Underwood & Associates wins Two National Bubba Awards

Underwood & Associates wins Two National Bubba Awards

Once again this year U&A provides the award winning national leadership for restoring water resources to good health. This is the 3rd year running that our work was chosen as THE outstanding work in both categories from the Chesapeake Stormwater Network

First Place  2017 Best Stream Restoration

North Cypress Branch Stream and Wetland Restoration

This project used an integrated watershed restoration approach, creating or enhancing 7.4 acres of non-tidal wetland through the approximately 3,000 linear feet of stream restoration in a highly urbanized watershed. The project used a variety of techniques, including the creation of headwater wetlands, floodplain reconnection, creation of seepage wetlands in low order tributaries, and natural channel design to improve water quality treatment and enhance habitat function. Water quality benefits were measured through extensive post-construction monitoring.

Diverse Plant Community at North Cypress Branch

 

Project Team:

Anne Arundel County

Clear Creeks Consulting

BayLand Consultants and Designers

Underwood and Associates

Angler Environmental

North Cypress Branch – Best Stream Restoration:

 

Anne Arundel County’s Department of Public Works completed the North Cypress Branch

Stream and Wetland Restoration in February of 2013. North Cypress Branch is a perennial

stream system with a 354 acre watershed over 50% impervious – flowing through Severna

Park, Maryland to the Magothy River. Since the conclusion of construction, the project has

continually evolved to demonstrate its potential of being theBest Stream Restoration.  The

restoration of North Cypress Branch demonstrates an integrated watershed approach, as it was

installed in conjunction with three additional BMPs that served to reduce the volume of water

flowing from upland impervious areas. The restored system has improved stream function and

hydrology, achieved through its broad floodplain and associated wetland systems, resulting in a

reduction of sediment flowing downstream and significant biological uplift. In August of 2014,

tipping rain gauges installed on site captured 6.11 inches of rain, which fell within a 12-hour

period. North Cypress Branch and the retrofitted BMPs all stood firm, and demonstrated the

stream system’s stability and ability to dissipate energy by spreading water throughout its broad

floodplain, as designed. Furthermore, Anne Arundel County funded a study by Drs. Michael

Williams and Solange Filoso with the University of Maryland’s Center for Environmental

Science. Drs. Williams’ and Filoso’s study focused primarily on hydrochemical components of

the system, which showed the system to be less flashy and to significantly reduce the amount of

nutrient and sediment pollution flowing downstream. MDE approved interim rates, per linear

foot, suggest the following nutrient reductions: TN: 225lb/yr; TP: 204lb/yr; TSS: 22.7tons/yr.

Measured reductions are included on Page 31 of the attached monitoring report.

See the report:

1483632477_CBL_Final_Report_Magothy_Project_FINAL_reduced

During Large Rain Event -Reconnected Floodplain

 

Intent of Project and Key Objectives Accomplished:

The intent of the North Cypress Branch Stream and Wetland Restoration project was to improve

the stability, nutrient processing, and ecological function of the stream system. Prior to

construction, the stream channel was eroding and conveying pollutants downstream into tidal

Cypress Creek. In 2004, Anne Arundel County DPW dredged tidal Cypress Creek to allow

continued boat access within the tributary. As part of that dredging permit, the Army Crps of

Engineers required the County to address the sediment sources in the upland areas. The County

examined the watershed to determine the best ways to mitigate the sediment issues. This study

proposed the comprehensive approach that was finally implemented in 2012. The approach

focused on the retrofit and repair of multiple upland BMPs in the stream’s watershed, coupled

with the restoration of the stream itself. A suite of smaller retrofits and repairs were performed

shortly after the permit was issued with the largest, and possibly most impactful, retrofits

beginning in 2011 with the stream’s ultimate restoration concluding in early 2013. The large

retrofits included the retrofit of a bioretention area downstream of a local Park and Ride, which

resulted in a facility that is approximately one foot deeper after construction and treats 1” storm

events. An additional retrofit was installed at a nearby dry pond located off Leelyn Drive. At

this site a step pool storm conveyance (SPSC) system was installed that increased the pond’s

treatment capacity from the 0.35 inch storm event to up to the 2.6 inch event, after periods of dry

weather. The final upland retrofit was the installation of an infiltration system in the Dunkeld

Manor neighborhoodâ’s dry pond. This retrofit improved infiltration in the facility and roughly

tripled the treatment capacity from about the 0.2 inch storm event to about 0.67 inch storms.

