Upper Prairie Silver Moores
Project History
With work beginning over 15 years ago, the Upper Prairie Silver Moores Project highlights a sustained effort to reduce flooding in Grand Island.
2004
Feasibility Study is Completed
CPNRD and the City of Grand Island complete a feasibility study to provide flood risk reduction (reduce flood damages) from 1% AEP (Annual Exceedance Probability), commonly called a 100-year flood, to urban, residential and commercial properties in northwest Grand Island.
2005
Grand Island and Hall County Hit with Millions in Flood Damages
On May 11, 2005, nearly 3,000 homes and business are damaged by flooding, many of which would have seen reduced damage levels had the UPSM Project been in place. Grand Island sustained $3-5 million in damages, while Hall County sustained $12-15 million in damages.
Funding Secured for Project
CPNRD, the City of Grand Island and the Nebraska Natural Resources Commission were the major funding partners for this project. JEO Consulting Group was hired for the design and construction of the project in October 2005.
2007
Construction Begins on the Detention Cell
The first two phases of the detention cell begin construction, including areas on both the east and west sides of Dannenbrog Road.
2010
Construction Halted on the Detention Cell
Upon completion of the fourth phase, construction was halted by the United States Corps of Engineers (USACE) due to concerns with unexploded ordinances on the adjacent USACE property.
2013
Construction of the Dry Dams PCUL4 and DCUL6 Begins
The two smallest dams began construction in 2013, with completion in 2014.
2015
CPNRD Receives Clearance from USACE to Proceed with Detention Cell Construction
The NRD received clearance from USACE in 2015 that the risk posed by unexploded ordinances on the adjacent property had been remediated and construction of the detention cells could continue.
Construction of the Dry Dams PCUL1 and PCUL2 Begins
The two largest dams began construction in 2015, with completion in 2016.
CPNRD Begins Development of Conditional Letter of Map Revision (CLOMR) for FEMA
CPNRD hires JEO Consulting Group Inc. to begin work on the CLOMR submission for FEMA. This letter was a critical step to ensure final flood map revisions are approved by FEMA.
2016
CPNRD Submitted a Conditional Letter of Map Revision (CLOMR) to FEMA
This application is the first step of the remapping process. A CLOMR gives preliminary confirmation that map changes can occur once construction of the project is complete, assuming no changes to design have been made.
2018
Conditional Letter of Mapping Revision Approved by FEMA
Approval of the CLOMR was received in summer of 2018. The CLOMR is essential to the floodplain map revision process as it provides assurance that FEMA will accept the technical information necessary to update the floodplain maps when the LOMR is submitted. It is anticipated that the LOMR request will be submitted to FEMA in early spring of 2019.
Construction of the Levee Begins
Construction began in the fall of 2018 on the final structural component of the UPSM project. Construction is mostly complete and is expected to be wrapped up in the spring of 2019.
2019
Historic Spring Flooding
Because of the work done with the Upper Prairie Silver Moores Project, the Grand Island area was able to remain largely untouched. An estimated $47 million in damages was avoided during this event; reduced flooding risk for approximately 791 homes and businesses; and established more than 14,500 acres of agricultural ground with reduced flooding risk.
Implementation of Flood Control System
CPNRD intends to install remote monitoring equipment at select locations in the watershed to monitor levels in dams and the detention cell, along with collecting photos and rainfall data during flood events.
Flood Control Stroll
To create lasting community awareness of flood mitigation, the CPNRD partnered with local businesses, artists, and music festival Hear Grand Island to create an interactive educational experience dedicated to flood safety, flood mitigation, and spreading the concept of residual risk. The event included six stops with six questions about flood mitigation and safety. When attendees visited all stops and answered the questions, they were entered to win raffles from local businesses and museums. More information can be found here.
Construction Completed
All construction for flood risk reduction infrastructure in the Upper Prairie Silver Moores Project was completed during summer 2019.
2020
Approval of LOMR
FEMA approved the CPNRD’s letter of map revision (LOMR), effective September 25, 2020. Approximately 600 properties were removed from the 100-year floodplain, as shown on the effective FIRM, with an estimated $500,000 - $1 million* annual flood insurance premium cost reduction benefits.
*Estimated based on number of properties removed from the floodplain by the LOMR and assumed coverage amounts - actual amounts will vary on a property-by-property basis.