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<br /> <br /> <br /> <br />2 <br />Dam Safety Inspections… <br />A Closer Look <br />Introduction <br />Safety inspections are an important and necessary <br />responsibility of dam owners. The goal of a safety <br />inspection is to identify potential dam safety <br />deficiencies before they become dam safety incidents. <br />If not corrected, these deficiencies can turn into <br />serious, costly repairs or even dam failures. Dam <br />inspections are also a great opportunity to gather the <br />owners, engineers, experts, regulators and all <br />stakeholders involved with a dam in order to educate, <br />communicate, to delegate responsibilities, to discuss <br />possible failure modes, to plan for emergencies, and to <br />establish long term relationships concerning the dam. <br />This article is intended to be a high level overview of <br />the safety inspection process for small low-hazard <br />dams from planning to implementation. For additional <br />details regarding dam safety inspections, the reader is <br />encouraged to visit the Association of State Dam Safety <br />Officials (ASDSO) website and view the webinar titled, <br />Introduction to Inspecting Dam for Owners and <br />Operators. <br />Why are Inspections Important? <br />During an inspection of an emergency spillway, an <br />inspector identified open, unsealed joints between <br />concrete spillway slabs (Photo 1). <br />Photo 1: Concrete spillway from the inspection report. Photo <br />inset shows an open joint. <br />The openings were as wide as 1 inch and had <br />vegetation growing in them. A recommendation was <br />made in the inspection report to repair the joints, but <br />the dam owner neglected to implement the repair. <br />Four years later the spillway operated and the water <br />flowed into the open, unsealed joints causing uplift <br />pressures to develop beneath the slab that ultimately <br />led to the failure of the spillway slabs (Photo 2). It cost <br />the owner more than $1.25 million to reconstruct the <br />spillway. The spillway failure may have been averted if <br />the owner had implemented the repairs recommended <br />in the inspection report. The cost to implement the <br />inspector’s recommendation was estimated to be <br />approximately $500. <br />Photo 2: Failed concrete spillway following operation during a <br />storm event. <br />Types of Inspections <br />Typically dam safety organizations and dam owners <br />will conduct a variety of inspections including formal, <br />intermediate, routine, and emergency inspections. <br />Regulatory requirements, hazard classification, dam <br />condition, and special events dictate the scope and <br />frequency of dam inspections. A qualified engineer is <br />required for formal, intermediate, and emergency <br />inspections. Due to safety concerns, some inspection <br />activities may need to be performed as a team or with <br />the aid of specialized equipment. For example, <br />inspections of the conduit may require confined space <br />entry protocols or a remote operated vehicle (ROV). A <br />detailed discussion about conduit inspections was <br />presented in a previous article titled, You Con-du-it; <br />How to Fix a Leaky Pipe. <br />Who can be an inspector? <br />People who have: <br /> Good knowledge of the <br />design, operation, <br />maintenance, and potential <br />failure modes of the dam. <br /> The physical capability to