National Mall Union Square / Winning Competition Submission

THE NATIONAL MALL DESIGN COMPETITION

CONTENTS

DESIGN STATEMENT

PRESENTATION BOARDS

DESIGN REPORT

• Response to the Vision for the National Mall

• Respect for the Historic Context

• Environmental, Functional, and Operational Sustainability

• Creating a Welcoming and Secure Environment

• Enhancing the Visitor Experience

APPENDIX / ADDITIONAL INFORMATION

• Historic Assessment

• Spatial Accessibility Report

• Transportation Report

• Civil Engineering Report

• Energy Analysis

• Water Feature Design Narrative

and Maintenance Schedule

DESIGN STATEMENT

Union Square is a focal point in a unique and monumental urban plan, the setting for some of our nation’s most powerful shared memories. It is the ground on which we gather at moments of national crisis and celebration and an iconic public space that expresses our unity. It also challenges us with the question of who we are as a people and a nation.

In the course of this design competition, this question of our national identity has always circled back to the tension of a single nation grounded in its shared ideals and values, yet composed of a diverse and varied array of human experiences, cultures and histories. We believe that Union Square, named in affirmation of the Union after the Civil War, must at its core be a place that acknowledges this tension of America individualism and diversity, as well as our common shared aspirations.

Union Square is a powerful site to expose this tension a vital terminus to the Mall and forecourt to the Capitol. It carries with it the genetic code of L’Enfant’s idealized plan. But its uses, as a place for assembly, celebration and protest, make it a place distinctly of our time. This design competition provides the opportunity to re-envision this public plaza with a complexity and richness that addresses who we are today.

Each generation that builds on the Mall has confronted L’Enfant’s vision and each has brought to it the values and sensibility of their own time and place; in some cases the response bordering on disregard, while in others a reverential re-interpretation and extension of its strongest features. Union Square as it stands today is a broad and un-modulated plane of water and lawn, and we see the opportunity to not only re-interpret and extend the vision of L’Enfant and the urban clarity of his plan, but also to overlay and enrich this plaza with other less formal spaces; features and textures that respond to the underlying natural landform of the site, the day-to-day patterns of movement through the city fabric and the diverse needs and desires of the people who populate this place throughout the year.

Much like one’s first impression of the Mall itself, the initial reading of the new Union Square is that of a simple and symmetrical urban space. Only upon further study does the plan reveal a layer of subtle responses, site specific gestures and distinct spatial environments that are diverse, yet combine to enrich and support the formal gesture of the whole.

VACANT SITE

Today, Union Square is an underwhelming and under-populated space. However, it remains a focal point in a unique and monumental urban plan, and a place of potential engagement for hundreds of thousands of visitors.

NATIONAL SYMBOL

The emotional resonance of the Union Square site arises from its setting, beneath the US Capitol and opening onto the long perspective down the National Mall to the Washington Monument. These are iconic views, deeply etched in the collective memory of our nation.

EVERYDAY LIFE

The power of Union Square lies in its ability to serve as a public space for everyday interactions as well as national events. By making spaces that embrace the individual’s need to explore, play, and relax, Union Square will become a significant place in the minds of residents and visitors where individual encounters contribute to national identity and amplify the impact of major events.

The Continuity of the Urban Plan

The National Mall is a work in progress and the redesign of Union Square is yet one more in a series of plans to join the Mall and the Capitol Grounds in a significant public space and terminate the major urban axes of Pennsylvania, Maryland and Louisiana Avenues. L’Enfant originally envisioned that these avenues would terminate in a space, not a building, but the US Capitol, substantially enlarged over the course of the nineteenth century, now provides a monumental focus for these urban vistas.

With the McMillan Plan of 1901, a century of ad hoc development was slowly reclaimed with the formal clarity of L’Enfant, re-interpreted in a City Beautiful plan. This plan engaged the picturesque Olmstead grounds of the Capitol, yet Union Square remained unresolved as an urban space. The McMillan Plan re-imagined Union Square as a variant of the Place de la Concorde, suggesting a hard urban plaza at this critical juncture. The 1939 Mall Plan instead extended the bucolic landscape of Frederick Law Olmstead’s Capitol Grounds and integrated the Memorials to Grant, Garfield and Peace. Finally in the 1960s construction of a highway tunnel led to the current condition, a monumental reflecting pool and lawn, whose spare and neutral geometry seem to belong neither to the formal parterres of the Mall nor to the naturalistic landscape of the Hill.

The legacy of the urban plan is a decisive feature of this design proposal. Union Square is a formally ambiguous space, not fully part of the Mall yet not an extension of the Capital Grounds. This design proposal accepts the axial geometry and formal planning of the National Mall as a defining gesture of the new design, but overlays a series of secondary spaces and axes that address the Capitol Grounds, the various Memorials, the surrounding streets and movement and activity of people.

The re-orientation of the reflecting pool to the east-west axis reinforces the powerful vista of the Mall. Likewise the axes of Pennsylvania, Maryland and Louisiana are preserved and subtly enhanced with refinements to their scale and strengthened definition to their edges. But other aspects of the design are more complex. The tree-planted parterres of the Mall extend across Third Street to frame the site, but further east become stepped terraces flanking the pool. These terraces introduce a significant area of permeable hardscape to the site, but are overlaid with trees to provide shade. As one moves north or south of the main axis, the landscape becomes more complex and varied, providing the opportunity for more intimate places for rest and relaxation. Across Pennsylvania Avenue on Site 575, the landscape becomes even more varied, with the potential to provide an ever changing demonstration of innovative technologies and design.

The Meaning of Union Square

The formal order of Washington’s urban plan is underscored by an equally powerful set of connections and thematic references evoked by its emotionally resonant monuments and memorials. These structures, especially the Lincoln Memorial, bring an emotive content to the urban experience by virtue of the stirring public events associated with them, as well as through our own personal encounters. In the years following the Civil War, Union Square was conceived as the representation of the enduring bonds of our political union and the continuity of the United States. Anchored by the Memorial to Grant and his Army, Union Square forms a physical and thematic counterpoint to the Lincoln Memorial at the Mall’s western terminus.

The legacy of the Civil War is far-reaching, and though its memory may have grown distant, the resonance and value of “union” remains a strong and powerful theme for this space, particularly as our nation embraces its increasing diverse population and their dreams of justice and opportunity.

This location also carries with it the iconic presence of the Capitol and its dome. The imagery of this building embodies the spirit of our representative democracy, both our ability to unite in crisis and purpose, and the dialogue and dissension that is part of a free society.

Our design for Union Square achieves two symbolic aims. It symbolizes unity, through the preservation of the open vistas to the Washington monument and the Capitol, and it evokes a welcoming presence as the forecourt to the “people’s house.” The new reflecting pool visually extends to Third Street, and the simplicity of the central space frames an iconic view, one that evokes unity and solidarity. But equally important, the design creates places that accommodate and celebrate individualism and diversity at the scale of daily life. In contrast to the bleak monumental national plazas of an authoritarian state, one should find in Union Square a rich array of environments that accommodate joy, domestic tranquility, dialogue and creative expression. Democracy is a simple idea, but can sometimes be a messy business. The design for Union Square welcomes visitors with a monumental scale, but it also provides comfortable places for a diversity of experiences and voices while maintaining a singular identity at the heart of the composition.

A Model for Sustainability

Planning and designing this space with attention to its intensity of use, selecting the right materials, and thinking of innovative strategies to minimize the consumption of resources and energy are vital to achieve a model project. The overriding goal of sustainability in this design is achieved through the creation of durable outdoor spaces that serve their intended purpose and utilize materials and systems that can be efficiently maintained through the life cycle of the project.

The team has explored alternative sources and efficient uses of water and energy for the whole site. A greater diversity of planting has been introduced into the tree canopy, and the design employs a greater proportion of ground cover and shrubs in lieu of lawn. The contours of the site are designed to increase retention of storm water in selected areas, achieving zero discharge into the city system. At the same time the design balances cut and fill and anticipates the reuse of some existing materials such as the massive limestone coping stones of the current pool.

The large scale water feature that defines the site was conceived with a holistic strategy with regard to water conservation, energy use, visual appearance and programmatic function. The new pool uses a significantly reduced volume of water, and relies on the harvesting, filtration and storage of groundwater.

The proposed Youth Park on Site 575 is envisioned as a garden with potential to host demonstration projects for sustainable design, within a framework that conforms to the objectives of congressional legislation concerning the site and as a counterpoint to the Botanic Garden to the south.

Developed as a “Ground for Emerging Voices,” much of this landscape could be temporary in character, and in a program that promotes young talent, used to showcase technologies, plants and materials as part of an ongoing mission of environmental stewardship

A Place for Gathering and Celebration

By virtue of its role as a forecourt to the Capitol, Union Square is ideal as a gathering place for events of national significance. The charge of the competition brief is to design a space that accommodates celebrations, demonstrations and special events of varying size, and with varying levels of infrastructure and temporary facilities, improves security and operations, and reduces pressure on the overtaxed Mall lawns.

This design acknowledges the need for a significant area of hardscape that can address the intensity of use for special events, but also the need for a variety of scales and modes of use. The major focus for large assemblies will continue to be the central, monumental space defined by the reflecting pool. This pool, which extends from Third Street to the Grant Memorial, is a shallow (2”) sheet of water over a paved surface that can be drained in sections to create a range of differently sized assembly spaces. Paved paths running diagonally at the surface of the pool serve the need of pedestrians to traverse this large water feature, but they also allow people to inhabit the water’s surface, enlivening and humanizing this formal space.

In the center of Union Square adjacent to the main pool are a series of stepped terraces which can be used for gathering and assembly, and whose permeable surfaces are interspersed with trees to

provide shade and shelter. The terraces and the associated low walls create transitional spaces between the monumental scale of the central axis and the park-like settings to the north and south.

Grant remains a major focus of the monumental core of Union Square, but unlike the current condition, where the Memorial is isolated by the vastness of the water, the new design creates a defined outdoor room and usable spaces in front and in back, enhancing accessibility and providing a stage or focal point at times of assembly. To the rear of Grant, the plinth has been extended to the Capitol Grounds, creating a platform oriented to the slope of the West Lawn that can also serve as a potential stage and provides universal access to the monument itself.

