Municipal Separate Storm Sewer System (MS4) Permit Compliance
Client: Post Falls Highway District, Lakes Highway District (2009-2013)
Municipal Separate Storm Sewer System (MS4) Permit Compliance (2009-2013)
Clients: Post Falls Highway District, Lakes Highway District
Eric Olson of HMH Engineering assisted the Post Falls Highway District, and later Lakes Highway District, with ongoing MS4 permit compliance. Eric took a lead role in this endeavor, preparing the District’s Storm Water Management Program documents and Annual Reports, leading staff training sessions, conducting dry weather screening, and attending coordination meetings with other area MS4 permittees and the EPA. Just prior to joining HMH, Eric was instrumental in bringing East Side Highway District into the fold under a joint MS4 permit with the other highway districts.
This Project Included:
⦁ Storm Water Management Program documents
⦁ Mapping MS4’s and outfalls for Post Falls and Lakes Highway Districts
⦁ Illicit Discharge Detection Program document, monitoring, and reporting
⦁ Coordination with other MS4 permittees in the CDA Urbanized Area
⦁ Preparation of Annual Reports
⦁ Participation in the City of Coeur d’Alene’s Environmental Open Houses
⦁ Dry Weather Screening
⦁ Creation and distribution of educational literature to the public
⦁ Staff training sessions with Post Falls and Lakes Highway District maintenance staff
⦁ Phone calls, meetings, and inspections with the Environmental Protection Agency
Spokane Street Drainage Improvements (2012)
Client: Post Falls Highway District
Eric Olson of HMH Engineering worked with the Post Falls Highway District and the City of Post Falls on a drainage improvement project located on Spokane Street just south of the Spokane River. The main problem was that a large subcatchment drained to a low area by the river which tended to generate a lot of debris (mostly pine needles) that would block the inlets located at the low area resulting in ponding between the curb lines. A secondary problem was that when the water did make it to the inlet and out of the nearby outfall, it eroded the bank adjacent to the Spokane River.
The solution developed by Mr. Olson was twofold: (1) decrease upstream flow by installing curb cuts and a drainage swale, and (2) install larger catch basins and divert the outlet to a new swale in an existing lawn area within Q’emiln Park. As a result of the project an outfall was eliminated from the District’s MS4 map.
Hauser Lake Outfall Hydraulic Analysis (2012)
Client: Post Falls Highway District
As part of a project to replace a deteriorated culvert on Cliffhouse Road, Eric Olson performed a hydraulic analysis to ensure that the replacement culvert would not adversely affect the performance of the culvert. The culvert is situated in the Hauser Lake outlet channel and acts to restrict lake outflow during flood conditions. The culvert analysis was performed using surveyed cross sections and the Army Corps’ HEC-RAS software.
Rice Avenue Drainage Improvements (2011)
Client: Post Falls Highway District
Excessive flows in the ditch line of Rice Avenue near Hauser was causing erosion and culvert blowouts. Eric Olson designed a diversion channel, swale and drywell system that corrected the problems.