These upland retrofits ultimately resulted in less runoff and fewer pollutants entering the North

Branch of Cypress Creek. Finally, the stream and wetland restoration project was installed

3 immediately after the upland BMP retrofits were completed. The stream and wetland restoration

utilized a suite of techniques, including creation of headwater wetlands, transitions to

anastomosed braided channels then a single thread channel, floodplain reconnection through use

of low profile valley wide grade controls, creation of sand seepage wetlands (SPSCs) in lower

order tributaries, and natural channel design. The stream restoration ultimately resulted in the

creation/enhancement of 7.4 acres of non-tidal wetland (a net gain of 3.3 acres of wetlands)

through the approximately 3,000 linear feet of stream restoration. This comprehensive design

and utilization of diverse techniques accomplished all the goals of the project, providing a stable

stream channel that reduces sediment and nutrient pollution from moving downstream andcreating acres of diverse beneficial habitats.

Major Site, Design, or Construction Challenges:

Stream projects are inherently complicated to design, permit and build. North Branch Cypress

Creek presented its own unique obstacles and opportunities through its design process that

spanned several years. The primary challenges were posed by the large scope of the project, the

coordination of multiple design consultants, and the streams very urban watershed and flashy

hydrology. The stream restoration’s size, spanning 3,000 linear feet of stream and over nine (9)

acres of disturbance required the County to hire multiple design teams, composed of Clear Creek

Consulting and BayLand Designers and Consultants creating the plans for the main stem

restoration. Underwood and Associates was hired to design SPSC systems in ephemeral

tributaries and stormwater outfalls that entered the main channel throughout the length of the

project. The coordination of this extensive design team required County project managers to pay

especially close attention to all teams in order to ensure the designs provided by each consultant

tied together seamlessly to create functional end product. The project’s size and large urban

watershed, with over 50% being impervious surfaces, presented additional issues to the

construction contractor, Angler Environmental. Construction required the stream to be

temporarily diverted. This diversion led to the constant maintenance of clear water pipes and

channels, even during large storm events such as Superstorm Sandy, which occurred during

construction. The diversion of the stream also required the contractors to monitor adjacent

properties to ensure adverse flooding was minimized. One property in particular required

constant attention to mitigate nuisance flooding. Ultimately the project was finished and now

provides a diverse range of habitats throughout the stream and wetland systems.

                            

Education, Outreach, or Public Involvement:

There was close communication with neighboring residents and throughout the design process.

To ensure public access to the site, a series of low impact trails were installed throughout the

site. Since completion of the project, the project site is often visited by County staff as part of

tours. Tour group’s  interests are varied, from fellow stormwater professionals interested in

design techniques, to environmental advocacy groups and local politicians interested in examples

of successful environmental restoration projects. The vast size, convenient urban location, and

varied techniques utilized at the project make it easy to access and tailor tours to individual

groups. The BUBBA award will help elevate this exceptional project’s profile and ensure it

continues to teach the environmental community, and bay area residents, about the importance

and effectiveness of stream restoration throughout the watershed.

To read a complete project narrative and view more photos, please visit the project folder in our Google Drive.

 


First Place   –  2017 Best BMP Retrofit

James Terrace Water Quality Improvement Project

James Terrace Regenerative Stormwater Conveyance

Project Team:

James City County Stormwater Division;

Kerr Environmental Services Corp;

GET Solutions

This project involved the installation of an innovative system of water quality treatment facilities to reduce nutrient and bacteria loads and decrease flooding in a Virginia neighborhood. The three phase project consisted of a bio-retention swale and two regenerative stormwater conveyance channels installed across four private properties. In addition to the water quality benefit, the project restored wetland functions, provided an aesthetic improvement and reduced property flooding.

To read a full narrative and view more photos, please visit the project folder on our Google Drive.

Overview

The James Terrace Water Quality Improvement Project addresses chronic uncontrolled storm runoff

affecting property throughout a fully built-out neighborhood by installing an innovative system of water

quality treatment facilities that reduce nutrient and bacteria loads in the Chesapeake Bay and College

Creek and reduce instances of crawl space and driveway flooding. The three phases of the treatment

system consist of a bio-retention swale and two regenerative (wetland) stormwater outfalls, installed

across four private properties. Combined, these new treatment facilities promote infiltration, restore

wetland functions and reduce 8.63 pounds of phosphorus and 53.18 pounds of nitrogen annually. This

project is being submitted under the Retrofit category since it substantially improves the water quality and

quantity functions within the neighborhood.

