Rocky Mountain Institute and the STUDIO for Creative Inquiry are sponsoring a technical design charrette aimed at helping communities in the Nine Mile Run watershed manage stormwater in an ecologically-appropriate and sustainable manner. Funded by the Heinz Endowments, this three-day event on Thursday through Saturday, October 15, 16 and 17, will emphasize site and neighborhood-based measures to infiltrate and detain precipitation in order to improve water quality and reduce stormwater pulses into combined sewer lines and streams in the watershed. The sponsors and charrette participants will also seek ways to integrate these approaches with appropriate sewer rehabilitation and ecological restoration projects. By focusing design efforts on several specific sites within the watershed, the charrette will develop measures that are suitable and realistic for implementation in the local context. Participants will also address implementation opportunities and barriers in relevant local codes, regulations, plans, policies, infrastructure programs, etc.
"Charrette" is the architectural and process term for an intensive design workshop. A charrette gathers together stakeholders and experts, typically for two to four days, to develop solutions to a design problem. The word derives from historic design competitions in Paris, where a wagon (charrette) came through the streets to each firm at a time certain to collect designs. It is a highly collaborative, results-oriented, exhausting and exhilarating process.
Innovative solutions to stormwater management require integration of multiple perspectives and types of expertise, including landscape architecture, engineering, architecture, soils and hydrology, public works, planning, real estate development and more. By pulling together people with diverse knowledge as a single design team in a results-oriented forum, charrettes encourage whole-systems thinking and quickly turn that thinking into concrete design ideas. Charrettes are an efficient intermediate step between a general approach or design philosophy and pre-construction architectural or engineering specifications. They are a very effective means of wrestling with a design problem, screening potential solutions, and outlining the look and feel of the best techniques. They allow a client or community to focus its follow-up design energies on the best solutions.
On the following pages you will find the dates and times that your local knowledge and expertise is requested. On Thursday evening, the project teams will outline their ideas concerning issues and approaches to the four specific sites. Community participants will be invited to participate in "break-out" or "round-table" sessions. The goal of this event is tohelp the design teams understand the place and its issues from a local perspective.
On Saturday afternoon, the team will present the results of the three days work. Community members and local officials will then be invited to the break-out tables once again, for a final community discussion of the work and to evaluate the ideas for potential construction as demonstration projects. A final summary will end the discussions.

 

 
 
 

Nine Mile Run Stormwater Management Charette
 

A reception will follow the final summary.

Municipal approaches

Can be funded through local, state and federal initiatives.

• Tree plantings. Studies have shown that tree foliage can hold and absorb or evaporate

up to 35% of the rain falling annually on the diameter of the tree canopy.

• Street narrowing. Common now in new developments, narrow streets calm traffic,

increase green space, improve property values, and reduce impervious area. Some

American communities are narrowing existing streets for the multiple benefits created.

Portland, Oregon calls their effort the "Skinny Streets" program.

• Porous pavements. The techniques are well developed and the performance well tested.

As streets and parking areas are repaved in coming decades, porous paving options should be given strong consideration.

Homeowner Approaches

Can be funded through innovative tax-relief incentives and cost sharing programs.

• Roof leader disconnects. Removing rain leaders from sewers seems an obvious step to

cut stormwater volumes in combined or separated lines. There are various techniques to

infiltrate roof runoff without flooding basements.

• Cisterns. Some roof runoff can be captured in rain barrels or other cisterns and either

used for yard and garden watering, or released to dry wells or other infiltration systems

once the storm passes.

• Turf management. Aeration and other techniques can increase the infiltration rate of

lawns. Certain grass species, by virtue of denser, deeper roots, can improve infiltration.

• Driveways can be modified to increase pervious area in many ways.

• Eco-roofs. A modern variant on the sod roof, with lower weight and easier handling and

maintenance. Eco-roofs absorb water and evaporate it back to the air or grow incorpo

rated plants, greening and cooling the cityscape.

Four teams will address four different sites representative of typical land uses and geographic conditions in the watershed and region. Each team will be given specific design guidelines to meet for improved water management and ancillary benefits.

•"Regent Square Gateway." Public rights-of-way and a former supermarket on Braddock Avenue. Lying at the junction between the developed portion of the watershed and the open space of the lower watershed.

•"Sterrett School." A Pittsburgh middle school building and associated grounds, in a block with several single-family residences, at mid-elevation in the watershed.

•"Edgewood Transit Crossings." A busy street intersection, associated small storefront buildings and residences and a church, bounded by a railroad bed proposed to become a transit corridor.

•"Hunter Park." Municipal playing fields surrounded by homes, in the hillsides of the upper watershed.

A fifth "policy" team will address implementation opportunities and barriers in relevant local codes, regulations, plans, policies, infrastructure programs, etc.

During 1997, the Allegheny County Health Department issued health advisories on 45 days of the recreational boating season urging residents to avoid contact with river water. The need for these warnings traces to wet weather sewage overflows and sewage system bypassing occurring in municipal systems. Combined sewer overflows (CSOs) occur at structures designed to release mixed sewer and stormwater when flows in combined sewer lines exceed system capacity. They are legally permitable under the National Pollution Discharge Elimination System, but must be reduced. The regional sanitation provider, Allegheny County Sanitary Authority (ALCOSAN), is due to release its Long Term CSO Control Plan in late 1998 or early 1999.

