Chesterfield information on Missouri River Conditions

Chesterfield officials are aware of and continue to monitor Missouri River conditions. The City uses the "Valley Watch-Warning" as developed for our emergency response plan to determine what actions are necessary at various river levels. THERE IS A LOT OF INFORMATION PROVIDED IN THIS E-MAIL, INCLUDING THE GRAPHICS PROVIDED BELOW. PLEASE REVIEW IT CAREFULLY.

AT THIS TIME, THE RIVER LEVELS ARE ACTUALLY BELOW FLOOD LEVEL AT THE ST. CHARLES GAUGE. ALTHOUGH WE ARE NOT TECHNICALLY IN THE VALLEY WATCH PHASE, WE ARE CAREFULLY MONITORING AND REVIEWING UPSTREAM CONDITIONS IN ORDER TO KEEP THE PUBLIC AS INFORMED AS POSSIBLE AND TO PROVIDE FACTUAL SOURCES OF INFORMATION AS WE MOVE FORWARD.

As you may have heard, the upper Missouri basin is experiencing extensive flooding. The Corps of Engineers, The Monarch-Chesterfield Levee District and the City of Chesterfield are aware of the discharge volumes from the upstream reservoirs and are continuously monitoring the levels of the Missouri River.

While our response system indicates that we monitor the Hermann gauge and the St. Charles gauge, we are viewing and monitoring gauges all the way back to the Gavin's Point Reservoir. Based on gauge readings taken this morning, river levels are trending up in Kansas City and points upstream. Gavin's Point has increased their discharge to 150,000 cubic feet per second, and that flow is included in the current river forecasts.

The observed gauge reading at Hermann this morning was 21.87 feet. The forecast is for the river to continue to trend down thru Thursday, and then begin increasing as the increase discharges upstream reach this gauge location.

This morning, the gauge at St. Charles read 24.72 and is also predicted to trend down thru Thursday, into Friday, and start to rise late Friday evening.
I've copied the latest Missouri River hydrographs below which show the recent and predicted gauge readings at the Kansas City, St. Charles and Herman Gauges. The graphics below give you a more visual indicator.

Based upon the increased discharge from Gavin's Point, and assuming normal rainfall in the watershed, the crest is modeled to a range between 32 and 37 feet at St. Charles. By way of perspective, the agricultural levee 2,000 feet north of the Monarch-Chesterfield levee would overtop somewhere between 33 and 34 on the St. Charles Gauge. Again, this is only the agricultural levee only, and is NOT the Monarch-Chesterfield Levee which protects the Chesterfield Valley.

We expect high water levels on the Missouri River for an extended period of time. The Corps advises that they intend to maintain the Gavin's Point discharge through the middle of August.

The current and forecasted river projections simply warrant our attention and are not a cause for alarm. However, I encourage all interested persons to subscribe to the City of Chesterfield's automated e-mail river condition updates. In doing so, you'll receive periodic updates and information relative to current river levels and forecasts. Our intent is to provide you with current, factual information. We do not intend to increase concern, nor do we want to re-assure you. We simply want to provide you with appropriate information and perspective.

For informational purposes only; NOT to compare or associate events;

The Great Flood of 1993 exceeded 40 feet at the St. Charles Gauge

Since 1993, the Monarch-Chesterfield Levee has been raised 5-8 feet depending on location, sand berms have been added, levee has been widened and access improved. The Monarch-Chesterfield Levee District indicates that the level of protection afforded by the CREST of the levee is between 47 and 48 on the St. Charles gauge.

For your convenience and information, I've copied text excerpts from our Valley Watch-Warning system which establishes the criteria for when we enter each phase of the response plan.

In the event the National Weather Service (NWS) projects a river surface level equal to or exceeding twenty-eight (28) feet at Herman, Missouri, a Valley Watch is initiated & the following actions are taken.

