| Historic Delta Island Inundation records & maps: | |
Ryer Island has not flooded since the levees
were improved to their current standard, after 1910.
Historical records indicate Ryer Island did flood in 1904 and
1907,
BEFORE the current levee was built. Yet the
Delta Risk Management Strategy,
Phase 1 report, or DRMS, a VERY important document currently
being used to make decisions regarding the future of the Delta,
lists Ryer Island as being inundated "3-5" times in the last 100
years. Ryer Island has flooded ZERO times in the last 100
years. This is an important number because calculations
regarding levee failure risk, seismic risk, levee and island
salvageability and land valuation all take into consideration flood
risk factors. Click on thumbnail to compare DRMS inundation
map to correct historical map.DRMS was published in "final" form by California's Department of Water Resources (DWR) to validate decisions regarding the future of the Delta, but the underlying historical data regarding Ryer Island is clearly wrong as to inundation history, including data provided in Sections 2,4,7,9,12,13 and other reference documents. . DRMSf1_wrong_on_Ryer.pdf or see List of DRMS mistakes. DRMS has been used for the decision process leading up to and including the Bay Delta Conservation Plan (BDCP). As of October 2009 DWR representatives had acknowledged the use of incorrect data regarding Ryer Island and had agreed to notify the consultant companies who drafted the report (URS and Benjamin & Associates) of the mistake, so that corrections could be expidited. In October 2009, after repeated requests for review and correction, DWR representatives confirmed the incorrect data use regarding Ryer Island, and agreed to contact their consultants who did the report, to get it corrected. However, on 11-18-09 DWR responded again by email, indicating there isn't sufficient funding to correct DRMS Phase 1, so a request has been made to remove the entire DRMS Phase 1 report from any new DWR reports, such as the California Water Plan Update 2009. See Request Click on the thumbnail below to see copy of email One possible but not likely explanation...there are TWO "Ryer Islands" in Solano County! Ryer Island (aka Long Point Island) in the Suisun Bay is well within the 100 year flood zone and has a history of flooding. Its basically an unoccupied island. Ryer Island, bordered by Steamboat and Cache Sloughs, is an occupied island and has NOT flooded since the levees were improved after the 1907 flood. However, Department of Water Resources (DWR) reports, such as DRMS and the "Risks and Options to Reduce Risks to Fishery and Water Supply Uses of the Sacramento/San Joaquin Delta" (DWR & DFG, 2008) use incorrect flood history for Ryer Island. The underlying data for island inundation is in turn used to make assessments regarding individual island seismic risk, flood probability, and can affect valuation. Therefore, using correct island date is imperative for these calculations. Click on the links provided on this page for some pdf's showing sections of the noted reports. You can also see maps and documents regarding Ryer Island at the Maps & Docs page. Click on the maps or photos below of Ryer-Long Point Island. Then look at the map for Ryer Island by Steamboat Slough. Not in the 100 year flood plain! This may be one reason why DWR reports, like DRMS, are providing INCORRECT data regarding Ryer Island inundation (flood) history. Using a higher number of flood incidents negatively affects the outcome of reports regarding Ryer, including seismic risk, flood risk, and the "save or don't save" assessments by proponents of the BDCP. In 2008 DWR representatives were notified of the conflict in names and incorrect data being used. |
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Updated 10-15-09: Click on email copy to the left for communication verifying the DRMS data regarding Ryer Island was incorrect and will be corrected...finally! |
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Updated 10-21-09: Click on email copy to left for DWR communication verifying DWR records regarding Floods and Ryer Island. |
![]() View of the occupied Ryer Island |
Links to reports
using incorrect Ryer Island data: Timeline of mistakes in reports regarding Ryer Island: DWR-DRMS 2009 DRMS Phase 1: Section 13-incorrect Ryer Island Information on map towards end of report. http://www.waterboards.ca.gov/waterrights/water_issues/programs/bay_delta/strategic_plan/comments/080319_strwp_dwr_ab1200report.pdf |
![]() View of the uninhabited Ryer Island from Google Earth |
100 Year-FEMA vs 2007 DWR map |
FEMA Flood Map![]() |
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