HomeMy WebLinkAboutRETREAT AT 1200 PLUM ST. - PDP - 34-08 - CORRESPONDENCE - (12)(12/9/2008 Anne Aspen - Fwd: Retreat at "'00 Plum Page 1
From: Roger Buffington
To: Anne Aspen
Date: 12/8/2008 4:31 PM
Subject: Fwd: Retreat at 1200 Plum
Anne,
This is the email sent to Nick Haws at Northern Engr'g regarding stormwater items.
Roger
>>> Wes Lamarque 11/21/2008 15:22 >>>
Nick,
Stormwater Staff had a meeting today with upper management to discuss the proposed underground
pumped detention and the water quality treatment shown in the first submittal. We wanted to notify you of
the essential outcomes to this meeting.
If underground detention were to be accepted, the pond must have a gravity outfall. It may be possible to
tie into the Shields St. storm sewer at a lower elevation somewhere in the system. The City feels having
underground detention with pumps is not a system that will be sustainable in the long run. At any rate,
even surface pumped detention must provide two times the required volume.
The development must also have no adverse impact to the drainage system. Two known areas of
concern are Plum Street and Aster along with Shields and Elizabeth. One of the comments at the
Conceptual Review meeting included the statement that "The design engineer will need to further define
the flooding using more detailed topography". That was not included in the submittal. Therefore more
survey data is needed along Plum Street and modeling to better determine the water surface elevations in
this area. In addition more survey information should be obtained on the storm sewer outfall system to
determine if a lower storm sewer could be installed in Plum.
Water quality mitigation must be provided per City requirements. There are some new innovative ways to
treat run-off from building roofs that can be incorporated into the design. The City can provide information
related to these water quality measures. The water quality measures currently proposed in the right-of-
way are very controversial to the Engineering Department and the Stormceptor does not meet our full
water quality treatment requirements. They only remove large particles and not most suspended
contaminants.
If you have any questions, please don't hesitate to call
Wes