Sanitary sewer overflows (SSOs) can result from illegal connections of roof and basement drains and infiltration into cracked or disjointed sanitary sewer lines. Excess flows leak out through cracks or by pushing off manhole covers as pressures mount during wet weather. In addition, when the ALCOSAN regional system was designed in the 1940s, dedicated overflow structures were built into sanitary as well as combined sewer lines, because older urban sanitary sewers were known and expected to include many roof and basement drain connections. Federal and state regulatory agencies now consider SSOs illegal. Responses to the SSO problem have been many. A number of communities have built or are considering water storage tanks and detention basins to hold excess wet weather flows. Projects to rehabilitate cracked sanitary sewer lines or replace those lines altogether are underway or in the works in several municipalities.

Recently the Allegheny County Sanitary Authority and the Allegheny County Health Department joined forces to establish the Three Rivers Wet Weather Demonstration Program. Using federal, local and in-kind funding, this eight-year program will emphasize watershed-based approaches, establish a wet weather management planning process, and award funds to competitively selected projects demonstrating innovative technical, institutional, and financial mechanisms to control sanitary sewer overflows.

As in many urban regions, surface runoff from storms is also a local problem, causing localized flooding and erosion of stream channels. Pennsylvania’s Storm Water Management Act of 1978 (Act 167) requires all counties to develop stormwater management plans for the watersheds in their boundaries. These plans must set forth provisions to ensure that development does not alter stormwater runoff quantities in ways that adversely affect health, safety, and property. At the current time, plans have been developed and adopted by Allegheny County for most but not all of the watersheds in the county. Act 167 plans only regulate new development and redevelopment; they do not address remediation of problems from the existing pattern of development.

Recently, federal regulatory interest in nonpoint source pollution from urban runoff has increased. Urban stormwater runoff carries pet feces, lawn fertilizer and pesticides, oils and greases, trash, particles sloughed from automobile brakes, and pollutants deposited on the city from the air. The U.S. Environmental Protection Agency considers this nonpoint source pollution problem an important national priority, and has recently promulgated new stormwater quality regulations for smaller communities and properties to augment

Hugh Archer. Deputy Secretary. Pennsylvania Dept. of Environmental Protection; Harrisburg, PA.
Tim Collins. Artist; STUDIO for Creative Inquiry; Pittsburgh, PA.
Patrick Condon. Landscape Architect; Moriarty/Condon Ltd.; Vancouver, British Columbia.
State Senator Jay Costa.
Mike Foreman. Policy Specialist; Governor’s Center for Local Government Services; Pittsburgh, PA.
David French. Planner; L. Robert Kimball & Associates; Coraopolis, PA.
*Kevin Garber. Attorney; Babst, Calland, Clements and Zomnir; Pittsburgh, PA.
*Ray George. Public Liaison; U.S. Environmental Protection Agency; Wheeling, WV.
Caren Glotfelty. Policy Analyst; Pennsylvania State University; University Park, PA.
*Mike Hullihan. Director of Engineering; Pittsburgh Water and Sewer Authority; Pittsburgh, PA.
Petra Kuehl. Landscape Architect; Toronto, Ontario.
*Durla Lathia. Chief of Stormwater Planning; Pennsylvania Dept of Environmental Protection; Harrisburg, PA.
Paul Leonard. Aquatic Ecologist; EDAW, Inc.; Atlanta, GA.
Tony Mottle. Planner; Pennsylvania Dept of Community and Economic Development, Pittsburgh, PA.
Jan Oliver. Engineer; Allegheny County Sanitary Authority; Pittsburgh, PA.
Richard Pinkham. Policy Analyst; Rocky Mountain Institute, Snowmass, CO.
*Ed Ritzer. Engineer; Pennsylvania Department of Environmental Protection; McMurray, PA.
John Schombert. Director; Three Rivers Wet Weather Demonstration Project; Pittsburgh, PA.
*Dan Sentz. Planner; Pittsburgh City Planning Department; Pittsburgh, PA.
Jennifer Smith. Engineer; Post, Buckley, Schu and Jernigan; Bowie, MA.
John Stephen. Attorney; STUDIO for Creative Inquiry; Pittsburgh, PA.

Attending the Public Sessions of the Site

Specific Stormwater Managment Options Charrette.

Thursday Evening, October 15

6:30 pm Presentations of urban stormwater issues
7:15 pm Break-out public "round-table" sessions. Teams discuss and exchange ideas, questions, and concerns with local citizens and officials.
8:30 pm Round tables wrap-up.

Saturday Afternoon, October 17

3:30 pm Closing public session: Overview of the charrette effort and brief team pre sentations. Local citizens and officials discuss any final charrette concerns or issues with teams at breakout tables
5:30 pm Reconvene and close.
5:45 pm Reception at Hosanna House.

Refreshments served.