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President Trump has promised to drain the swamp in Washington. We ran this through Autocase for Green Infrastructure to see what the value is of this “strategy”. We centered the project at 1600 Pennsylvania Avenue (although we considered running it from Trump’s hotel at 1100 Pennsylvania Ave). But, using the White House as the project site, we find an interesting result - that the Trump International Hotel may be the biggest beneficiary from the natural ecosystem.

The project was set to run for 4 years starting on January 20th 2017. We assumed a 100-day (de-) construction period. We left the planning period at zero since that is not the President’s strong suit.

We ran Autocase for Green Infrastructure to value an existing 1-acre swamp in D.C. to see what we’d lose from draining it.

Green infrastructure such as a swamp has many benefits; stormwater is naturally cleaned of pollutants, flooding is reduced, air pollution and carbon emissions are reduced, urban heat island effects are reduced, and property values are enhanced.

The swamp creates positive social and environmental value for Washington and also have value on a national or global scale.

In Autocase for Green Infrastructure, the value of a project is summarized in terms of Financial or Sustainable Net Present Value, or NPV. The Financial NPV only includes costs and benefits that involve cash flows to the government. Since this is an existing swamp there are no capital expenditures or operations and maintenance (O&M) costs but there are avoided costs (without the swamp you need additional piping and detention to handle the stormwater run-off so Autocase for Green Infrastructure has calculated the capital expenditures and O&M costs for these items).

The Sustainable NPV, on the other hand, includes not only financial cash flows but also the monetized value of all of the project’s social and environmental net benefits to society as a whole. In this case these, to be conservative water quality benefits were not included. Other benefits include changes in carbon emissions (Autocase allows setting the social cost of carbon to zero, or any other value, if President Trump so wishes).

Other benefits include changes in air quality, urban heat island reduction, property value uplift, and a reduction in flooding.

In the case of keeping the 1-acre swamp, the total Sustainable Net Present Value is $137,706. This means that this design alternative has a positive total value when summing together the Financial, Social, and Environmental costs and benefits. Therefore the saving the swamp project has an overall net positive value to society.

Overall, saving the swamp will result in reduced government outlays on piping and detention to stop flooding. It also has a positive social and environmental value and brings overall benefits to the surrounding region including President Trump’s hotel. We think President Trump should re-consider.

John Parker
Chief Economist
Impact Infrastructure



By Scott Grayson, APWA Executive Director, and Jim Horne, EPA Sustainability Program Manager

Since 1960, APWA has sponsored National Public Works Week in the third full week of May. Across North America, APWA’s nearly 30,000 members in the U.S. and Canada use this week to energize and educate the public on the importance of public works to their daily lives. This year’s National Public Works Week theme “Public Works Connects Us” celebrates the vital role public works plays by providing, maintaining, and improving the structures and services – streets, roads, bridges, public transportation, clean water and sanitation services – that keep us connected, productive and healthy and allow our communities to grow and prosper.

This week also presents an opportunity to highlight how public works professionals are leaders in planning, building, managing and operating our critical water infrastructure. A great example of this type of leadership is the collaboration established by APWA, EPA, and nine other major national water sector organizations to develop an important water utility management program: Effective Utility Management (EUM).

Developed by utilities for utilities, Effective Utility Management (EUM) has, since 2007, provided a common framework to assess organizational effectiveness, adopt best practices and metrics, and chart a course toward sustainable operations.  Using the Ten Attributes of Effectively Managed Utilities and Five Keys to Management Success, EUM provides a path for developing and implementing strategic plans and a host of other improvements and can be the foundation of any utility’s path to sustainability, including those that aspire to become a Water Resources Utility of the Future.

As our nation faces the need for greater infrastructure investment better management of finite natural resources, EUM is even more relevant than ever before. That’s why a group of leaders from U.S. water and public works providers of varied sizes came together over the last year to create a revised, easy-to-use EUM Primer. The 2017 Primer provides an overview of the Ten Attributes and Five Keys to Management Success, and explains how utilities of all sizes can use EUM to achieve their mission and strategic goals.

Like most successful management programs, the beauty of EUM lies in its simplicity and clarity.  It provides utilities with a practical, easy-to-implement and common sense process for objectively assessing their strengths and areas of desired improvement.  Utilities set their own pace for charting and tracking their course for improving under EUM. 

Interested in learning more? See the article ‘Effective Utility Management: An update for all of today's public works leaders’ in the February issue of the Reporter. APWA also hosted a Click Listen and Learn on March 30th “Effective Utility Management: Your Path to Sustainability” which can be accessed from the APWA Members’ Library.

Moving forward, we hope APWA members will use the EUM Primer and other materials located at and join the already large number of utilities committed to being ever better 21st century stewards of clean and safe water!


The City of Phoenix wanted to weigh up the broader costs and benefits of implementing various Low Impact Development (LID) features across the city to help inform capital planning going forward. To do this, they enlisted the help of Stantec, Autocase, and Watershed Management Group (WMG) to perform a triple bottom line cost benefit analysis (TBL-CBA).

Using Autocase’s online TBL-CBA platform, the impacts listed in Table 1 were quantified for each of the LID features and then compared against a traditional concrete base case on a per-1,000 sq. ft basis.

At a high level, the results in the table below show that LID features generate positive triple bottom line benefits. On a pure lifecycle cost, we find that Infiltration Trench is the only feature that is cheaper than Concrete – costing almost $2,000 less per 1,000 sq. ft. However, compared to concrete, every LID feature (other than Pervious Pavers) generates enough social and environmental benefit to result in a positive TBL Net Present Value (NPV).

Since runoff does not get treated by a wastewater treatment plant, given that Phoenix has a separate storm sewer system, water quality was a major concern for the City. Instead, runoff passes through either a hydrodynamic separator or a filter catch basin insert before going in to the storm system.