1. Valley Watch

a. During this phase, officials of the City of Chesterfield become aware of the possibility that the Missouri River may approach levels that would cause the implementation of this plan. Information about rainfall or snow cover melt within the Missouri River drainage basin will be considered.

b. The Director of Public Works monitors river stages and discharge forecast information released by the NWS and advises the Mayor, the Chief of Police, members of the Monarch-Chesterfield Levee District, and the St. Louis County Office of Emergency Management of river conditions.

c. The Chief of Police reviews the text of a prepared valley advisory announcement and makes appropriate modifications (telephone numbers, dates, etc.,) if necessary, and prepares contact lists for facsimile and manual distribution.

d. The City Administrator prepares accommodations for the installation of an adequate number of telephone lines, equipment and personnel should a Valley information hotline be activated.

e. The Monarch-Chesterfield Levee District reviews its relations and contacts with the contracted engineering firm.

f. The City of Chesterfield, Department of Public Works, makes visual inspections of the gate valve at Highway 40/61 to assess conditions.

g. Should the river rise to twenty-nine (29) feet at the Herman gauge, the City of Wildwood, Department of Public Works will make visual inspections and determine if the gate valve, located at the Monarch-Chesterfield Levee at Centaur Road should be closed.

2. Valley Advisory

a. River surface levels have reached or are protected to exceed thirty-four (34) feet at Herman, Missouri, or the water level at the Howell Island access road is within five (5) feet of the top of the Monarch Levee. Official statements regarding potential flooding conditions are delivered during this phase.

b. The Mayor issues a "valley advisory" statement to residents and business owners in the Valley. The advisory will be delivered from City Hall by means of a broadcast facsimile to those "on-line". Those residents not capable of receiving the facsimile broadcast will have a written advisory announcement delivered by a member of the Police Department. The advisory will remain in effect until it is upgraded to a warning or cancelled by official declaration.

c. A valley watch information hotline is prepared at City Hall. Equipment will be installed and the hours of operation and staffing assignments will be determined and verified.

d. Personnel are selected to function as public information officers, (individuals authorized to collect information, prepare and deliver official statements to the news media.)

e. The St. Louis County Office of Emergency Management prepares the emergency operations center at 14847 Olive Blvd. to accommodate Chesterfield City officials.

f. The Police Chief reproduces an adequate number of written "advisory statements" and delivers to individual residents that cannot receive the advisory by facsimile transmission. Additionally, a supply of the advisory sheets will be posted and stacked at business locations, which have walk-in clientele.

g. The Director of Public Works contacts the Corps of Engineers to begin a constant monitoring of river stages, discharge rates from Bagnel Dam, flow rates and projected crest dates.

h. The Director of Public Works, along with a member of Monarch-Chesterfield Levee District begin visual monitoring of levee system structures to include the levee and all closure instruments.

i. The Director of Public Works evaluates inventory of City owned, non-expendable equipment, such as pumps, generators, boats and motors. Contact is made with surrounding jurisdictions, as well as with the Corps of Engineers, Kansas City District, to determine the availability of like equipment and/or other necessary supplies.

j. Should the river rise to thirty-four (34) feet at the Herman gauge, the St. Louis County Department of Highways and Traffic will conduct visual inspections and determine if the flood gate, located on the St. Louis Southwestern Railroad at Centaur Road, should be closed.

k. The Valley "advisory statement" will remain in effect until the river surface level drops to thirty-five (35) feet at St. Charles with projected forecasts indicating falling river levels.

l. On an "as needed basis," the Director of Public Works activates any mutual aid agreements established to assist in the procurement of equipment and supplies necessary to maintain pumping operations to remove river water seepage or rainwater pooling from within the Valley.

3. Valley Warning

In the event river surface levels have reached or are projected to
exceed thirty-six (36) feet at Herman, Missouri, or the water level at the Howell Island access road is within three (3) feet of the top of the Monarch-Chesterfield Levee a Valley Warning is initiated and the following actions occur:

a. Official actions are initiated and emergency conditions are assumed.

b. The Mayor of the City of Chesterfield issues a "V alley Warning" statement to residents and business owners in the Valley.

c. The Mayor/City Administrator will begin a process of providing daily briefings to local residents, business owners, and the news media at designated times. Representatives from the Police Department and Department of Public Works will be available to assist in conveying appropriate information.

d. The "Valley Warning" will remain in effect until a river surface level of thirty-seven (37) feet at St. Charles with projected forecasts indicating falling river levels, or has dropped to three (3) feet or more below the top of the levee throughout the Monarch-Chesterfield Levee.