The CB at Ross also collects stormwater from around the corner E Main St on the North side. I don’t believe there is an inlet on E Main on the north side of the street for a block or more. There may also be water collecting from both the City parking lots that tie into that line to the East on Ross.
See my best drawing of flows
Jennifer Cline, P.E.
City of Molalla
Public Works Director
O: 503.759.0218
F: 503.829.3676
"From: Jim Pex [mailto:Jim.Pex@msa-ep.com]
Sent: Tuesday, June 09, 2015 3:45 PM
To: Jennifer Cline
Cc: Chris Link; Randall Stark; Hash, Kenneth F.; Adam Shultz; Dennis Welle
Subject: RE: Stormwater Ponding Areas
Looking at the overall facilities and the inspection reports I have a pretty clear view of why there is so much ponding.
From 3rd to Main there is only a single inlet at the cross-street intersections for 3rd & 2nd on the south side. The roadway is crowned on the cross streets and in Molalla. So any water for nearly 3 blocks that gets to the northern side of the roadway doesn’t have a place to go for a long way. Both of these Xstreet CB’s also had debris in them from the video to add to the backflow.
Second, in this region, the street slopes for Molalla are inconsistent at best having a lot of small grade breaks. Not unusual for an older road and with overlays, but it creates flat areas where water won’t drain well.
Third, the entire west side of the road doesn’t have a single inlet from the intersection of 5th all the way to Main (1350 feet). With a crowned roadway, it’s not a surprise at all you have issues in this area.
As of Ross, there are only CB’s on the south side of the street. So once again, water sloping to the north will have immediate ponding issues as there isn’t any CB’s until you get to Robbins. Not a surprise, but should be solved with the new layout.
The fix is also relatively easy. A constant slope to the road grade will allow for continuous flow. Adding catch basins to the northern part of intersections and to the west side of the road will give it a place to go. I’ll upsize a little piping to have some capacity, but that should solve it. Good height on curbs will keep water from being troublesome outside the gutter line.
Anyhow, thought I would update you on these two spots.
Jim Pex, P.E. | Civil Engineer
T: 541.741.2975 Cell: 541-972-0851| Jim.Pex@msa-ep.com
175 West B Street, Bldg. K-2 | Springfield, Oregon 97477-4575 | www.msa-ep.com
Murray, Smith & Associates, Inc. | Your Public Works Partner
Notice: This e-mail and any attached files are the private confidential property of the sender, and the materials are privileged communications intended solely for the receipt, use, benefit and information of the intended recipient indicated above. If you are not the intended recipient, you are hereby notified that any review, disclosure, copying, distribution, or taking of any other action in reliance on the contents of this transmission is strictly prohibited, and may result in legal liability on your part. If you have received this e-mail in error, please notify us immediately at the above address.
P Please consider the environment before printing this e-mail.
From: Jennifer Cline [mailto:jcline@cityofmolalla.com]
Sent: Tuesday, June 09, 2015 1:49 PM
To: Jim Pex
Cc: Chris Link; Randall Stark; Hash, Kenneth F.; Adam Shultz; Dennis Welle
Subject: RE: Stormwater Ponding Areas
Hi Jim,
We have ponding during heavy rain events on N. Molalla between Main & 3rd St. and on S. Molalla at the SE corner of Ross St.
I will need to verify with the crew if there are any additional locations they have seen ponding. I believe its due to the fact our storm inlets and pipes cannot handle the capacity. This may be due to the under sized pipe sections where repairs have been made with PVC.
Jennifer Cline, P.E.
City of Molalla
Public Works Director
O: 503.759.0218
F: 503.829.3676
From: Jim Pex [mailto:Jim.Pex@msa-ep.com]
Sent: Tuesday, June 09, 2015 1:37 PM
To: Jennifer Cline
Cc: Chris Link; Randall Stark; Hash, Kenneth F.
Subject: Stormwater Ponding Areas
Hi Jennifer, I’m going over my notes with regards to the stormwater discussions. I recall discussion about ponding in certain areas but we didn’t identify them. In more specifics, do have areas of concern (block to block) or even a specific manhole/address that we can look at? Since the video noted blockages in several locations, I will make sure to compare the areas of concern with those problems and might upsize pipe if need be for holding capacity.
Thanks in advance.
Jim Pex, P.E. | Civil Engineer
T: 541.741.2975 Cell: 541-972-0851| Jim.Pex@msa-ep.com
175 West B Street, Bldg. K-2 | Springfield, Oregon 97477-4575 | www.msa-ep.com
Murray, Smith & Associates, Inc. | Your Public Works Partner
Notice: This e-mail and any attached files are the private confidential property of the sender, and the materials are privileged communications intended solely for the receipt, use, benefit and information of the intended recipient indicated above. If you are not the intended recipient, you are hereby notified that any review, disclosure, copying, distribution, or taking of any other action in reliance on the contents of this transmission is strictly prohibited, and may result in legal liability on your part. If you have received this e-mail in error, please notify us immediately at the above address.
P Please consider the environment before printing this e-mail.