FLOOD06961 - Laserfiche WebLink

Home Browse Search

MEETING MINUTES development and inadvertent detention upstream of S Oak Street. David noted that the primary flow path of Massey Draw is north of W, Rockland Drive, not south. He also noted that the master plan overlot grading showing the area west of W. Rockland Drive does not match the hydrology model developed by JR Engineering. David showed a schematic of the HEC-RAS model developed by OA to simulate the flow splits that occurred, Ben Urbonas asked whether the splits had been balanced by matching energy grade lines, David verified that they had and noted that iterations between the UDSWMM and HEC-RAS models were made to refine both models. I '. I I I I I I I I I I I I I I I I I 0\ Massey Draw and SJCD Update Project Meeting Minutes August 27.2004 Page 2 of 3 OLSSON ASSOCIATES EN G IN E ERS' PtANNE RS' SCl E NTlSTS' SU RV EYORS 143 Union Blvd. Suite 700 Lakewood, CO 80228 720-962~6072 Massey Draw and SJCD (South) Update OA Project No. 02-2003-1321 August27,2004 2, Observations during the June 27, 2004 flood event included the following: . Water was at least up to the fence and possibly in the back yards of some of the homes south of W. Rockland Drive. . The golf course boardwalk was not overtopped, . Some fences were broken out along both S, Oak Street and W, Rockland Drive, The fences along W, Rockland Drive had wire in addition to split rails, but those along S. Oak Street did not. . Water flowed around both sides of the house south of Rockland Drive and east of the detention pond #2 outlet. 3. Bill DeGroot asked if the golf course was subject to U.S. Army Corps of Engineers (USACE) 404 requirements, Jason Murphy said that 404 issues had been fully resolved and approved for the northern portion of the golf course. He also said that the golf course recently removed some wetlands east of the boardwalk and developed some west of S, Oak Street. The recent activity was subject to USACE requirements. Jason noted that when it rains. water discharges from Pond #1, but there is no actual base flow. If an alternative is selected that diverts water to the south of W. Rockland Drive, a base flow to the new wetlands will have to be maintained or the impacts to the wetlands will have to be mitigated at another location. Attendees: Kathy Christensen - Meadow Ranch Master / KC Association Bob Deeds - City of Littleton Bill DeGroot - Urban Drainage and Flood Control District (UDFCD) Paul Duncan - Professional Investigative Engineers (P,I.E,) Paula Lundquist - Jefferson County Jason Murphy - Deer Creek Golf Club Chris Plant - Meadow Ranch board member / resident Rick Schultz - Deer Creek Golf Club Harry Strasser - PBS&J Ben Urbonas - Urban Drainage and Flood Control District Bruce Buttner - Olsson Associates (OA) David Krickbaum - Olsson Associates Deb Ohlinger - Olsson Associates Minutes Additions/Corrections: None . Comparison of Meadow Ranch 100-year detention pond volumes and discharges (detention basin design vs. parallel hydrology model) Comparison of parallel and baseline model discharges Comparison of 10-year and 100-year hydrographs at Kipling St. from baseline and parallel models Flow splits upstream of West Rockland Drive Meadow Ranch alternatives matrix Meadow Ranch alternatives figures (7) 4. The golf course irrigation water supply is diverted from Massey Draw to a pond southwest of detention pond #1 (the driving range). Water is piped underground from this pond to detention pond #3 (north ofW, Remington Avenue), Jason mentioned that the golf course has a junior water right from Massey Draw but was not sure of the maximum adjudicated flow rate. The pipe that receives the flow is small, perhaps 18 inches in diameter. Jason and Rick Schultz thought that it might be possible to add an irrigation pond and pump house near hole 15 if the existing irrigation system requires modification due to possible floodplain improvements. Items Distributed: . . . . 5. Jason noted that the Massey Draw channel is eroding through the golf course. He asked who is responsible for the channel maintenance. Ben said that it is the property owner's responsibility to maintain the channel. . Discussion Items: 1, After introductions and an explanation of the project purpose and background. David Krickbaum discussed the development of the parallel hydrology model and comparisons to the baseline hydrology model. The parallel hydrology model incorporates the three detention basins constructed with the Meadow Ranch 6, Kathy Christensen noted that erosion occurred on the upstream and downstream ends of the culvert under W, Rockland Drive. It was stated that repairing the erosion is the responsibility of the property owners.