An additional and significant place of assembly has been created at Pennsylvania Avenue The street remains at its current width, but parking and traffic have been eliminated. This critical visual axis can be read more clearly and the street reclaimed as an important public space that also provides one more key event space that can be part of the larger network of spaces within the larger National Mall plan. The Memorial to Peace has been moved from its current location to the west to become part of this linear public plaza.

A Place for Recreation and Daily Life

The east west axis of the Mall defines the monumental core of Union Square, reinforced by the reflecting pool and extended allees of trees. But a substantial portion of Union Square lies to the north and south, extending to the Botanic Gardens and Site 575. It is these spaces that provide an opportunity to introduce a more diverse and less monumental character to the site, and to create environments that invite a more intimate scale of interaction. This contrasts with the existing condition of Union Square, which achieves its monumental identity at a steep cost. Its center cannot be occupied, and its edges are undefined. Connections and circulation to and through the site are poor.

The new design opens the site with a series of new paths and pedestrian connections, and introduces a north-south cross axis alongside a water feature, which in contrast to the large reflecting pool, is a linear, active, and bubbling ribbon which leads the visitor away from the central core into a series of green and shaded spaces. These spaces in turn link

to the Botanic Garden to the south (across a narrowed Maryland Avenue) as well as to the proposed Youth Park on Site 575. The program for the Youth Park (Ground for Emerging Voices) offers an opportunity to explore a number of ideas articulated in the congressional legislation that preserved the site, including the ability to showcase sustainability. A potential building site at the corner of Third Street and Constitution Avenue can support this program and also serve to define the southern terminus of Louisiana Avenue.

Within the landscape of the site, edges are defined to create rooms that operate at multiple nested scales. Subtle changes in grade form terraces and low retaining walls. Planted form further defines the spaces within, utilizing the existing mature trees on the site. Edges are strengthened at the perimeter; the palette is diversified and materials and plantings grouped to reinforce the different identities of the constituent spaces.

Spatial Definition - Existing Spatial

A Place of Our Time

We see the United States as a place of energy, diversity and change: a rich and fractious population bound by a shared commitment to tolerance, freedom and opportunity. Union Square must represent this complex condition, our unity and shared commitment, but also the diversity and richness of our people and history. It is both a place of iconic reverence, as well as an active square of public life.

Like a mosaic, a work that forms a unified composition, yet composed of distinct and individual pieces, Union Square is built from a richly textured array of spaces and human experiences, yet achieves the singular identity and power necessary for its symbolic role in our nation.

PRESENTATION BOARDS

DESIGN REPORT

RESPONSE TO THE VISION FOR THE NATIONAL MALL

The National Mall has been described as our nation’s front yard and its democratic stage. Union Square, by virtue of its location fronting the US Capitol, is perhaps an even more concentrated expression of this powerful presence in our national identity. Like the Mall, Union Square plays an essential role as foreground to iconic national symbols, it carries a rich historic legacy and it functions year round as an vibrant ground for the activities of daily life.

The design responds to the goals and objectives that are part of an overall vision of the National Mall Plan, supported and enhanced by similar aspirations of the Architect of the Capitol. This proposed design creates a major civic square which addresses the underlying history of the site, a public space which frames and preserves the iconic view of the US Capitol. The use of water on the site is re-imagined

as a feature that is at once formal and monumental, but also inviting and engaging at a human scale. This water feature also provides the ability to serve as a major place of gathering in an adaptable and flexible manner. Designed as a flat and shallow pool, discrete sections can be quickly drained to create paved plazas for major events, but on most days the pool offers a transitory and luminous surface that reflects the sky, trees and major monuments of the city. The design of a somewhat smaller monumental public space at the center of Union Square in turn provides the opportunity to introduce a diverse array of new landscape environments that accommodate the activities of daily life, spaces which offer visitors, Congress and staff relief from the hot humid climate and surrounding traffic, and provide a more intimate scale for the small groups that constitute the bulk of visitors to the site.

Civic Square

The role of Union Square as foreground to the Capitol involves framing and presenting an iconic view, one which is reflected in a large pool and seen from a variety of vantage points and distances. The square also incorporates the extension and termination of Pennsylvania and Maryland Avenues, the former a national ceremonial route and major thoroughfare of the city. Finally the Union Square is the setting for the Grant Memorial, a sculptural group that anchors its identity and definition as a place that reflects the Union’s survival in the aftermath of the Civil War.

This new design enhances our view of the Capitol by extending the pool towards Third Street, allowing its reflective surface to be perceived from the edge of the site. The extension of major pedestrian walkways from the Mall allows for an east-west procession through the site that continues to engage views of the Capitol. Two formal groupings of trees along Third Street frame and focus the view from the Mall. Shallow stepped terraces to the north and south of the reflecting pool also serve to maintain focus on the axial perspective

of the Mall, and subtly screen more informal spaces to the north and south.

By reducing the overall size of the water feature and shifting its orientation onto an east-west axis, the pool becomes less of a barrier to pedestrian circulation, and allows for greater connectivity to the Capitol Grounds and Grant Memorial. The reduced pool dimensions also provide greater accessibility to the Grant Memorial which is no longer moored at sea, but fronted by a pedestrian plaza. To its rear, the Memorial’s plinth is extended to provide an appropriately scaled space. Both plazas can be used to support events held on the drained pool surface or the Capitol Grounds.

Spatial

Water

Water has always played a prominent role in the vision of the National Mall. Before the establishment of the city Tiber Creek coursed through the site, and L’Enfant had planned to redirect its waters into a cascade and pool at the foot of Capitol Hill. Instead the creek was canalized to run beside Third Street, eventually becoming an open drain, and by the 1870s an enclosed sewer. From 1878 to 1927, the Bartholdi Fountain was located here, a sculptural water feature illuminated by gaslight, and the 1901 McMillan Plan proposed a reflecting pool on the site oriented along the axis of the Mall. Not until the 1969–1971 rebuilding of Union Square was a major reflecting pool constructed, which serves as a counterpoint to the western pool at the Lincoln Memorial.

Water enables the site to attain a monumental presence and strengthens its association with the Capitol. This design maintains the formal power of the central reflecting pool, but also introduces a human scale to its edges and allows visitors a much more intimate relationship with the water. A low bench-

height parapet at Third Street gradually diminishes to an edge flush with the paved walk as one walks east. The pool is shallow, approximately two inches deep, a safe and inviting depth for play. The pool is traversed by flat paved paths at the level of the water surface which allow visitors to occupy the center of the pool and be viewed against the plane of the water. Selected areas of the pool are equipped with small jets to activate the surface. All these features result in an intriguing contrast between a vast and formal expanse of water and a humanely scaled visitor experience that is both inviting and unanticipated.

In addition to the reflecting pool a linear water feature runs though the site to engage pedestrian movement in the north-south direction. This feature contrasts in character with the main pool as it is a flowing and active water surface. Both pools have been designed with attention to achieve an overall reduction in water use, ease of maintenance, and energy efficiency, which is further discussed under Environmental, Functional and Operational Sustainability.

Gathering

Key to its role as a place of national identity is the ability of Union Square to accommodate large gatherings of people for special events such as first amendment uses, festivals, concerts and the inauguration of the President. However these large scale gatherings, though an important feature of the space, are not its typical use, and the challenge remains as to how to design a sustainable,durable and flexible national plaza that is also inviting and active when it is not being used by thousands of spectators.

The proposal of this design is to create multiple spaces for assembly, including a linear pedestrian promenade at Pennsylvania Avenue that can accommodate a number of events on a permanent hard surface. For the largest events the main reflecting pool can be converted into a number of configurations for gathering by using the cross- paths to divide the pool into distinct sections. Finally, the stepped terraces to the north and south of the pool allow for medium sized assemblies to use these spaces for gathering.

By increasing the paved area to the west of the Grant Memorial, this space can be used as a stage or focal point for large assemblies. To its rear, the extended plinth of the Memorial can serve as a concert stage facing the informal seating on the West Lawn of the Capitol Hill.

Typical day

Multi-Performance Event

Large Festival with Tents

Small Event

Large Island Event

Medium Event

National Assembly Event

Medium Festival

Capitol Grounds Event

Large Event

Pennsylvania Avenue as a Public Promenade

Daily Life

To achieve the life and activity essential to the spirit of this design, meaningful pedestrian connections must link Union Square to the surrounding city, and internal paths and walks animate and enliven the spaces of the new park. The current condition of Union Square is arguably deficient in these areas, resulting in awkward detours and worn dusty paths in the lawn. The two major east-west routes of travel essentially border parking lots. The major north south path, at the western edge of the pool, also terminates in parking and does not provide meaningful connections to the surrounding urban fabric.

Initial studies of pedestrian movement suggest the importance of linking to the east-west walkways of the Mall across Third Street. There is also a significant benefit to being able to traverse the site diagonally, responding to the movement of pedestrians between the Mall Museums and the Capitol Visitor Center.

New pedestrian paths will provide access to secondary destinations within the site. South of the Main Pool, the landscape can be used to extend demonstration plantings of the Botanic Garden. To the north, these plantings can relate to Site 575, which interprets the Youth Park as a national garden of emerging voices. The character of these spaces is less formal; defined by planted form they are smaller in scale and sheltered by trees that provide places of shade and rest.

The opportunity to reduce or eliminate vehicular traffic will significantly improve the environmental quality (as well as security) of Union Square. The design proposal suggests the relocation of tour busses and vehicular traffic to Third Street, limiting the existing internal roads to service use or limited bus drop-off. Third Street can be reduced in width by one traffic lane which subtly improves the sense of connection between Union Square and the Mall.

A civic square fronting the Capitol has been envisioned from the initial conception of Washington’s urban plan, yet this space has been almost continuously transformed and re-imagined for over 200 years. Its historic evolution provides important clues to this design, which is presented not as a radical departure from precedent, but as part of an evolution that builds on the work of those who preceded us.

Memorial and the western horizon. In achieving these objectives, this design concept for Union Square re-interprets and extends the vision of L’Enfant and successive historic plans.

