Corps reviews Puget Island dikes

The brush cutting visible on some slopes of Puget Island dikes is intended to meet US Corps of Engineer standards for vegetation on dike slopes.

The Wahkiakum Consolidated Diking Improvement District Number 1 has cut brush on Puget Island, and will continue around the Little Island, when the brush-cutting machine it bought from Wahkiakum County has been repaired, Gordon Oman, district chairman said.

Oman said the district will begin to remove trees next. Corps standards state slopes should be clear of brush and trees over 2 inches in diameter in the “vegetation free zone, which extends outward to the riverward right-of-way and landward 15-feet from the levee toe” so that the slopes of the dikes can be inspected for damage.

Oman said the district would contact landowners about trees needing to be removed. If there were questions, the district will request a decision from the Corps. He said the district would pay for the tree removal.

In April, 2010, the Corps made its first periodic inspection in which consultants walked the dikes and inventoried crossing and encroachments on the dike right of way.

The district received a rating of minimally acceptable, according to a report provided the Puget Island Dike District in November. The Corps rates systems as acceptable and minimally acceptable, which allow federal funding, and unacceptable, which requires immediate corrective action. The reports contained some items which must be corrected. If damages occurred as a result of the deficiencies noted, they would not be compensated with federal assistance.

The executive summary is available at the Corps’ Portland District website http://www.nwp.usace.army.mil/water/levees.asp, and concludes that while the deficiencies are serious, the levees should operate properly in a flood.

Inspectors walked the19 miles of earthen levee and inspected three drainage structures and six pump stations that make up the flood-protection systems of Puget Island and Little Island built in 1939 and 1940.

In addition to unwanted vegetation on levee slopes, the report described the encroachments into the levee right of way that are primarily fences, underground and above ground utilities.

Most are acceptable, some 129 were minimally acceptable, and four were rated unacceptable—items that must be corrected as they would seriously impair the dike’s function during a flood event. These included a fence that allowed cattle to graze on the landward slope. Standards require fences located along the levee toe to have a 10-foot wide access way between the levee and the fence.

The inspectors located a waterline through the levee that had ruptured and caused a sink hole on the riverward slope near the top of the levee. The consensus of the cause of the1948 breach of Puget Island dike was a result of a water line breaking during high water, according to the report.

Pump stations were unacceptable for a lack of Megger testing on motors and critical power cables. Some sluice and slide gates were damaged or inoperable. The district, which has no employees or office or files, per the report, had inadequate operation manuals, maintenance equipment manuals and inspection records. The district operates with contracted staff.

The district is addressing items in the report.

No existing utilities need to be removed, Oman said. The district stopped allowing new connections through the dike in 2009. At present the Wahkiakum PUD is replacing existing water pipe because the material, polybutylene, breaks down, PUD Manager Dave Tramblie said.

In the aftermath of Hurricane Katrina, the Corps became more stringent about enforcing rules, District Commissioner Philip Vik said.

The Corps used stimulus money (The American Recovery and Reinvestment Act of 2009) for the periodic inspections and plans to return in five years.

All of the nine inspections of diking districts in the Corps’ Portland district were rated minimally acceptable.

Judi Strayer, manager for Cowlitz Consolidated Diking Improvement District 1, which maintains 16 miles of levees along the Columbia and Cowlitz rivers with seven fulltime employees, said the report they received was not completely accurate, and staff is providing context and history.

Both Oman and Vik used the same words to describe landowners’ reaction to the rules. “We’re going to be real popular.”