Tom Rozman: Avoiding Catastrophe

Avoiding Catastrophe

Article by: Tom Rozman

A state park experienced an extended period of unprecedented heavy rain.  The park was one of the parks in the State Parks Division’s Piedmont Region and excessive rain in the water table put immense stress on the park’s dammed lake, a vital aspect of the park as a destination for the public.  Adding to the concern was that the impoundment basin’s management for funding reasons had deferred restoring the holding capacity of the basin by draining the lake and removing sedimentation and debris that had been filling the basin–in some areas of the shoreline eutrophication was becoming apparent.  The park and new region manager had been reviewing the issue before the storm hit to develop a project approach.

Both the park and region manager were firm believers in the principle of synergy through well established inter-organizational relationships.  State budgets could be very parsimonious and not infrequently funding for key initiatives could be short or not at all. To stay ahead of many situations, working systems that could do more with less were critical to operations.  The two managers, in this line of thinking, worked every angle to develop working inter-organizational relationships.

Through these close inter agency associations and relationships with other state and local government organizations such as the Transportation Department, the Department of Fish and Game, Department of General Services, State Police, local police and sheriff’s offices and other organizations, many mutually beneficial relationships were possible and had accordingly been developed.  The region manager particularly believed in such arrangements from many lessons he had learned over a long previous career in the Army where strong inter-organization relationships were critical to mission success.  He found the civilian situation to be no different.  The situation about to develop would underscore the correctness of this position.

The storm produced water table drainage had developed a flow well beyond the carrying capacity of the park impoundment’s basin.  As a result, the basin’s overflow capacity was significantly exceeded and the earth dam was being greatly stressed.  It’s overflow system was showing signs of failure.

Though the main dam held, the in effect dam of the lower overflow basin below the spillway, which was a compacted earth structure that spanned the small valley that the original stream course flowed through, came close to failing.

Half way along the earth structure was a concrete bridge, actually a one-piece concrete structure that under certain conditions could act as a venturi, constricting the flow of water and sending a high-pressure water jet of tremendous velocity and force in the direction of flow.  This jet of water had developed as the excessive rainwater drained from the water table above the impoundment.

Fortunately, the gorge-like original streambed dropped some 40 or more feet and the water would shoot into the air dropping into the bed below as force was lost.  But the effect was spectacular and caused park staff in the area to become greatly alarmed when such development occurred.

The storm water had filled the overflow basin.  Building pressure in the overflowing basin was causing the water roaring through the “venturi” to shoot a huge jet of water at great velocity a good 200+ feet over the gorge. At some point the building water began to overflow the earth structure constituting the overflow basin’s dam.  This included the road on top of the structure.

This catch basin dam also served as the roadbed for the entry road to the state park.  It carried the electric, water and sewage lines.  The force of the water began to eat away the earth on either side of the concrete bridge threatening to erode the packed earth anchoring the structure and firing it into the gorge which if this happened, with the then force of the water, would fundamentally weaken the earth structure probably causing its failure.  Had it failed and destroyed the road into the park, the park would have been temporarily isolated.  Its water, sewage and power would have been cut as well.

Fortunately, the storm finally abated before a failure occurred.  However, the damage caused by this point was extensive.  The concrete bridge and earth structure around it and the roadway needed to be evaluated and an immediate project initiated to restore both.  Unfortunately, no funds were available for such an unfunded or projected project.  Damage to this extent had not been predicted under any assessments that had been made for repair or upgrade projects in any maintenance reserve or capital project planning.

The region manger immediately traveled from his office in the state capital and met with the park manager coordinating an initial joint meeting with the district state transportation department engineer.  The meeting at the site estimated a $100,000+ project in 1994 dollars to restore the structure.  After some discussion, the park managers and the transportation engineer developed a plan to pull from existing resources and divert some existing funding sufficient to initiate and complete the project.  The team decision was made to proceed.

An important factor in the successful development of this project was earlier outreach to the Transportation Department staff in the area. Both the region and park manager had previously made the effort to establish rapport with State Transportation Department leaders in their respective areas.  The district engineer knew the park and park region managers and a climate of mutual respect existed.  The three professionals were able to get quickly to what needed to be done and how to do it thus making an informed decision to proceed.

The project initiated and the roadway was restored.  The restoration allowed the park to operate safely, receive its electricity and continue its sewage service.  As well, the ability of the earth structure to act in its overflow basin capacity as a dam was also restored.

The achievement of this successful result underscores the importance of prompt involved leadership in an unprogrammed or unplanned significant incident to quickly assess the issue and engage resources to correct the situation and make the decision to do so.  To a great degree the success experienced in this case was the product of previous inter-agency relationships that had been developed and nurtured over time.  The key individuals in the problem solution group had knowledge of each other and mutual respect in each other’s capabilities. In many ways it had the characteristics of an incident command approach.

Consequently, a competent and able ad hoc project team formed and was able to move forward on corrective action rapidly, restoring a situation that threatened to put the park out of business with a major access problem.  It is fortunate however that a period of over two weeks of precipitation, some of it torrential, came to an end and allowed the ground to dry and the project to proceed.  The park leadership had much food for thought from some of the lessons learned. This reflection led to further initiatives  to take to improve their systems and arrangements for possible similar developments in the future.