UNIFIED GROUND

The proposal for Union Square carries forward the essential, historically grounded principles inherent to the site’s evolution: it retains the site’s symbolic function as a memorial to the Union; it reinforces the east-west axis of the Mall; it treats Union Square as a transitional area between the Mall and the Capitol Grounds; it forms visual links between the adjacent historic landscapes; and it frames and defines the historic vista from the Capitol to the Lincoln

The design concept re-establishes the site’s historic function as a transitional space between the Mall and the Capitol Grounds. A rectilinear reflecting pool, fitting the Mall geometry and setting, extends the spatial configuration of the central grass panels of the Mall. Circulation patterns will follow the Mall’s primary east-west axis and form a visual connection to the Capitol Grounds. The placement of trees in massings north and south of the Grant Memorial and the reflecting pool provide a transitional element between the rectilinear grass panels of the Mall’s central landscape and the picturesque groupings of trees on the West Lawn of the Capitol.

History of Addition and Evolving Priorities

symmetrical

Framed

Central axis frames monument

Planting defines site perimeter

Landscape connection between Union Square and Union Station

Relocated Botanical Garden

Ground

Central space replaced by large reflecting pool maintaining axial view, but eliminating circulation along the central promenade from Mall to Capitol Grounds

Axes of Pennsylvania Avenue and Maryland Avenue converted to parking lots

East-west pool extends central promenades to Capitol Grounds while maintaining reflection

North-south water and path cross axis

Expanded gardens hold site edges

The power of Union Square lies in its ability to serve as a public space for everyday interactions as well as national events. By making spaces that embrace the individual’s need to explore, play, and relax, Union Square will become a significant place in the minds of residents and visitors where individual encounters contribute to national identity and amplify the impact of major events.

By locating a new reflecting pool at the east end of the Mall as a counterpoint to the Lincoln Memorial Reflecting Pool to the west, the design respects the McMillan Plan vision for the Mall Its form and placement strengthens the conceptual symmetry of the Mall’s east-west axis and sustains a historic legacy of water on the site dating back to L’Enfant and Tiber Creek.

The design recognizes Pennsylvania Avenue the “Avenue of the Presidents” as a National Historic Site and national ceremonial route by eliminating the street parking that currently detracts from the Avenue’s significance. Although the final block of Pennsylvania Avenue closest to the Capitol will be repaved and transformed into a pedestrian promenade, historic aspects such as the street width, lighting and trees will be maintained.

Maryland Avenue is treated as a significant radiating avenue of the L’Enfant plan by eliminating street parking, allowing the historic continuity of the avenue to be read more clearly. Although the segment of the roadway adjacent to Union Square will be decreased in width to allow for additional sidewalk and street trees, the design retains the avenue’s historic alignment.

The design maintains the Grant Memorial as a focal point of the square. The Memorial will remain in its current position demarcating the east end of the Mall and overlooking the grand vista to the Lincoln Memorial. The site’s relation to the Capitol will be strengthened by extending the steps of the Grant Memorial to the east, creating a “platform” or “stage” to encourage participation with the west lawn of the Capitol Grounds.

The design draws on the contextual landscape to incorporate tree masses in a manner that frames historic axial vistas from the Grant Memorial and the Capitol and radiating vistas along Pennsylvania and Maryland Avenues significant aspects of the L’Enfant design. Historic “witness” trees at the northwest and southwest corners of the site, some dating from the Botanic Garden plantings, will be retained.

The historic alignment of Second Street West is integrated into pedestrian paths through the site on either side of the reflecting pool.

The design moves the Peace Monument and Garfield Memorial into the “pedestrian realm” of Pennsylvania and Maryland Avenues, altering the Olmsted plan for the Capitol Grounds.

Maryland Avenue

Maryland Avenue

Elm Character Mix

Museum Mix

Street Tree Character Mix

Native Oak mix

Tree Canopy

Ceremonial Canopy

Native garden canopy

Existing

The number of trees in Union Square increases 750% and builds on both the existing species and heritage trees currently on the site as well as increasing diversity through the introduction of multiple native trees. The canopy provides ample shade for relief on hot summer days.

Pennsylvania Avenue

Currently filled with parking & unusable for pedestrians

Pennsylvania Avenue

Returned to the people as pedestrian boulevard

Tree Canopy and Contextual Landscape

Pennsylvania Avenue as a Civic Space

ENVIRONMENTAL, FUNCTIONAL AND OPERATIONAL SUSTAINABILITY

The design proposal includes a high performance, integrated approach to meeting the infrastructural needs of the renovated Union Square site. From top to bottom, a suite of sustainable interventions will contribute to creating a site and water feature with an extremely small water footprint (a facility with a very low impact on its community’s precious water resources) that is durable and easily maintained, and also reduces demand for energy and natural resources. The project will serve as model for 21st Century public facility and infrastructure design.

Civil Infrastructure

The main site infrastructures studied by the team and its civil engineer in the design proposal, water and earth, have been designed to have the lowest impact possible on natural resources and overtaxed municipal infrastructure. The design proposal utilizes an Integrated Water Design approach and Low-impact Soils Management strategy.

Union Square Water Resources History

Much of today’s Union Square site was once Tiber Creek, and one still hears that Tiber Creek “is running under the site” or “is running under the Capitol Lawn” Unfortunately, Tiber Creek has not flowed as natural clean water since it was first combined with the city’s sewage system more than 150 years ago. Natural Tiber Creek water is no longer available for use at Union Square, however its history has inspired us to explore new opportunities for water display and conservation.

Like most urban areas across the country, Washington for the past 150 years has dealt with water-related utilities in three distinct “silos,” whereby the city’s drinking water supply, sewage treatment and storm water management systems have been planned with little regard for potential synergies between these three water “resources.” This conventional approach led to the development of mega, centralized water and sewage treatment plants whose charge has been

to meet the needs of the entire city in centralized locations. Moreover, storm water runoff is handled with sewage in a combined system which cannot adequately handle the combined load, even in modest storms, leading to combined sewage overflowing to the rivers. Billions of dollars are required to retrofit the existing combined sewer network to preclude these overflows, billions that city coffers simply do not have. The conventional approach has proven to be both environmentally and economically unsustainable.

Integrated Water Design Approach

The design proposal utilizes an Integrated Water Design approach that avoids the conventional silo approach to water resources engineering. This approach considers all the water needs or “demands” of the project and compares them to all the possible water “supplies” available at the project site. The first cost and annual operations and maintenance costs of numerous sustainable water resource strategies are compared to one another and to the conventional approach to determine the most cost effective and environmentally responsible strategy for the project. This approach yields more “decentralized” water resource solutions that reduce water and sewer utility bills and redirects those monies to pay for on-site systems and their long-term operations and maintenance. In addition, these onsite systems reduce the burden on overtaxed municipal systems.

Irrigation Strategy

The design proposal will require no city water for its irrigation. Instead rainwater will be harvested from site areas and surrounding streets and held in cisterns under the landscape. To arrive at the best value alternative, numerous strategies were compared against the baseline approach of buying water from the city (which when projected out over 30 years at current escalation rates will cost $3.6million). Implementing the proposed strategy will cost approximately $230,000, it will payback at year 20 and yield over $528,000 in long term savings.

Water Feature Strategy

The first sustainable water strategy for the main pool was to right-size its footprint and depth. A comparison of the existing feature to the proposal shows that the new water feature has 38% less area and 93% less volume than the existing feature, which means that it will use significantly less water.

Next, a strategy was identified for feeding the water feature that will require no city water. Instead groundwater will be harvested from a shallow well (or potentially from the I-395 tunnel dewatering system) and put directly into the recirculation system to replace water lost through evaporation. In addition, the water feature mechanics include enough capacity to enable all of the water feature areas to be drained down for events without having to discharge the water to the sewer. After events, the same water will be put back into circulation.

To arrive at the best value alternative, numerous strategies were compared against the baseline approach of buying water from the city. The current fountain requires approximately 1.3million cubic feet of water annually to operate. When projected out over 30 years at current escalation rates this will cost $8.7M. Implementing the proposed strategy will cost approximately $75,000, it will payback at year 8 and yield over $1.1M in long term savings.

Holistic Water Stewardship Plan

The final integrated water feature and site water plan requires no city water or sewer services to operate. The water feature is fed from a shallow well in its equipment room. Reserve storage in its recirculation system allows this water to hide from view when needed, without losing this water forever by sending it downstream to the wastewater treatment plant.

Rainfall that lands on the site is directed to underground, gravel cisterns that hold this resource in their voids until the irrigation system extracts the water for use. If the cisterns are full they send rainfall directly to the infiltration areas where the excess rain is percolated back into the ground. This recharge is in balance with the intermittent ground water withdrawal for the water feature supply.

The collection of rainfall is carried out both passively and actively. First, the proposed site reduces impervious cover by 1.4 acres (or almost 16%). This allows much more rainfall to percolate directly into

the ground instead of becoming overland flow. Any net percolated flow from pervious areas is collected in passive and shallow underdrain systems, while rain from plaza areas is collected in shallow trench drains. These systems ensure that the harvested rain is kept high in the ground as it is conveyed to the cisterns, which, in turn, minimizes the amount of excavation required for cistern installation.

Rain from the abutting streets is collected in two key stormwater gardens where rain is cleansed prior to it being delivered to the cisterns. These demonstration gardens will be both artful and academic, envisioned to be in place for perhaps 3 years at a time, all the while being monitored for performance and enjoyed as an amenity. The water strategy for this design exceeds federal requirements and other industry benchmarks such as LEED and the Sustainable Sites Initiative, achieving zero water discharge beyond the 100-year storm. From all water resources vantage points, the proposed design will be a model for 21st Century water stewardship.

Soils Strategy

The low-impact soils management strategy employed in the design proposal seeks to reuse all excavated material on site and only import special earthwork materials such as gravel. This approach minimizes construction impacts and contains them within the site (reducing congestion on surrounding streets, noise and CO2 emissions).

In order to situate the cistern and infiltration gravel at an elevation low enough to accept site runoff by gravity, soil will be removed and stockpiled, gravel will be installed and the same soil will be put back over the gravel. Careful grading design eliminates any need for earthwork disturbance around the existing Heritage Trees that will remain.

