Autumnwood Park Pond Retrofit Project

1. Autumnwood Park Pond
Retrofit Project
Hunter Mill District, Tax Map No. 25-1
Project No. SD-000031-129

2. 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
* Survey Analyst: Gregory Harper
* Construction Manager: Yousef Rayyan
* Project Inspector: Keith Ferrell

3. Autumnwood Park Pond
Retrofit Project
Hunter Mill District, Tax Map No. 11-3
LIMITS OF
DISTURBANCE
PROJECT
SITE
NORTH
An Existing Riser

4. PRE-EXISTING CONDITIONS
WETLAND CELL AREA
THE RISER STRUCTURE
THE PRE-EXISTING POND BEGINS
WITH A LARGE OPEN GRASS FIELD
THAT GRADUALLY SLOPES
TOWARD THE RISER STRUCTURE

5. CONSTRUCTED WETLAND CELL
WITH FOREBAY
CONSTRUCTED
FOREBAY
CONSTRUCTED WETLANDS
PRE-EXISTING RISER
THREE CONSTRUCTED
MICRO-POOLS
PRE-EXISTING 36” CPP PIPE
PLACED REINFORCED BEDDING
MATERIAL AT INFLOW LOCATION

6. 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.

7. PRE-EXISTING CONDITIONS
MICROPOOL AREA
DAM EMBANKMENT
PRE-EXISTING RISER
BMP ORIFICE
ERODING CHANNEL

8. CONSTRUCTED MICROPOOL AREA
THREE NEWLY CONSTRUCTED
MICRO-POOLS
FLOW FROM THE WETLAND CELL IS
DIRECTED INTO MICRO-POOLS THROUGH A
CASCADE
PRE-EXISTING BMP
ORIFACE
PLACED REINFORCED BEDDING MATERIAL TO
TREAT ERODED AREAS

9. For additional Information, please call
Irene Haske, Public Information Officer
703-324-5821, TTY 711
SWPDmail@fairfaxcounty.gov
www.fairfaxcounty.gov/dpwes