LID can positively influence the water quality in a local area by reducing surface runoff of pollutants. We estimated the value of improved water quality by first modeling the reduced runoff that would be passing through these grey systems due to having LID present on the site. We then equated this resulting reduction in runoff to an avoided capital expenditure and operations & maintenance costs for the grey systems. The water quality results for each LID feature is given in the table below. It is clear that they contribute significant value to the overall TBL results.

Multi-account analyses like these not only answers the questions of “What are the benefits?” and “Who are the beneficiaries?”, but equally important, “How much do they benefit?”. Putting everything in dollar terms allows comparison on an apples-to-apples basis and helps build consensus to the delivery of projects while creating an evidence base to promote a shared responsibility to capital planning for these non-traditional projects.

Simon Fowell
Autocase (by Impact Infrastructure)


Southern California could use single purpose grey infrastructure to help solve their water issues. While grey infrastructure is good at solving one problem, natural systems not only address the primary issue, they perform multiple services – providing co-benefits that generate broader public value.

As municipalities and regional governments transition towards a multi-purpose infrastructure, the region has an opportunity to integrate natural systems to capture and clean stormwater while also creating valuable social and environmental benefits in underserved communities.

Southern California’s Water Challenges: Quantity, Quality, & Reliability

Although an oversimplification, the region’s water challenges can fall in to three buckets (excuse the pun): water quantity, water quality, and water supply reliability.

Water Quantity

SoCal is not known for having a lot of rain in the first place, which limits the area’s ability to capture all of its water needs on-site, but given the amount of paved surfaces, when it does rain, much of this rainfall is turned into runoff. Despite the region’s vast network of dams and spreading grounds which capture billions of gallons per year, there is still room for improvement. If the water that currently flows to the ocean were cleaned of pollutants and infiltrated or directly reused, is could supply millions of people.

Water Quality

Stormwater picks up trash, bacteria, nutrients, chemicals, and heavy metals which then, if not treated on site, go in to rivers, beaches, and the ocean. These cause human health issues, hurt marine life, and degrade ecosystem functions.

Water Supply Reliability

Southern California residents rely heavily on imported water from the Sierra Mountains, the Central Valley and from states as far away as Colorado. As the climate changes, so does the predictability and variability of these alternative sources, which may disrupt supply going forward.

The Value of Nature-Based Systems

Green infrastructure (GI) has surfaced as a versatile solution for addressing the above stormwater challenges in the region. Unlike single purpose grey infrastructure, natural systems do more than tackle the primary problem at hand, generating a variety of financial, social, and environmental co-benefits beyond water quality and quantity...and, being economists, we like to put a dollar value on those impacts.

Water-Based Benefits from Green Infrastructure

Green infrastructure captures runoff and recharges the region’s groundwater, while also reducing the amount of pollutants reaching rivers and the ocean. There are financial, social, and environmental impacts that arise from this.

Other Social and Environmental Benefits from Green Infrastructure

The water-based benefits on their own may not always be enough to overcome the often-higher upfront capital cost of natural systems, which continues to be a hurdle in their wider implementation. Nevertheless, these nature-based solutions simultaneously generate a variety of co-benefits that create tangible value for a variety of stakeholders.

For example, these projects offer recreational amenities in areas that often lack green space, improve public health through exercise and reduced cardiovascular disease, they provide educational opportunities, reduce the urban heat island effect, attenuate flood risk, improve property values, as well as sequester carbon and remove harmful air pollutants.

A larger (but not necessarily complete) suite of impacts from nature-based infrastructure can be seen below.

Putting Theory in to Practice: Showing the True Value of a Project in Southern California

The team at Autocase recently valued the Triple Bottom Line impacts for a large spreading ground enhancement project – one of many green infrastructure projects currently in design in the region. This particular project will increase water conservation by infiltrating an additional 8,000 acre-feet/yr (enough to supply 24,000 homes per year) while also including landscaping, and recreation & education opportunities. The triple bottom line results help build a financial case for similar projects that integrate natural systems.

The results below are for the 50-yr lifespan of the project. Interestingly, the upfront and ongoing maintenance costs (around $59m) are outweighed merely by the financial value of water savings (around $230m). Given the large scale of the project, the social value of water supply reliability is around $60m, and the avoided emissions due to capturing water closer to the end use is valued at around $4m. Once the other social and environmental co-benefits are valued – like recreation, urban heat island, property value etc., it makes for a compelling case to invest in natural systems, with the overall triple bottom line value at almost $250m. For every dollar spent, the project is estimated to return $5.2 in benefits.

Work with Nature, Not Against it

These kinds of results illustrate that natural systems can be integrated to solve major challenges while also saving money and serving the community by creating broader public value. When assessed solely on first cost, it can be difficult to justify their implementation, but once the true value is identified, measured, and monetized, it is clear to see that these projects perform valuable social functions over and above their primary goal – often in communities that lack green space.

By valuing impacts in dollar terms, a diverse portfolio of projects can now 1) be compared consistently and transparently in an apples to apples way, 2) compete for funding, and 3) be prioritized in such a way to generate the greatest bang from the public buck.

Ultimately it’s rarely a binary choice between grey vs. natural systems i.e. the idea isn’t only to use nature or only to use grey. Instead it should be about recognizing the value that natural systems provide and integrating them in to grey solutions to enhance infrastructure projects.

This concept can be summed up nicely by E.F. Schumacher:

“Modern man does not experience himself as a part of nature but as an outside force destined to dominate and conquer it. He even talks of a battle with nature, forgetting that, if he won the battle, he would find himself on the losing side.”
E. F. Schumacher (1973). Small is Beautiful

Simon Fowell, Economist at Autocase