Site 575 / “Ground for Emerging Voices”

As a park dedicated to innovative demonstrations of sustainable development, site 575 has the potential to celebrate the remarkable confluence of today’s water resources solutions, 150 years of large-scale urban infrastructure and the 200-year legacy of the Tiber Creek watershed. This site is immediately adjacent to the historic mouth of the Tiber Creek and sits at the confluence of the city’s separated stormwater and the combined sewer systems.

A separate life-cycle cost analysis was carried out for the proposed building and grounds at Site 575. An onsite ecological wastewater treatment system and reuse of its effluent will meet all buildings and grounds water demands. To generate enough reclaimed water to serve the irrigation demand of the site, the EWT will be sized to treat both buildinggenerated sewage and sewage that is “mined” from the historic combined sewer that passes beneath the site. While implementing these strategies will cost around $790,000, these will payback at year 18 and yield over $2.7million in long-term savings.

The overall infrastructure continuum at this site mixes new decentralized strategies with an extraction from the historical infrastructure, enabling an even greater unburdening of the overtaxed system than could be carried out by the site facilities alone. This could truly be a place to celebrate and interpret new infrastructure meeting old and the two working together to meet the challenges facing growing but physically aging 21st century urban areas.

Site 575

Alignment of existing and proposed infrastructure

Water Features

The goal of a new water feature at Union Square should be to produce a modernized, more sustainable water program one which recreates the grandeur and scaled magnitude of the old reflecting pool while also allowing large, discrete areas of display water to be drained and stored singly or in groups, thereby opening up previously unavailable Mall geography to public events.

Main Reflecting Pool

The main reflecting pool is actually a group of five distinct distinct pools, separated by diagonal and axial walking paths. Viewed in plan the group as a whole forms a large rectangle, whose long axis stretches from near the front of the Grant Memorial to Third Street. The pools are of two types: (1) shallow one to two-inch deep reflecting pools with gradually sloped edges, and (2) similarly shallow pools with sloped edges, but which also contain patterned layouts of flush-in-floor water jets.

Water is supplied to the pools through floor fittings, water jets, or some combination of the two. Water then flows into grade-level slots surrounding each pool, and then into a large hidden storage reservoir, thus completing the hydraulic circuit.

As discussed above, an important feature of this design is that it allows some or all of the five pools to be selectively drained so that the space can be used for event staging. The un-drained pools would continue to operate normally. Small or large events can be accommodated, depending on the number of pools being drained.

North-South Linear Fountain Cascades

Four smaller, narrower elements are positioned perpendicular to the main pool feature, and consist of two Basins and two Stepped Cascades. One of the basins is located in Site 575. There are two stepped cascades located on either side main reflecting pool. All the fountain displays will be served from a centralized equipment space. This 14’ x 45’ room will be an underground vault located in the southeast section of the site. It is in close proximity to Maryland Avenue, facilitating easy access for routine maintenance activities.

The water feature can be completely drained to the reservoir below for events, and later refilled from the reservoir, creating a closed system

JETS

POOLS

PLAZAS

RESERVOIR

Water Feature Sustainability

Increased sustainability typically comes from optimization of three factors: (1) energy conservation; (2) water conservation; and (3) minimization of chemical additives. In order to minimize energy consumption, we use variable speed pump motor drive (VFD) technology which allows the fountain operator to slow the pump so that only the energy required to operate the display is utilized reduced flowrates are produced by slower pump speeds. As outlined in the Integrated Water Design Approcah, the water feature will minimize reliance on potable water sources.

A third sustainable water feature will be to utilize a fully automated, regenerative DE (diatomaceous earth) type filter to eliminate backwash (cleaning cycle) related discharge of chlorinated water.

The net results are: (1) the sewer system is not burdened with high backwash rates typical of standard filters; (2) chemicals are therefore not wasted during backwashing, which also lowers environmental impact; and (3) water is conserved due to the lack of a standard backwash cycle, which would otherwise dump thousands of gallons of water each time the filter backwashes.

Given that the majority of these water features will see some form of human contact, they will likely require chemical treatment similar to that of a public swimming or wading pool. That being said, our design will likely also utilize a non-chemical based ozonator to back-up chlorination and thereby reduce chlorine demand.

Energy

An important aspect to the sustainability of the site is reducing the energy and carbon footprint. The strategy for energy reduction has been developed to firstly reduce on-site energy usage through efficiency measures and intelligent controls. Once site energy intensity is decreased implementation of renewable and clean energy technologies will be used to offset the remainder.

The lighting design will continue to respect the current brightness hierarchy of the Capitol and Washington Monument as primary focal points of the Mall. The proposed design will not detract from these monuments, but instead enhance their visual prominence.

The majority of the site energy savings comes form lighting energy reductions and high efficiency water pumps. By switching from typical metal halide lamps to LED lamps and electronic ballasts, energy usage can be reduced by nearly 50%. This savings comes form more efficient lamps and enhanced controls which limit light levels to only the necessary amount for illumination at certain times during the day.

The existing Mall light poles will be extended into the site and engage the new plaza, reinforcing the emphasis of the east-west axis. The historic light poles the mall will use LED lamps, but we recommend further exploration of better shielding and dimming (during late hours) of the newly introduced existing LED lighting to preserve glare-free nighttime views of the monuments and to save additional energy.

supplement reductions in energy use, the team investigated the use of conventional renewable energy technologies such as solar and wind. We found that it would not be feasible to offset all the energy usage with these systems. A much more practical approach to clean energy technology would be to install a fuel cell system sized for approximately 100 kw. These systems are low maintenance and produce electricity with very little environmental impact. The units would be connect to a natural gas fuel source but do not use combustion to produce energy, instead relying on a chemical process. Because these systems are inconspicuous, we would also consider including a more visible clean energy system to raise public awareness. The systems under consideration are Micro Wind Turbines, Solar PV Paving systems, Piezoelectric pads, described in the Appendix in more detail.

A SECURE AND WELCOMING ENVIRONMENT

A sense of security and safety is a vital to the enjoyment of all public spaces and essential to creating a welcoming environment. The proposed design strives to improve site security through careful attention to clear lines of sight, multiple points of access in and out of different spaces, and strategically planned and appropriate site lighting.

The proximity to the US Capitol also necessitates the creation of a discrete set of perimeter controls that can be implemented quickly at critical moments by the Capitol Police. Our approach has been to integrate a fixed secure perimeter into as much of the perimeter as possible using the existing fence and building line of Botanic Garden on the south, the edges of the proposed new building on Site 575 on the north and between them integrating low walls within the edge plantings on Third Street and Constitution Avenues.

At points of entry and at the central axis, we utilize retractable barriers. After further dialogue with Architect of the Capitol, we could propose the alternate use of squad cars as temporary barriers.

Security Wall

Capitol Security Temporary

Bollard

Retractable Barrier

Security

The expanded secure perimeter is integrated into existing and proposed site features to offer flexible security scenarios while reducing the visible presence and perception of barriers for visitors to Union Square.

ENHANCING THE VISITOR EXPERIENCE

The design replaces a vast and inaccessible space with a network of interconnected, variably scaled spaces that provide a range of experiences and accommodate a variety of uses.

Within each space, proportions are modulated and edges and circulation are defined to create more comfortable relationships between individuals and the site. For example, the edges around the Grant Memo-

rial are more clearly articulated and create a sense of enclosure from which one can comfortably occupy the central axis of the Mall. Perpendicular to that axis, the re-introduction of Second Street as a pedestrian connection is supplemented with a series of smaller scaled water features that draw the visitor through the site. Designed as stepped cascades, they provide animation and sound, in a shady environment creating a finer texture and more intimate experience.

Within the central space, beyond the ability to hold different events, the fountain itself can become an event and a draw. The ability is provided to animate the fountain with jets for different uses. For example, the central triangular panels could be drained and jets turned on summer weekends as a draw for families and children. Alternatively the water jets in the panel at the base of the Grant monument could be used in a more formal way to mark special celebrations, like the Fourth of July.

Finally, the cross-linking of the north and south edges of the site to the Botanic Garden and the proposed “Ground for Emerging Voices” on Site 575 provide an opportunity for additional programming, interpretation and education activities on the site that helps to make Union Square a more rewarding repeat destination.

APPENDIX

Union%Square %has%special%historical%status%within%the%District%as% part%of%one%of%the%seventeen%original% federal%appropriations%purchased%by%the%government%in%1792,%and%it%is%described%by%location%and% function%in%a%note%accompanying%Andrew%Ellicott’s%engraving%of%Peter%(Pierre)%Charles%L’Enfant’s%Plan%of% the%City%Intended%for%the%Permanent%Seat%of%the%Government%of%t[he]%United%States Identified%by%L’Enfant% as%a%site%for%an%allegorical%sculptural%group%and water%feature,%the%land%now%occupied%by%Union%Square% was%originally%improved%as%grounds%for%a%national%Botanic%Garden.%Later,%in%the%twentieth%century,%it%was% transformed%into%a%public%park%dedicated%to%the%commemoration%of%the%Civil%War.%The%area% is%bounded% by%two%significant%diagonal%avenues% –%Pennsylvania%Avenue%an d%Maryland%Avenue%–%integral%components of%the%L’Enfant%plan%that%provide%important%views%between%prominent%sites%within%the%city .%Today,%as%a% focal%point%of%the%National%Mall,%Union%Square%serves%as% a%gathering%place%for%celebrations%of%our% national%identity%and%commemorations%of%important%events.

