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WEB-BASED HANDBOOK (Legacy Edition). CLICK HERE to submit comments.
Because of staff changes and Randolph Langenbach's retirement from FEMA, these handbooks were never published on the FEMA website.  These are the only copies available.


 

Chapter 5: UTILITIES 

B. Soil Settlement

Introduction

Problem:

Consolidation and settlement of soils that damage a utility facility during a flood event.

Mitigation Objective:

Protect the utility from soil settlement, including slides, from future damage

B.1 Line Damaged Pipes

Provide a lining inside damaged storm and sanitary sewer lines to prevent infiltration and/or exfiltration and associated erosion and settlement. Lining will also prevent increased flows due to infiltration of excessive groundwater that could overwhelm treatment plants or other facilities during periods of wet weather. Several lining techniques are available. The most common techniques are slip lining and inversion lining.

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Effectiveness:

  • Very effective
  • Will prevent infiltration/exfiltration of floodwaters.

Limitations:

  • Lining may not be useful if system components are too far out of alignment.
  • May not be feasible for small diameter pipes.

Considerations:

B.2 Bury the Utility

Place above ground utilities, such as transmission and distribution lines for electricity and communication lines, underground to avoid damage from floodwaters, debris, and from soil settlement.

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Effectiveness:

  • Very effective

Limitations:

  • Maintenance access may be restricted. 
  • Buried utility lines could be vulnerable to earthquakes, slides, or other earth movement events.

Considerations:

 

NOTE:  None of the mitigation measures in these Handbooks should be considered ‘pre-approved’ or otherwise automatically eligible for FEMA funding. Only FEMA staff can determine eligibility, once they have determined that an applicant is eligible and they have reviewed a project proposal.

FEMA HAZARD MITIGATION HANDBOOKS                                                                        Updated: June 13, 2002