Periodic dam inspection is a key aspect of dam safety. Most dams regulated by state governments are required to be inspected at one- or two-year intervals, and the inspections usually follow an established format. Key elements in the inspection include the condition of the dam and its abutments and the condition of major hydraulic structures such as the principal and emergency spillways. An inspection typically includes a review of available monitoring data. Applicable state forms must be completed, and documentation with photographs is essential. D'Appolonia has performed numerous dam inspections and our dam inspection staff is trained to recognize conditions that indicate potential hazard.

Hydropower dams regulated by the Federal Energy Regulatory Commission (FERC) are required to have an inspection (Part 12 Inspection) every five years. FERC inspections require that an Independent Consultant perform the inspection and that a Facilitator be retained to lead a session referred to as Probable Failure Modes Analysis (PFMA). PFMA session participants include the owner's representatives, FERC staff, the Independent Consultant and the Facilitator. D'Appolonia staff members have served both as Independent Consultants and as Facilitors for FERC-regulated dams.

Large earth embankment dam that is part of a pump storage hydroelectric project for which D'Appolonia per-
formed a FERC Part 12D Inspection.

Some descriptions of projects describing D'Appolonia's capabilities relative to dam inspection are provided in the following:


Part 12D Inspection and Facilitation Services for Hydro Facilities

D’Appolonia provided FERC Part 12D Independent Consultant services related to inspection of the French Landing Dam on the Huron River in Van Buren Township of Wayne County, Michigan. We also provided facilitation services for a PFMA session conducted as part of the Part 12D Inspection process for the Cascade Dam located on the Thornapple River in Cascade Township, Kent County, Michigan.

FERC Part 12D Dam Safety Inspections and Remedial Studies

D'Appolonia has conducted 5-year FERC inspections and performed stability, PMF and dam breach analyses for the Hawks Nest Dam. The inspections have included evaluation of the dam, bridge and spillway gate structures, penstocks, powerhouse, and 3-mile-long by 40-foot-diameter power tunnel. The inspection scope has also included evaluation of the power tunnel intake structure and diving inspections of the tailrace and stilling pool area.

Field Inspection and Remedial Design for Lake Milton Dam

D'Appolonia performed a detailed field inspection and performed stability and other engineering evaluations of Lake Milton Dam, a 60-year-old, 50-foot-high, earth-fill and concrete gravity dam located in northwest Mahoning County, Ohio, approximately 10 miles west of Youngstown.

Safety Inspection and EAP Preparation for Seven Dams in Pennsylvania

D’Appolonia was retained by the Pennsylvania Department of Environmental Protection (PADEP) Bureau of Waterways Engineering to perform field inspections and to prepare Emergency Action Plans for seven earth embankment and concrete-gravity dams located in several Pennsylvania counties.

Lake and Channel Restoration at Deer Lakes Park

D'Appolonia performed an environmental assessment, including water quality and aquatic life studies for the Deer Lakes Park project. We were also responsible for topographic mapping, depth soundings, water quality testing, hydrological analyses and other studies related to restoration of the lakes and flow channels at the park.