The%L’Enfant%plan%is%significant%as%the%singular%America n%example%of%an%urban%core%that,%from%its% inception,%has%physically%expressed%its %political%role%as%a%designed%national%capital%using%Baroque%design% principles.%L’Enfant%studied%the%natural%contours%of%the%land%to%develop%a%plan%in%which%the%“Grand% squares%or%Areas”%would%be%positioned%at%major%topographic%points%within%the%city%on%“th e%most% advantageous%ground,%commanding%the%most%extensive%prospects.”%L’Enfant%also%created%intentional% “reciprocity%of%site”%within%the%plan,%establishing%vistas%along%radiating%avenues%that%allowed%for%oblique% views%between%major%buildings%and%various%monuments%and%parks.%

At%the%eastern%terminus%of%the%Mall%where%Pennsylvania%Aven ue%and%Maryland%Avenue%converged%with% the%western%edge%of%the%Capitol%Grounds,%L’Enfant set%aside%a%large%open%space%for% an%allegorical% sculpture%group%and%grand%cascade.%This%w ater%feature%flowed%west%into%a%basin%in%the%canal,%which ,%as% planned,%would%turn south%along%3rd%Street%West%in%front%of%the%Capitol.%The%open%spaces%in%L’Enfant’s% plan%were%as%integral%to%the%design%of%the%Capital%as%the%buildings%to%be%erected%around%them.%At%this%site,% L’Enfant provided%a%transitional%element%between%the%flat%broad%expanse%of%the%Mall%promenade%and%the% rising%slope%of%the%Capitol%Grounds

Forming%the%northern%border%of%Union%Square,%Pennsylvania%Avenue%was%the%most%prominent%boulevard% of%the%L’Enfant%plan.%It%provided%a%direct%physical%link%between%the%Capitol%and%the%White%House%and made%a%symbolic%connection%between%the% legislative%and%executive%branches%of%the%Federal%government.% A%historic%civic%space%since%the% eighteenth%century,%Pennsylvania%Avenue%has%been%the%site%of%numerous% monumental%events%of%national%importance%–%Presidential%inaugural%parades,%state%funeral%processions,% protests,%and%marches,%among%others. Maryland%Avenue,%forming%the%southern%border%of%Union%Square,% also offered%a%clear%vista%to%the%Capitol%dome.%It%was%one%of%the%oldest%developed%avenues%in%the%city. The%radiating%vistas%along%Pennsylvania%and%Maryland%Avenue s%were%significant%aspects%of%the%L’Enfant% design.

The%landscape%elements%L’Enfant %planned%for%the%eastern%terminus%of%the%Mall%were%never%realized.% Instead,%in%1820,%Congress%granted%the%Columbian%Institute%for%the%Promotion%of%Arts%and%Sciences,% founded%in%1816,%five%acres%of%land%bounded%by%1 st Street%West,%3rd%Street%West,%Pennsylvania%Avenue,%

NW,%and%Maryland%Avenue,%SW,%to%establish%a%national%Botanic%G arden.%The%nineteenth%century% experienced%a%flourishing%of%botanical%studies%as%global%exploration%encouraged the%discovery%of%new% plant%species%and%expanded%collections.%The%perceived%value%of%the%Botanic%Garden%as%a%center%for% scientific%pursuits%was% expressed%by%its%prominent%location%adjacent%to%the%Capitol At%a%time%when%the% National%Capital possessed%little%in%terms%of%infrastructure,%improvements%to%the%Botanic%Garden% grounds%were%immediate –%the%area%was%graded%and%fenced,%gravel%paths%were%laid%out ,%ponds%were% excavated,%and%trees%were%planted.%A%greenhouse%was%constructed%in%1850%and%enlarged%in%1867.%The% Washington%City%Canal,%which%ran%through%the%Botanic%Garden%site,%was%channeled%into %a%sewer%in%the% early%1870s.%By%the%turn%of%the%century,%the%Botanic%G arden%was%surrounded%by%lush%grounds%and%mature% memorial%trees,%chosen%by%or%planted%in%the%memory%of%prominent%men.%

In%1901,%under%the%Senate%Park%Commission,%a%new%plan%was%drawn%up%that%would%guide%Washington’s% development%for%decades%and%fundamentally%transform%the%monumental%core.%The%McMillan%Plan,%as%it% came%to%be%known,%magnified%and%expanded%L’Enfant’s%plan%for%the%National%Mall,%established%design% standards%for%the%area,%and%ex tended%the%city’s%park%system.%It%is%recognized%today%as% the%primary% American%example%of%the%City%Beautiful%movement %and%a%nationally%significant%model%of%city%planning.%

One%aspect%of%the%McMillan%plan%was%to%open%up%the%Mall%between%the%Washington%Monument%and%the% Capitol,%strengthening%the%central%axis%and%the%primary%east west%vista.%The%Mall%was%widened%to%1600% feet%and%transformed%into%a%broad%lawn%bordered%by%pedestrian%and%carriage%paths%and%framed%by%rows% of%elm%trees,%which%had%the%effect%of%creating%visual%walls.%At%the%Mall’s%eastern%end,%the%McMillan%Plan% eliminated%the%Botanic%Garden%and%replaced%it%with%a%memorial%plaza%symbolizing%the%strength%of%the% Union%and%commemorating%the%Civil%War.% The%plaza%featured%a%formal,%symmetrical%landscape%design,%a% central%fountain,%and%three%statues%of%generals%that%faced %west%toward the%planned%memorial%to%Lincoln. West%of%the%plaza%(outside%the%current%boundaries%of%Union%Square),%the%design%called%for%a%reflecting% pool%along%the%Mall’s%central%axis%between%3rd%and%4%½%Streets%West.%The%McMillan%Plan%realigned% Pennsylvania%and%Maryland %Avenues%to%run%directly%east west%from%3rd%Street%West%to%the%Capitol% Grounds

The%Grant%Memorial%at%Union%Square%was%dedicated%in%1922 %as%a%thematic%complement%to%the%Lincoln% Memorial%and%a%symbol%of%the%preservation%of%the%Union.%One%of%the%largest%and%most%complex% sculptures%in%Washington,%the%memorial%consists%of%a% large%marble%platform%with%a%central%equestrian% statue%of%Grant,%four%bronze%lions,%low%relief%panels,%and%flanking%sculptural%groups%of%milit ary%figures.% Five%years%after%the%Grant%Memorial%was%dedicated,%a%second%Civil%War%monument%–%the%Meade% Memorial%–%was%erected%in%Union%Square.%The%symbolic%theme%of%Union%Square%was%the%only%aspect%of% the%McMillan%Plan to%be%fulfilled %for%the%site.

In%1934,%Frederick%Law%Olmsted,%Jr.,%was%retained%to%redesign%Union%Square.%His%plan%treated%the%site%as%a% transitional%area%between%the%Mall%and%the%Capitol%Grounds%and%maintained%the%site’ s%symbolic%function% as%a%memorial%to%the%Union.%Olmsted’s%plan%retained%the%historic%alignment%of%Pennsylvania%and% Maryland%Avenues,%removed%trees%to%create%a%central%open%space%and%reinforce%the%east west%axis%of%the% Mall%and%the%primary%vista%from%the%Capitol,%reintroduced%2 nd%Street%West%through%the%site,%maintained%

Robinson%&%Associates

the%curved%boundary%of%the%Capitol%Grounds,%and%place d%memorial%statues%in%the%landscape%panels% created%by%2nd%Street%West%and%3rd%Street%West. Olmstead’s%plan%did%not%include%any%pools%or%wa ter% features.%Planting%beds%were%arranged%symmetrically%around%the%Grant%Memorial. Trees%located%in%the% panels%to%the%north%and%south%of%the%central%open%space%and%clustered%around%the%Grant%Memorial% formed%visual%links%between%the%regularly%spaced%trees%along%the%Mall%and%the%trees%growing%on%the%west% grounds%of%the%Capitol.%Although%there%was%considerable%public%opposition%to%the%removal%of%trees%from% the%Botanic%Garden%site,%Olmsted’s%transplanted%as%many%memorial%trees%as%possible.%To%implement%the% Olmsted%plan,%the%gardens,%conservatory,%greenhouses,%paths,%and%other%elements%of%the%Botanic%Garden% were%cleared%or%relocated.%Olmstead’s%plan%integrated%the% adjacent%Peace%Monument%and%Garfield% Memorial%(dedicated%in%1877%and%1887,%respectively) into%the%design%of%Union%Square,%using%them%to% demarcate%the%northeast%and%southeast%corners%of%the%site.%

Union%Square%as%it%exists%today%was% im plemented%between%1969%and%1971%following%a%plan%by%Skidmore,% Owings%&%Merrill%(SOM)%with%landscape%consultant%Dan %Kiley.%The%design%was%part%of%a%master%plan% developed%by%SOM%for%the%entire%Mall%and%was%driven%in%part%by%the%construction%of%Inner%Loop%Freeway% underneath%the%site A%large,%slightly%curved%reflecting%pool%surrounded%by%a%sunken%walk%is%the% centerpiece of%the%design.%Its%introduction%revived%the%McMillan%Plan%concept%for%a%reflecting%pool%at%the% east%end%of%the%Mall.%W est%of%the%pool%is%a%broad%plaza;%isolated%groups%of%trees,%some%dating%from%the% Botanic%Gardens,%are%located%in%informal%massings%at%the% corners%of%the%site.%The%Grant%Memorial%and%its% marble%base%and%granite%and%concrete%plaza%were%integrated%into%the%SOM%design Implementation%of% the%SOM%plan%required%the%elimination%of%Olmstead%plan%design%features%and%circulation%routes,% the% relocation%of%the%Meade%Memorial,%and%the%removal%of%dozens%of%trees.%

Union%Square%is%listed%in%the%National%Register%of%Historic%Places%as%part%of%the%National%Mall%and%as%a% contributing%element%of%the%Plan%of%the%City%of%Washington.%%

Design%Analysis

This%Union%Square%design%concept%carries%forward%the%most%critical%historical%concepts%inherent%to%the% site’s%evolution :%it%retains%the%site’s%symbolic%function%as%a%memorial%to%the%Union;%it%reinforces%the%east west%axis%of%the%Mall;%it%treats%Union%Square%as%a%transitional%area%between%the%Mall%and%the%Capitol% Grounds;%it%forms%visual%links%between%the%adjacent%historic%landscapes;%and%it%frames%and%defines%the% historic%vista%from%the%Capitol%to%the%Lincoln%Memorial%and%the%western%horizon.%

Recognizing%the%site’s%prominence%as%the%eastern%terminus%of%the%Mall%and%the%forecourt%to%the%Capitol,% this%design%concept%for%Union%Square%interprets%and%extends%the%vision%of%L’Enfant%and%successive% historic%plans.%

• The%design%concept%reestablishes%the%site’s%historic%function%as%a%transitional%space%between%the M all%and%the%Capitol%Grounds.%A%rectilinear%reflecting%pool,%fitting%the%Mall% geometry%and%setting,% will%extend%the%spatial%configuration%of%the%central%grass%panels%of%the%Mall.%Circulation%patterns% will%follow%the%Mall’s%primary%east west%axis%and%form%a%visual%connection%to%the%Capitol% Grounds.%The%placement%of%trees%in%massings%north%and%south%of%the%Grant%Memorial%and%in%

Robinson%&%Associates

panels%along%the%south%edge%of%the%reflecting%pool%will%provide%a%transitional%element%between the%rectilinear%grass%panels%of%the%Mall’s%central%landscape%and%the%picturesque%massings%of%trees% on%the%west%lawn%of%the%Capitol.

