor Flooding ExpectedClosure may be required Highway 55 City of Hastings - Lake Isabel Boat RampClosure ExpectedNo Damages ExpectedMinor Debris Cleanup Expected City of Hastings - E 4th Street BridgeClosure Possible at 22 Feet StageNo Vehicular Access to Private Propertyfor City services Private Homes - all are at or aboveelevation of 695 feet (stage of 24.35) Private Home is at elevationof 693 or higher (Stage of 22.35) City of Hastings Public Works1225 Progress DriveNo Impact Dakota County Road 91 (Glendale Road)Flooding of Road Not Expected H i g h w a y 6 1 Hig h w ay 316 Spiral Boulevard G l e n d a l e R o a d E 10th Street CSAH 54 (Ravenna Trail) 2019 Mississippi River Flooding - Areas of ConcernNotes based on NWS Probabilities Forecast Dated 3/4/2019 VIII-17