autumnwood park pond retrofit project
DESCRIPTION
Autumnwood Park Pond Retrofit ProjectTRANSCRIPT
Autumnwood Park Pond Retrofit Project
Hunter Mill District, Tax Map No. 25-1 Project No. SD-000031-129
Project Details
Description: The purpose of this project is the retrofit of an existing Stormwater Management Facility, referred herein as Autumnwood Regional Pond 330DP. The pond is located at 11950 Walnut Branch Road in Reston, VA, along Walnut Branch Road just east of Fairfax County Parkway, just west of trails edge lane and south of Lake Newport Road. The primary goals of this project were to provide water quality and to increase the storage of the pond.
Project Overview: • Excavating and constructing one forebay, wetlands, seven cascade steps and three micro-pools.
• Installing seven 16” coir logs in the adjacent woodland space in order to prevent eroded sediment large debris from blocking flow
exiting the facility.
• Water quality benefits obtained are 7.7 lbs./year of phosphorus, 63.4 lbs./year of nitrogen, and 2,720 lbs./year of total suspended
solids from the runoff leading to Sugarland Run.
• The disturbed area was restored with riparian seed mixes and native trees.
• DPWES Project Team: * Project Manager: Fred Wilkins * Construction Manager: Yousef Rayyan * Survey Analyst: Gregory Harper * Project Inspector: Keith Ferrell
Autumnwood Park Pond Retrofit Project
Hunter Mill District, Tax Map No. 11-3
PROJECT SITE
LIMITS OF DISTURBANCE
An Existing Riser
NORTH
PRE-EXISTING CONDITIONS WETLAND CELL AREA
THE PRE-EXISTING POND BEGINS WITH A LARGE OPEN GRASS FIELD THAT GRADUALLY SLOPES TOWARD THE RISER STRUCTURE
THE RISER STRUCTURE
CONSTRUCTED WETLAND CELL WITH FOREBAY
CONSTRUCTED FOREBAY
CONSTRUCTED WETLANDS
PLACED REINFORCED BEDDING MATERIAL AT INFLOW LOCATION
PRE-EXISTING RISER
THREE CONSTRUCTED MICRO-POOLS
PRE-EXISTING 36” CPP PIPE
PRE-EXISTING CONDITIONS MICROPOOL AREA
LOGS AND OTHER LARGE DEBRIS FREQUENTLY CREATED
BLOCKAGES AND PREVENTED FLOW FROM PRE-EXITING THE
POND.
HIGH AMOUNTS OF SEDIMENT OFTEN CLOGGED THE TRASH RACK CREATING DRAINAGE
PROBLEMS.
PRE-EXISTING CONDITIONS MICROPOOL AREA
DAM EMBANKMENT PRE-EXISTING RISER BMP ORIFICE ERODING CHANNEL
CONSTRUCTED MICROPOOL AREA
FLOW FROM THE WETLAND CELL IS DIRECTED INTO MICRO-POOLS THROUGH A CASCADE
THREE NEWLY CONSTRUCTED MICRO-POOLS
PLACED REINFORCED BEDDING MATERIAL TO TREAT ERODED AREAS
PRE-EXISTING BMP ORIFACE
For additional Information, please call Irene Haske, Public Information Officer
703-324-5821, TTY 711 [email protected]
www.fairfaxcounty.gov/dpwes