• The%design%treats%the%Grant%Memorial%as%a%focal%point.%The%Memorial%will%remain%in%its%current% position%demarcating%the%east%end%of%the%Mall%and%overlooking%the%grand%vista%to%the%Lincoln% Memorial.%The%site’s%relation%to%the%Capitol%will%be%strengthened%by%extending%the%steps%of%the% Grant%M emorial%to%the%east,%creating%a%“platform”%or%“stage”%to%encourage%participation%with%the% west%lawn%of%the%Capitol%Grounds

• The%design%respects%the%McMillan%Plan%vision%for%the%Mall%by%locating%a%new%reflecting%pool%at% the%east%end%of%the%Mall%as%a%counterpoint%to%the%Lincoln%Memorial%Re flecting%Pool%to%the%west Its%form%and%placement%strengthens%the%conceptual%symmetry%of%the%Mall’s%east west%axis.

• The%design%recognizes%Pennsylvania%Avenue% –%the%“Avenue%of%the%Presidents”%–%as%a%National% Historic%Site%and%national%ceremonial%route%by%eliminating%the%street%parking%that%currently% detracts%from%the%avenue’s%significance.%Although%the%final%block%of%Pennsylvania%Avenue%closest% to%the%Capitol%will%be%repaved%and%transformed%into%a%pedestrian%promenade,%historic%aspects% such%as%the%street%wid th,%lighting,%and%trees%will%be%maintained.%

• The%design%treats%Maryland%Avenue%as%a%significant%radiating%avenue%of%the %L’Enfant%plan%by% eliminating%street%parking,%allowing%the%historic%continuity%of%the%avenue%to%be%read%more%clearly.% Although%the%segme nt%of%the%roadway%adjacent%to%Union%Square%will%be%decreased%in%width%to% allow%for%additional%sidewalk%and%street%trees,%the%design%retains%the%avenue’s%historic% alignment.

• The%design%draws%on%the%contextual%landscape%to%incorporate%tree%massings%in%a%man ner%that% frames%historic%axial%vistas%from%the%Grant%Memorial%and%the%Capitol%and%radiating%vistas%along% Pennsylvania%and%Maryland%Avenues%–%significant%aspects%of%the%L’Enfant%design. Historic%trees%at% the%northwest%and%southwest%corners%of%the%site,%some%dating%from%the%Botanic%Garden% plantings,%will%be%retained.%

• The%design%recog nizes%the%historic%alignment%of%2nd Street%West%by%integrating%pedestrian%paths through%the%site%on%either%side%of%the%reflecting%pool

• The%design%moves%the%Peace%Monument%and%Garfield%Memorial%into%the%“pedestrian%realm”%of% Pennsylvania%and%Maryland%Avenues,%altering%the%Olmsted%plan%for%the%Capitol%Grounds.%

WASHINGTON NATIONAL MALL COMPETITION

Space Syntax Text

SPATIAL PLANNING APPROACH

The Washington National Mall initiative demonstrates the high levels of aspiration the city and its key stake holders have for the nation’s most prestigious series of open spaces. The spatial changes involved have the potential to create significant improvements to the area, and in the context of a wider public realm strategy. The National Mall is currently facing a number of challenges in ter ms of the sustainable development of its’ public realm. The pedestrian movement activity patterns are mostly attractor driven (tourist attractions, including monuments, government and cultural institutions, transport interchanges) and function largely separately from the pedestrian dynamics generated by the spatial network of the city centre of Washington. Secondly, th e National Mall has to both function well for large crowds during major events, as well as on a day to day basis, when it is much less busy a nd has the potential to become a more attractive resource for local residents, workers, as well as all for all other casual visitors. However, currently The National Mall is struggling to provide a first class visitor destination and experience.

A clear understanding of the spatial mechanisms, significantly driving pedestrian movement patterns in the centre is key to fully understand the potentials and the impact of the National Mall Projects. In fact, this is an opportunity for the city to cast a holistic view of the city centre and on this basis develop interventions in synergy with all other proposals for the wider area. The transport strategy for Washington promotes walking and cycling and an inclusive and accessible approach to transportation. Combined with reprioritisation of network capacity and safety measures this will support a thriving public realm and high degrees of social inclusion.

We have used pioneering spatial accessibility modelling techniques to evaluate the existing network of pedestrian routes and public spaces in Washington’s City Centre. Combined with a systematic evaluation of the attractors, including public transport infrastructure and cultural and tourist destinations, this exercise enables the wider team to make informed and holistic public realm design decisions.

THE IMPORTANCE OF A ROBUST SPATIAL NETWORK FOR THRIVING CITY CENTRES

City Centres are foremost places of social, cultural and economic transactions between people. They function at their best when they are made up of a legible route network with a fine urban grain, distributing movement conveniently into the surrounding context and creating a clear hierarchy of continuous, busy main roads with key attractors and more quiet side streets attached to them. Such highly walkable structures overlap city-wide accessibility with good access from a strong local catchment area in order to support the urban economy and sustain good levels of footfall throughout the day and week. A good city centre supports a network of interlinked open and green spaces connected by streets lined with active frontages. The approach to the needs of pedestrians, cyclists, vehicular traffic and buses needs to be balanced and take into account the naturally emerging hierarchy of the route network.

PRINCIPLES OF WELL WORKING PUBLIC OPEN A ND GREEN SPACES

Extensive research by Space Syntax and University College London into the design and functioning of urban areas shows consistently that there are a number of key conditions making public open and green spaces successful. Successful spaces are located at strategic points in the pedestrian movement network i.e. the intersections of important pedestrian movement routes.To achieve good levels of use, it is important that the routes bring movement from several directions through the heart of the space, not just ‘skirt’ around the edges. People are more likely to use spaces where they can see where they are going and see other people animating the space . Similarly people prefer to stay where they have good visibility from within a space into the surrounding area.Good seating, lighting, high-quality landscaping all encourage informal/stationary activity within public spaces. Live uses, such as cultural, retail and catering uses attract activity over and above the effects of spatial layout and contribute to the natural surveillance of the space by providing presence in the space.

PROPOSED SPATIAL STRATEGY FOR THE NATIONAL MALL

Spatially speaking, the National Mall today works largely as an attractor, rather than as a natural focus for everyday city movement. The opportunity therefore exists to do both. The National Mall is strongly orientated east-west and therefore the opportunity should be firstly to enhance the internal spatial logic of the already strong east-west axis with an improved north-south orientation. Secondly, the strategy should be to enhance edge-to-centre connections by improving peripheral spatial connections and the interface with the city context Together, these two strategies create an enhanced National Mall. Locally distinct. Globally connected.

THE SPATIAL ACCESSIBILITY MODEL

Independent research has consistently shown that spatial configuration as measured by spatial accessibility is one of the key factors that influence movement in urban areas. Spatial accessibility maps frequently provide a robust forecast of actual patterns of movement, with the distribution pattern of movement closely following the distribution of accessibility values. We call the amount of movement that can be accounted for by spatial configuration the ‘natural movement’ of an area. The strategic spatial accessibility maps illustrate the degree of movement potential within approximately 25 minutes walking distances. The warmer the colour of the street segment is, the more likelyit is that people will take that route on their journeys to and from all destinations

26.03.2012

UNION SQUARE

UNION SQUARE

Union Square is located at the eastern end of The National Mall and in front of the State Capitol Building. On the city level, it is located at a strategic point in the pedestrian movement network at the junction of Pennsylvania Avenue, Maryland Avenue, Constitution Avenue, Independence Avenue, First Street, Third Street and at the end of Louisiana Avenue which connects it to Union Station. However, Union Square itself currently does not fully exploit this potential. Movement is largely directed around the edges of the space, with very little activity within the heart of the space or convenient connections across, which would embed the space and this end of The National Mall more firmly within the wider pedestrian movement network

The design proposal extends the exiting east west routes of the National Mall straight into the heart of the Space. Combined with improved crossing points this will enhance the connection between The National Mall and the space. Once in Union Square a series of convenient new diagonal routes and connect visitors with strategic points in the pedestrian movement network, such as the roundabouts at the ends of Pennsylvania, Maryland and Louisiana Avenues. A new north-south link is introduced along the alignment of Second Street connecting the site better locally and with the US Botanical Gardens. Within this network of routes a number of new spaces to rest and enjoy the Square and its significant views are created, around the basins, and at the basin of the Grant Memorial. These locations will at the same time be excellent spots for watching other people, one of the main activities in public spaces. Such stationary activity will contribute to the attraction of this space, which will increase significantly as a result of the redesign.

The combined impact of the proposed spatial interventions will have a significant impact on pedestrian activity potentials within the space itself as well as on the eastern part of The National Mall.

March!28,!2012

Union$Square –$Transportation$Narrative

Union!Square!is!located!west!of!the!US!Capitol!Building!in!the!parcels!bound!by! Constitution Avenue!NW,!Independence! Avenue!SW,!3rd!Street!NW/SW!and!First!Street!NW/SW.!!Regional!access!to!the!site!will!primarily!arrive!on!either! Independence!Avenue!or!Constitution!Avenue!depending!on!the!direction!of!approach.!!Interchange!ramps!for!I 395, offering!nearby!freeway!access,!are!located!south!of!the!site!at!Washington!Avenue!SW!and!2nd!Street!SW.!

