Drainage
Forty years of experience in building drainage system models, evaluating existing systems for condition and capacity, predicting performance of systems for the 2,5,10,25 and 100 years rain event, and designing new systems has provided vast knowledge valuable to our clients.
- Modeling drainage systems utilizing the latest stormwater modeling software is probably the most valuable service provided to our clients. It is like predicting the future from the comfort of their office. Knowing the strengths and weaknesses of the system helps develop a long-term capital Improvement Plan (CIP) to resolve short term problems and plan for the long term. The model can predict the compliance with state water quality standards and predict flooding levels in small neighborhood areas or entire drainage basins.
- New or replacement system design includes incorporation of retention detention ponds to lower peak flows, or if room is limited underground systems to meet water capacity and quality needs. The drainage routing and size determination is very critical when retrofitting an area with new system components to resolve flooding. Other infrastructure and utility conflicts are a major concern.
- Failing infrastructure has become a major concern for many state and local governments. For many years drainage systems were installed using uncoated metal pipe. These pipes now have been in the ground for 20 to 30 years, sometimes longer, and are well past their expected life. Corrosion has all but eliminated the metal in the pipe leaving major weaknesses and sometimes large voids in the system. The resultant sinkholes are dangerous, sometimes swallowing up entire sections of the roadway. Identifying what could be a massive number of installations, prioritizing the replacement and development of a Capital Improvement Program for systematic replacement of the components is the solution to this mounting problem. In our 40 years, we have developed evaluation methods and tools to know whether we have to replace or if we can apply a temporary patch then have a more orderly approach to the replacement. Avoiding emergency replacements is our goal.
Case Studies:
Problem:
In most Cities there are areas that develop over time in many phases and areas of flooding are created. One such development is Carrington Woods in the City of Milledgeville.
Solution:
The City of Milledgeville contacted Simonton Engineering to evaluate the area and recommend improvements to resolve the flooding. Our evaluation began with field investigation to identify the existing infrastructure and create a drainage model that would predict the flooding impacts on the existing residents. During this phase of the project we identified drainage pipes under houses and unusual extensions where the downstream pipes actually got smaller. Once the field work was complete and the model built areas of flooding were confirmed. Simonton Engineering then altered the drainage model of the neighborhood incorporating and evaluating many different alternatives to include strategically placed detention/retention ponds and larger pipes with some system rerouting. Our recommendation to install larger pipes rather than build detention facilities was based on capital expense plus long term maintenance.