The James Terrace Neighborhood is located in historic James City County and is bounded on the west by

the City of Williamsburg and on the east by York County. The highest point in this 1950’s neighborhood

contains the historic Fort Magruder Civil War Redoubts and the intensively developed Grace Baptist

Church property, which has been at its current location since the early 1900’s. When the neighborhood

was developed with ¼ acre lots, little thought was given to managing runoff or protecting water quality

and many lots contain wetlands or intermittent stream channels. As a result, the development has no

stormwater management facilities and the residents are vulnerable to flash flooding or long periods of

standing water. As problems with crawl space flooding and driveway inundation became apparent, James

City County undertook a series of feasibility studies to identify alternatives and options for upgrades. The

County’s appointed Stormwater Program Advisory Committee reviewed the project using their health,

safety and public welfare criteria and recommended funding. Furthermore, the Virginia Department of

Environmental Quality Clean Water Financing and Assistance Program committed 50% funding due to

the project’s cost effective nutrient reductions.

 

Challenges

Success of the project was contingent on the support of the affected property owners. Owners were asked

to provide to the County, at no cost, sufficient easements to construct and maintain the structures.

Property owners were also asked to take on responsibility for removing trash or leaves that could clog the

facilities. The County took on all other maintenance in accordance with its standard BMP maintenance

policies and procedures.

While the property owners were definitely experiencing costly damage due to the uncontrolled runoff,

they were understandably concerned about loss of their limited yard space. Efforts were made to

minimize impacts to yards by the use of retaining walls and previously existing easements. Efforts were

also made to add value by installing attractive native plants to bring color and interest to the yards.

Finally, working in a densely built neighborhood offered a full set of difficulties. There was limited space

for stockpiling equipment and materials. Residents needed access to their vehicles and driveways.

Children needed to be kept safe from the construction. Some residents were without the use of their

backyards for several months. Other residents had trouble recognizing that some plants were planted

rather than weeds and kept mowing new plantings.

Outreach and Community Involvement

The involvement of Grace Baptist Church and its congregation provided an immediate opportunity to

share the concept of protecting water quality through infiltration and native plantings. The Church sees its

participation as an opportunity to give back to its neighborhood. Members have repeatedly made the

Church available for neighborhood meetings. Church leaders report the congregation’s high level of

satisfaction with the project and how it has enhanced the Church’s landscaping. They have become

attentive to rain events and enjoy watching the bioretention facility do its job.

In June 2015, James City County highlighted this and another regenerative stormwater outfall project at a

meeting of the Hampton Roads Planning District Commission Regional Environmental Committee. The

purpose of the presentation was to encourage the use of these types of wetland practices as retrofits in

urbanized areas with shallow groundwater. Through an RSO installation, wetland features are restored

and water quality is protected. Representatives from member communities throughout the Hampton

Roads region attended the meeting and were introduced to the practice.

In October 2016, Chesapeake Bay Foundation highlighted the project in an article about the Virginia

Stormwater Local Assistance Fund

(http://cbf.typepad.com/chesapeake_bay_foundation/2016/10/slowing-the- flow-fixing- flooding-with-

gardens-and- wetlands.html ). This article was seen and shared by many in the neighborhood, the County

and the region.

Project Details

Construction on the James Terrace Water Quality Improvement project began in November 2015 and was

substantially complete in May 2016. During that period, the facilities experienced several short, high

intensity storms as well as approximately 13 inches of rain throughout the month of May 2016.

Stormwater best management practices (BMPs) employed in the neighbothood include a bio-retention

swale along Coleman Drive, a Regenerative Stormwater Conveyance (RSC) Channel at 899 Tyler Drive,

and a RSC channel at 711 Mosby Drive. The bio-retention swale meets DCR BMP No. 9 Level 1 design

criteria and thus has Total Phosphorus load reduction rate of 25%. The RSC channel pollutant load

reduction rates have been calculated using the “Recommendations of the Expert Panel to Define Removal

Rates for Urban Stormwater Retrofit Projects,” October 2012. The pollutant removal rate for the RSC

channel at 899 Tyler Drive was calculated to be 48% for Total Phosphorus, 40% for Total Nitrogen, and

51% for Total Suspended Sediment. The pollutant removal rate for the RSC channel at 711 Mosby was

found to be 18% for Total Phosphorus, 16% for Total Nitrogen, and 19% for Total Suspended Sediment.

The RSC channel removal rates differ based on the design of the pool storage volume, filter bed and the

procedure used to calculate the Urban Stormwater Retrofit Pollutant reduction rates. Also, the RSC

channel at 899 Tyler Dr. has a drainage area of 10.07 acres, while the RSC channel at 711 Mosby has a

drainage area of 15.45 acres. The differences in drainage area compared to the treatment volume for each

RSC channel is a primary reason the pollutant removal rates differ for the two RSC channels. The total

pollutant reduction for all three planned BMPs combined is 8.63 lbs/yr Total Phosphorus and 53.18 lbs/yr

Total Nitrogen.

1483732313_JamesTerraceWetlandExhibit