Constitution!Avenue!is!part!of!the!Federal!Highway! System!and!carries!the!designation!of!US!Route!1.!!Constitution!Avenue! along!with!Independence!Avenue,!3rd!Street!and!Pennsylvania!Avenue! (west!of!3rd!Street)!are! classified!as!Principal!Arterial! streets!by! the! District!Department!of!Transportation!Roadway!Functional!Classification!Map.!!Consistent!with!their! classification,!all!of!these!streets!carry!significant!traffic!volumes!and!make!vital!links!in!the!transportation!network.!! Constitution!Avenue!carries!35,400!daily!trips!and!Independence!Avenue!processes!36,000!daily!trips!according!to!DDOT! data.!!Third!Street!carries!relatively!fewer!daily!trips!at!13,100.

Pennsylvania!Avenue!comes!into!the!site!terminating!at!the!intersection!of!First!Street!NW!known!as!Pea ce!Circle.!!This! section!of!Pennsylvania!Ave!is!classified!as!a! Collector!street,!but!primarily!serves!as!permit!parking!for!the!Capitol!Complex and!serves!no!function!for!through!traffic!in!the!local!network.!!This!section!of!Pennsylvania!Avenue!is!in!contrast!to!the!rest! of!the!corridor!which!exists!as!a!boulevard!symbolizing!the!connection!between!the!White!House!and!the!US!Capitol.!! It! should!also!be!mentioned!that!Pennsylvania!Avenue!has!a!dedicated!two way!bicycle!track!located!in!the!median!west!of! 3rd!Street,!but!the!cycle!track!does!not!presently!extend!into!the!site.

Maryland!Avenue!SW!on!the!southern!portion!of!the!site!mirrors!Pennsylvania!Avenue!and!similarly!functions!as!local! access!and!permit!parking!for!Capitol!Complex!staff.!! Maryland!Avenue!is!designated!as!a!Local!street!by!DDOT.!! Maryland! Avenue!also!terminates!in!the!site!at!First!Street!at!the!intersection!with!Garfield!Circle.! However,!unlike!Pennsylvania! Avenue,!Maryland!Avenue!has!little!role!in!the!transportation!network!moving!westward!away!from!the!site.!!Maryland! Avenue!has!a!disjointed!alignment!that!will!be!further! degraded!with!the!construction!of!the! Dwight!D.!Eisenhower Memorial!between!4th!and!6th!Streets!SW,!and!therefore!it!primarily!serves!local!traffic!only.

First!Street!and!3rd!Street are!the!only!alignments!to! make! a!complete!north south!connection!across!the!site.!!Due!to! security!concerns,!the! First!Street! alignment!over!time!has!been!diminished!by!closing!the!section!south!of!Independence! Avenue!to!through!traffic!and!making!the!section!south!of!Garfield!Circle!one way!northbound!such!that!it!only!serves!local! traffic.!!The!presence!of!the!Capitol!Complex,!associated!street!closures!for!security!and!the!I 395/SW SE!Freeway! alignment!create!barriers!and!limit!north south!circulation !opportunities!in!this! area!of!the! City.!!This!places!importance!on! 3rd!Street!as!a!needed!connection!across!the!National!Mall!in!the!larger!transportation!network.

There!is!no! public! parking!on!the!site!and!there!is!not!any! public! parking!proposed!in!the!plan.!! Visitors!to! Union!Square arriving!by!car!must!rely!on!metered! street!parking!which!is!available!on! 3rd!Street!and!many!of!the!streets!to!the!west.!! Most!of!the!parking!is!limited!to!two!hours!and!portions!are!subject!to!morning!and!evening!peak!periods! restrictions.!! Given! the! importance! of!the!surrounding!arterial!streets! in!the!transportation!network,!peak!period!towing! on!streets!with! restrictions!is!strictly!enforced.!!There!is!very!limited!off!street!public!parking!in!the!vicinity! of!the!site.

Visitors!to!the!National!Mall!are!encouraged!to!utilize!public!transportation!given!the!limited! availability!of!parking!and!as!a! transportation!demand!management!measure!to!reduce!the!traffic!demand!on!the!network.!!The!nearest!Metrorail!stat ion!

offering!Blue!and!Orange!line!service!is!the! Federal!Center! Station!located! with!a!portal!at!3 rd!and!D!Streets!SW .!!The! Federal!Center!station!is!a! 5! minute!walk!to!the! south!of!the!site.!! Alternatively,!the!Judiciary!Square!Metrorail!Station!with! Red! line!service!is!a!10!minute!walk!to!the!north!at! 4th!and!D!Streets!NW. Metrobus!service! is!available!nearby!with!ro utes! offering!service!connecting!to!Metrorail!stations!and!other!destinations!in!all!directions

Capital!Bikeshare!is!a!growing!mode!of!transportation!in!the!District.!!There!is!a!station!located!a!couple!blocks!from !the!site! at!the!corner!of! Maryland!and!Independence!Avenue.!!Members!can!pick!up!a!bike!at!any!of!the!140!stations!located!in!the! District!and!Arlington,!Virginia,!and!return!th em!at!any!station.!!Daily!passes!are!also!available!at!each!station!for!infrequent! users!or!those!visiting!from!out!of!town.!!Several!new!stations!recently!opened!on!and!near!the!National!Mall!with!other! additional!stations!planned!as!demand!increases

The!site!is!part!of!the!Capitol!Complex!and!as!such!is!subject!to!the! security!restriction s!imposed!by!the!Capitol!Hill!Police.!! All!of!the!streets! immediately! surrounding!and!within!the!site!are!open!to!public!traffic !with!the!exception!of!Southwest! Drive!and!Northwest!Drive!which!encircle!the!Capitol!Building.!!However,!truck!traffic!is!restricted!from!using!Constitution! and!Independence!Avenues.!!Any!trucks! or!service!vehicles! seeking!to!enter!the!Capitol!Complex!must!follow!the!security! protocol!which!requires!off!site!screening!and!clearance.

One!function!that!takes!place!along!First!Street!and!at!Garfield!and!Peace!Circles!is!charter!bus!pick!up!and!drop!off.!!Like! trucks,!motorcoaches!are! prohibited!from!using!Constitution!or!Independence!Avenues,!or!Fi rst!Street!NE/SE!in!front!of!the! Capitol!Visitors!Center!due!to!security!concerns ,!although!buses!do!not!need!to!have!a!security!prescreen M otorcoaches! are!instructed!to! use!First!Street!and! both!traffic!circles! on!the!Capitol!Building’s!western!front! to!disembark!passengers.!! The!proposed!plan!for!Union!Square!would!relocate!this!activity!to!designated!portions!of!3rd!Street.!!

A!major! objective!of!the!proposed!plan!for!Union!Square!is!to reduce!the!presence!of!vehicular!traffic!on!the!site!and! improve!the!environment!for!pedestrians!and!bicyclists.!!The!transportation!infrastructure!internal!to!the!Union!Square!site today!represents!an!auto oriented!character!which!detracts!from!the!importance!of!the!space!adjacent!to!US!Capitol.!! Along!with!relocating!the!charter!bus!activity!to!3rd!Street,!the!proposal!would!remove!the!permit! parking! that!presently! exists!on!Pennsylvania!and!Maryland!Avenues.

As!discussed!previously,!3rd!Street!serves!an!important!role!in!the!overall!connectivity!of!the!transportation!network!of!the! City.!!However,!it!also!creates!an!unintentional!“barrier”!in!connecting!Union!Square!to!the!rest!of!the!National!Mall! beyond.!!To!minimize!this!separation!and!improve!the!character!of!the!3rd!Street!crossing!for!pedestrians!and!cyclists,!th e! proposal!would!reduce!the!street!cross section.!!Presently!3 rd!Street!consists!of!a!76’!section!curb!to!curb!which!very! generously!accommodates!four!travel!lanes!(two!northbound!and!two!southbound)!and!a!parking!lane!in! each!direction.!!By! present!design!standards,!this!cross section!could!be!reduced!significantly!without!reducing!any!roadway!capacity.!!The! proposed!plan!will!take!this!excess!pavement!out!of!3rd!Street!narrowing!the!street!section.!!This!will!shorten!the!crossing! distance!for!pedestrians! and!cyclists,!slow!vehicular!travel!speeds!for!a!safer!condition,! and!improve!signal!operation!as!less! time!will!be!required!for!pedestrians!to!cross!the!street.

An!important!aspect!to!the!sustainability!of!the!site!is!reducing!the!energy!and!carbon!footprint.!The!strategy!for! energy!reduction!has!been!developed!to!firstly!reduce!onsite!energy!usage!through!efficiency!measures!and! intelligent!controls.!Once!site!energy!intensity!is!decreased!implementation!of!renewable!and!clean!energy! technologies!will!be!used!to!offset!the!remainder.

The!conservation!strategy!first!starts!with!an!assessment!of!site!energy!users.

• Site!Lighting

• Walkway!Lighting

• Water!Feature!Circulation!Pumps

• Pool!Drainage!Pumps

A!summary!of!the!annual!energy!consumption!is!shown!below:

Walkway Lighting

Site Lighting

Drainage Pumps

Water Feature Pumps

The!majority!of!the!site!energy!savings!comes!from!lighting!energy!reductions!and!high!efficiency!pumps !By! switching!from!typical!metal!halide!lamps!to!a!LED!lamps!and!electronic!ballasts!energy!usage!can!be!reduced!by! nearly!50%.!This!savings!comes!from!more!efficient!lamps!and!enhanced!controls!which!allows!lighting!to!provide! only!the!required!amount!of!illumination!a!certain!times!during!the!day.!!

The!next!step!is!to!offset!the!remainder!of!the!energy!usage.!We!first!investigated!the!use!of!conventional!renewable! energy!technologies!such!as!solar!and!wind.!We!found!that!it!would!not!be!feasible!to!offset!all!of!the!energy!usage! with!these!systems.!It!would!require!a!footprint!of:

Solar!PV!–!12,600!ft2

Small!Scale!Wind!Power!–!105!Turbines

This!document!may!contain!confidential!and!legally!privileged!information!and!must!be!used!only!for!its!intended!purpose.!!Any!unauthorized!copying,!dissemination!or!use!in!any!form!or!by!any! means!other!than!by!the!addressee,!is!strictly!prohibited.!If!you!have!received!this!document!in!error!or!by!any!means!other!than!as!authorized!addressee,!please!notify!us!immediately!and!we! will!arrange!for!its!return!to!us.

