Rain Event Adds Complexity to Management Plan
This is the first year that the DLWID has defined a method to comply with the requirements of their water impoundment permit and recent rain events have added a new level of complexity. This month’s DLWID Manager report provides a description of what to expect.
Except from DLWID Manager Report (10-07-2010)
We have had significant rains this month and as a result managing the lake level has increased in complexity. This is the first year that we have had to account for the evaporation, and thus our methodology is a bit experimental. Obviously we are widely impacted by large rain events such as we had in mid September. In the five days starting on the 15th, we had nearly 4” or rain, with a full 1.7”
recorded the first day. In response the Lake Contractor pulled 2 north boards on 9-17-10 and pulled 4 boards north to south on 9-19-10. Overtime this appears to have compensated for the heavy rains as the most recent value sits very near the theoretic value.
As we approach the end of the month we are finishing the period where inflow must equal the outflow and impoundment can again occur. However it has generally been the practice of the District to remove the dam in mid October, so there are only a few weeks left in which the lake will be artificially controlled. This is done to protect the dam structure from impact from waves and storm debris in the winter months. The removal of the full dam then is forth coming, and will be done by the Lake Contractor in the upcoming weeks.
Lake level in summer quickly turns to readiness for emergency dredging in the winter months. Currently we have most of the permits in hand, the DSL removal fill being the most important. We though also annually have to get a motor vehicle access permit for the beach for the excavator. In past years we have been able to develop a pool of contractors all whom were listed on this OPRD permit. As it has been a few years since we opened up that pool of contractors, it is my intent over the next month to solicit bid prices from area contractors and incorporate them into this pool of available excavators. We will then draw upon this pool based on the criteria of cost and availability as the need may arise for emergency dredging.