Iowa DNR Dam Inspection Report

• Dam Name

• Dam inventory number

• Conducted on

  Date

• Inspector

  Select Paige Adams Casey Welty Jon Garton

  • Paige Adams
  • Casey Welty
  • Jon Garton

• Others present:

• If there are changes in ownership or contact info, note it here.

Field Conditions

• Pool Level

  Normal Pool (+/- 6 inches)

  Dry Dam

  Other

• Describe water level

• Ground Moisture Condition

  Dry

  Wet

• Any changes in downstream land use that may impact hazard classification of dam?

  No

  Yes

  N/A

Upstream Slope

• Slope appears too steep?

  No

  Yes

  N/A

• Slope has poor vegetative cover?

  No

  Yes

  N/A

• Slope contains trees and/or brush?

  No

  Yes

  N/A

• Cracks on the embankment slope?

  No

  Yes

  N/A

• Wave erosion at the water line?

  No

  Yes

  N/A

• Embankment has sinkholes, depressions, slides, or bulges?

  No

  Yes

  N/A

• Animal burrows on the embankment?

  No

  Yes

  N/A

• Upstream Slope General Notes

• Photo of Upstream Slope

  Media

• Sketch

  Drawing

Top of Dam

• Cracks, unusual settlement, or sinkholes along the top of dam?

  No

  Yes

  N/A

• Is the top width uniform and adequate?

  Yes

  No

  N/A

• General Notes:

• Photo of Top of Dam

  Media

Downstream Slope

• Slope appears too steep?

  No

  Yes

  N/A

• Slope has poor vegetative cover?

  No

  Yes

  N/A

• Slope contains trees and/or brush?

  No

  Yes

  N/A

• Embankment has sinkholes, depressions, slides, or bulges?

  No

  Yes

  N/A

• Cracks on the embankment slope?

  No

  Yes

  N/A

• Animal burrows on the embankment?

  No

  Yes

  N/A

• General Notes

• Downstream Slope Photo

  Media

• Sketch

  Drawing

Internal Drainage and Seepage

• Does the dam have internal embankment drains?

  Yes

  No

  Unknown

• Description

• Outlets were observed and in good condition?

  Yes

  No

  N/A

• Estimated flow from drains (describe each drain separately):

• Photo(s) of outlets.

  Media

• Was seepage observed through the embankment outside of designated drains?

  No

  Yes

• The seepage appeared clear with no signs of ongoing internal erosion.

  Yes

  No

  Unknown

• Immediate Action is Required at the Dam! The Emergency Action Plan should be activated if there is one in place. If no EAP, the Emergency Manager may need to be alerted and the dam put on a monitoring schedule.

• Describe location and extent of seepage.

• Seepage photos

  Media

• Sketch of seepage location

  Drawing

• General Internal Drainage and Seepage Notes:

• Description of spillway

• Is the inlet free from debris?

  Yes

  No

  N/A

• Are there trees and brush around the inlet?

  No

  Yes

  N/A

• Inlet photos

  Media

• Does the dam have a conduit spillway?

  Yes

  No

• Is the trash rack and anti-siphon device in good condition?

  Yes

  No

  N/A

• Is riser/inlet in good condition?

  Yes

  No

  N/A

• Does the conduit appear structurally sound including water tight joints?

  Yes

  No

  Unknown

• Are there signs of flow beneath or around the conduit?

  No

  Yes

  N/A

• Does the dam have an open chute spillway?

  Yes

  No

• Do the joints appear to be watertight?

  Yes

  No

  Unknown

• Does the chute have a drainage collection system?

  Yes

  No

  Unknown

• Are the outlet drains visible and clear of obstruction?

  Yes

  No

  Unknown

• Describe the amount of flow from the each outlet.

• Are there signs of flow beneath or around the spillway outside of designated drains?

  No

  Yes

  N/A

• Does it appear that erosion of material is occurring?

  No

  Yes

  N/A

• Is the concrete in a generally good and sound condition?

  Yes

  No

  N/A

• Is there erosion around the spillway outlet?

  No

  Yes

  N/A

• Are there trees and brush around the outlet?

  No

  Yes

  N/A

• Outlet Photos

  Media

• Is there a low level drain?

  Yes

  No

  Unknown

• Description:

• Does the gate appear watertight?

  Yes

  No

  Unknown

• Has the gate been exercised in the last year?

  Yes

  No

  Unknown

• Are the gate structural elements in good condition?

  Yes

  No

  Unknown

• Photos

  Media

• The dam has an auxiliary spillway.

  Yes

  No

• Description:

• Is the spillway free of obstructions?

  Yes

  No

  N/A

• Is there an adequate vegetative cover free of trees and brush?

  Yes

  No

  N/A

• Is the spillway free from erosion?

  Yes

  No

  N/A

• Auxiliary Spillway Photos

  Media

• Inspection notes for auxiliary spillway.

Perform the following ongoing maintenance:

• Exercise and perform required maintenance on gate.

  Perform on an ongoing basis.

  Needs immediate attention.

  Not required.

• Mow or burn the vegetation on the dam.

  Perform on an ongoing basis.

  Needs immediate attention.

  Not required.

• Clear vegetation from riprap areas.

  Perform on an ongoing basis.

  Needs immediate attention.

  Not required.

• Remove debris from spillway inlet.

  Perform on an ongoing basis.

  Needs immediate attention.

  Not required.

• Other (see notes):

• Notes

Monitor the following items that were detailed in previous sections of the report. Report any significant changes to the DNR.

• Seepage.

  Nothing noted at this time.

  Monitor and report changes to DNR.

• Minor erosion.

  Nothing noted at this time.

  Monitor and report changes to DNR.

• Minor embankment depressions or slides.

  Nothing noted at this time.

  Monitor and report changes to DNR.

• Other (see notes):

• Notes

The following items need to be properly repaired/rectified:

• Clear trees and brush from embankment and spillway areas.

  Perform on an ongoing basis.

  Needs immediate attention.

  Not required.

• Backfill rodent burrows and initiate rodent control program.

  Perform on an ongoing basis.

  Needs immediate attention.

  Not required.

• Repair and stabilize eroded areas.

  Perform on an ongoing basis.

  Needs immediate attention.

  Not required.

• Other (see notes):

• Notes

Employ an engineer/contractor experienced in design and construction of dams to:

• Perform a geotechnical evaluation to determine cause of slides and/or depressions.

  Immediately

  In the next 1-2 years.

  In the next 5 years.

  Not required.

• Evaluate and repair spillway structures.

  Immediately

  In the next 1-2 years.

  In the next 5 years.

  Not required.

• Develop plans and specifications for proper repair of the dam.

  Immediately

  In the next 1-2 years.

  In the next 5 years.

  Not required.

• Other (see notes):

• Notes

• SATISFACTORY
  No existing or potential dam safety deficiencies recognized. Safe performance is expected under all anticipated loading conditions, including such events as infrequent hydrologic and/or seismic events.
  
  FAIR
  No existing dam safety deficiencies are recognized for normal loading conditions. Infrequent hydrologic and/or seismic events would probably result in a dam safety deficiency.
  
  POOR
  A potential dam safety deficiency is clearly recognized for normal loading conditions. Immediate actions to resolve the deficiency are recommended; reservoir restrictions may be necessary until problem resolution.
  
  UNSATISFACTORY
  A dam safety deficiency exists for normal conditions. Immediate remedial action is required for problem resolution.
  

• Overall Rating of Dam Condition

  Satisfactory

  Fair

  Poor

  Unsatisfactory

• General Notes