A!much!more!reasonable!clean!energy!technology!would!be!to!install!a!fuel!cell!system!sized!for!approximately!100! kW.!These!systems!are!low!maintenance!and!produce!electricity!with!very!little!environmental!impact.!The!unit! would!be!connect!to!a!natural!gas!fuel!source!but!do!not!use!combustion!to!produce!energy!instead!they!rely!on!a! chemical!process.!Many!of!these!systems!also!include!an!annual!maintenance!contract.!One!of!the!by!products!from! the!electricity!generation!is!heat!which!could!potentially!be!used!for!a!nearby!building.!

Because!these!systems!are!inconspicuous,!w e!would!also!like!to!include!a!more!visible!clean!energy!system.!The! systems!under!consideration!are!as!follows:

• Micro&Wind&Turbines:!These!wind!turbines!are!much!smaller!than!the!conventional!scale!turbines!and! start!to!turn!generating!electricity!a!much!lower!wind!speeds.!An!interesting!location!that!has!a!very! consistent!wind!source!is!the!395!tunnel!adjacent!to!the!site.!It!could!be!possible!to!generate!up!to!5%!of!the! site!energy!demand.

• Solar&PV&Paving&systems :!These!systems!are!currently!under!development!by!several!different! manufactures.!Although!not!commercially!available!at!the!current!time!indicators!are!showing!that!they!may! be!in!the!market!in!the!very!near!future.!It!could!be!possible!to!generate!up!to!a! 4%!percent!of!the!site! energy!demand!for!every!1,000!ft2!installed.!Prime!locations!would!be!bike!paths!enter!the!site!and! crosswalks.

• Piezoelectric&pads:!These!pads!have!the!ability!to!create!electricity!from!people’s!footsteps.!It!is!an! emerging!technology!but!there!are!showcase!uses!in!Japan!train!stations!and!eco nightclubs.!It!is!estimated! based!on!the!annual!number!of!site!visitors!that!!7% 12%!of!site!energy!could!be!offset!depending!on! location!and!usage.

Water Feature Design Narrative

Union Square – Washington DC

CMS Collaborative Fountain Consultant

General

This group of water features at the National Mall shall occupy the area in front of the Ulysses S. Grant Memorial, largely circumscribed by Pennsylvania Avenue Northwest, Maryland Avenue Southwest, and Third streets Northwest and Southwest. These displays will in aggregate replace the old Capital Reflecting Pool. The goal shall be to produce a modernized, more sustainable water program one which recreates the grandeur and scaled magnitude of the old reflecting pool while also allowing large, discrete areas of display water to be drained and stored singly or in groups thereby opening up previously unavailable Mall geography to public events. Stored water resulting from drainage shall be re-used, so no water is wasted in the process.

Description of Water Features

The water features shall be oriented along two perpendicular axes. When all water feature elements are operating (none drained to reclaim usable space), the larger group of pools shall form a rectangle oriented on-axis with the national mall, beginning near Third Street, and terminating at the front of the Grant Memorial.

Four shorter, narrower rectangular elements shall also be oriented al ong a North-South axis, beginning with a basin placed north of Pennsylvania Avenue NW and ending with a stepped cascade which approaches Maryland Avenue SW. This group of rectangular features intersects the larger East-West rectangle discussed above near the front of the Grant Memorial: Three of the features two basins and a stepped cascade--are to the north of the large r (rectangular) group of pools, while a fourth stepped cascade is south of the larger group.

Large Rectangular Feature Group

This group of planer water displays consists in aggregate of six distinct pools, separated by diagonal and axial walking paths. Viewed in plan the group as a whole forms a large rectangle, whose long axis stretches from near the front of the Grant Memorial to Third Street. The pools are to be of two types:

1) shallow reflecting pools (1 to 2 -inch depth) with gradually sloped edges, and 2) similarly shallow pools with sloped edges, but which also contain patterned layouts of flush -in-floor water jets. There shall be three pools of each type (total of six pools); four shall be largely triangular, and two shall be rectangular.

In all cases, water is discharged into the pools through floor fittings, water jets, or some combination of the two. Water then flows into grade -level slots surrounding each pool, and then into a large hidden storage reservoir, thus completing the hydraulic circuit. Regarding the jet pools, a small ultra -sonic wind speed sensor/transmitter will monitor wind velocity and direction, and report back to th e microprocessor (PLC) based fountain control system. The system shall be configured and programmed such that water jets in the three jet pools are automatically lowered or shut down in moderate or high wind conditions, thereby militating against overspray

As discussed above, an important feature of this design is that it allows some or all of the six pools to be selectively drained so that the space can be used for event staging. The un -drained pools would operate normally. Small or large events will be a ccommodated, depending on the number of pools being drained to storage. We expect that the command to drain the pool(s) can be issued from within the equipment space, or remotely via BMS or internet based connectivity. Also as previously noted, when the pools are drained, the water will be stored in cisterns or the main display reservoir, so that it can be re-used once the event has concluded.

Smaller Rectangular Display Elements

As noted above, this aspect of the overall program consists of four smaller, n arrower elements, perpendicular to the larger display discussed above. There will be two element types: 1) Basins, of which there are two, and 2) Stepped Cascades, again of which there are two. One of the basins shall be across Pennsylvania NW. The next el ement is also a basin (moving back across Pennsylvania avenue NW). There are then two stepped cascades located on either side of the large rectangular array of pools discussed above . Note that when the stepped cascade displays are shut down, they shall leave no standing water. All cascade water returns to the hidden storage reservoir previously discussed. The basins shall also likely be supplied with filtered and treated water from the hidden reservoir.

Sustainability

The notion of sustainability shall be approached from a number of angles, with the goal being to produce the most sustainable water feature possible. Increased sustainability typically comes from optimization of three factors: 1) energy conservation, 2) water conservation, and 3) minimization of chemical additives.

In order to minimize energy consumption, we will explore the use of fuel cell technology, which can be much more efficient than taking electricity directly from the grid while offering a reduced carbon footprint as well. We shall also use variable speed pump motor drive (VFD) technology which allows the fountain operator to slow the pump so that only the energy required to operate the display is utilized reduced flowrates are produced by slower pump speeds as opposed to the useless bu rning of horsepower across a partially closed throttling valve.

In order to minimize reliance on potable water sources, fountain overflow effluent resulting from rainstorms shall be diverted to a large, separate cistern or group of cisterns. The rain/overflow capture cistern(s) shall then provide the first source of water make-up. Potable water sources shall be utilized only in the event that the rain /overflow cistern source cannot keep up with demand.

A second strategy for water conservation shall be to utilize a fully automated, regenerative DE (diatomaceous earth) type filter to eliminate backwash (cleaning cycle) related discharge of chlorinated water. This filter also has the advantage of providing high filtration flowrates with a relatively small footprint. The net results are 1) the sewer system is not burdened with high backwash rates typical of standard filters, 2) chemicals are therefore not wasted during backwashing, which also lowers environmental impact, and 3) water is conserved due to the la ck of a standard backwash cycle, which would otherwise dump thousands of gallons of water each time the filter backwashes.

Given that the majority of these water features will see some form of human contact, they will likely require chemical treatment similar to that of a public swimming or wading pool. That being said, our design will likely also utilize a non- chemical based ozonator to back-up chlorination and thereby reduce chlorine demand. A carful analysis of local codes shall be conducted to ascertain the chemical as well as filtration requirement to insure public health.

Typical Maintenance Schedule

As Required

Vacuum and/or brush the display according to applicable aesthetic criteria. Brush away any minor infestations of "clinging" algae in lieu of greatly increasing the biocide dosage rates.

Three Times Weekly or as Required

Clear all debris from the water feature which could or has settled over pool fittings or fixtures.

Check all circuit breakers to be sure that none have tripped. If any breakers have in fact tripped, isolate and correct the problem.

Check water pH, hardness, and total dissolved solids (TDS) values for the display. If these are not within the recommended ranges, report this to the water treatment contractor or correct the problem if treatment is being done "in house."

Clean the basket strainers that serve the pumps

Once Monthly or as Required

Test all ground fault interrupter (GFCI) circuit breakers. Proper operation of these GFCI breakers can, in extreme cases, save someone's life! Therefore, proper operation of the units must be maintained. This is a LIFE SAFETY ISSUE.

Depress the TEST ALL ILLUMINATED PILOT DEVICES pushbutton. If any of the illuminated selector switch operators or pilot lights do not illuminate, the lamps should be replaced.

Clean all debris from the equipment space.

Check that the fountain system is not ove rflowing after shut-down. This can be checked (assuming it has not rained during the current operating period) at the drain line sight glass by shutting off the fountain and waiting until all flow over the weirs has ceased. Please refer to chapter Water Level Control as needed.

Inspect the chemical controller as described in this document.

Once Every Two Months or as Required

The water level probe holders should be inspected. Any accumulation of material at or in the connecting pipe between the probe holders and display must be removed so that water can freely enter and exit.

Clean the pilot wye -strainers on the diaphragm type water supply and total dissolved solids (TDS) bleed valves.

Verify the pump low pressure shutdown functions by slowly closing the respective suction isolation valves. The pumps should shut down at approximately the following pressures:

Shut-down pressures:

Display pumps: 2 psi below normal operating pressure with clean strainer and normal flowrate.

Filter pump: 2 psi below normal operating pressure with clean strainer and normal flowrate.

If problems are encountered, or the values have not been entered, follow the applicable procedures and provisions specified in chapter Pumping System .

Every Three Months

The water level probes should be cleaned with light emery cloth to remove any scum, scale, or rust which would tend to form an insulating layer and lower their conductivity.

The probe holder can be removed by lifting the holder and PVC coupling from the riser (the coupling should not be glued to the pipe). Take care that the vent hole in the coupling is realigned with the hole in the riser.

Any corrosion damaged probes should be replaced if the damage is severe enough to impede proper function. The chapter on water mainten ance should be consulted, and steps should be taken to mitigate against future corrosion.

Check the settings of the pump and biocide time switch circuits.

Miscellaneous

Service the pumps, following the maintenance instructions in the Product Literature Binders supplied by the mechanical and electrical contractors.

Chemical Water Treatment

All procedures are to be performed according to the relevant provisions and guidelines specified by manufacturers.