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The following was originally written for and submitted to the Texas Water Development Board as feedback on how to use the $1 billion Texas Water Fund to “create” some “new” water supply.

Two roads diverged in a wood, and I—

I took the one less traveled by,

And that has made all the difference.

• Robert Frost

In considering the rollout of the Texas Water Fund, it was noticed that the heading of one of the surveys sent out by the Texas Water Development Board seems to indicate there is a bias cooked in for certain sorts of water projects – more on that below. What is offered here is another look at water resources management, one that suggests it will be beneficial to our water economy if we apply and implement a broader vision of how we manage water, and that may make all the difference in just how effectively we can “create” any “new” water supplies. So let’s take a peek down that road not taken … so far.

Regarding that apparent bias, many years ago now a blog post entitled “They’d rather have a root canal …” was published, which noted that the mainstream of the water resources management field was all over actions that could be implemented at the beginning of the pipe – e.g., desalinization – or at the end of the pipe – e.g., direct potable and “purple pipe” reuse – but it seemed they would rather have a root canal than delve into how anything in between the beginning and end of the pipe might be rethought, re-planned, re-engineered, to produce systemically more efficient systems. This missive delves into that and elucidates such opportunities.

It starts with broad systemic thinking, of the sort set forth on the Waterblogue in One More Generation. It is reviewed there how it seems society “thinks” that a “reasonable” strategy is to raid remote aquifers and transport that water, in “California style” long-distance water transfer schemes, to areas which are growing, so presumed to “need” that water supply. It appears that little consideration is being given to the long-term sustainability of the aquifers being raided. As a prominent water professional once observed, our groundwater is being “managed to depletion”. By depleting that water, we would grow a population over the next 50 years or so that (we hope anyway) would not then dry up and blow away, will still be here, still needing water supply for the next 50 years, and so on after that. So it seems this would be a plan to run society into a box canyon, to be just rearranging the deck chairs as the ship goes down, leaving future society high and dry. So it is suggested that we consider how we can “create” some “new”, and renewable, water supply as part and parcel of the development that will serve that growth.

Look! Up in the Sky!

Let’s begin that broad systemic thinking with consideration of building-scale rainwater harvesting (RWH) vs. watershed-scale RWH as the basis of water supply. Of course, since almost all of our conventional water supplies ultimately derive from precipitation, they are all watershed-scale RWH systems, with the watershed being the collection surface, and streams, reservoirs and aquifers serving as the “cisterns”. So first, it should be understood there is nothing “different”, nothing “exotic” about the very idea of building-scale RWH as a water supply strategy. We simply have to consider it more systemically than we have, in the main – a road not taken … so far.

As is reviewed in a piece on the Waterblogue entitled Water for DFW – Building-scale rainwater harvesting vs. Marvin Nichols, the systemic differences in the two approaches to “growing” water supply favors, even highly so, the building-scale strategy. These differences include:

• eliminating transmission losses;
• eliminating the energy cost of long-distance transmission;
• eliminating lake evaporation losses;
• avoiding the environmental and economic disruption and destruction that building reservoirs entails;
• allowing simpler and less costly water treatment for potable supply;
• minimizing or eliminating climate change impacts (oh, wait, we can’t talk about that in Texas, sorry);
• water savings due to it taking less energy to deliver the water supply – the so-called water-energy nexus;
• lower impact on environmental flows;
• matching up the timing of costs to implement supply more closely with imminent need for supply, the so-called “time value of money”, understanding that under the watershed-scale RWH strategy, a whole lot of investment must be put in the ground before water supply can be provided to the first house or business, while under the building-scale RWH strategy, the supply for each building is installed on a “just in time” basis; and
• because of this, there would be a much lower investment put at risk.

It is noted in passing that some folks are touting transmission line loss control as the epicenter of how we can “create” some “new” water supply, by better husbanding the water we already have. While of course any and all conservation efforts must be a necessary component of this whole effort, it is observed that this simply highlights the flawed nature of the watershed-scale RWH water supply strategy. Even with the very best loss control deemed feasible, there would still be considerable transmission losses. Maybe “good enough” as long as water supply doesn’t get too tight, but maybe too big a chunk out of supply when it is tight. So it is asserted that a better way to blunt those losses would be an infrastructure model that would pretty much completely obviate line losses, the building-scale RWH strategy.

Yet, we have seen no meaningful consideration of building-scale RWH as a broad scale water supply strategy. To the extent it is considered as a strategy at all, that is sequestered to individual building owners, evaluated in a micro-economic climate that does not take into consideration any of these systemic advantages; the long-run economic analysis is pretty universally ignored. So it is asserted that this is an arena ripe for investigation, with the potential for yielding huge amounts of “new” supply over much of the state in a globally cost efficient and resource efficient manner. The Texas Water Fund should direct resources toward broad proliferation of building-scale RWH.

Waste Not, Want Not

The other major arena in which better systemic thinking is needed is wastewater reclamation and reuse. As noted, there is a mainstream bias for understanding reuse pretty much exclusively as something that would be appended on to the system at the end of the pipe, really as if it is just an afterthought rather than a central function. It is suggested that this whole paradigm be rethought, that we focus on designing reuse right into the very fabric of development, as if it indeed were a central function of this societal process we call wastewater management.

To do this would entail reconfiguring the wastewater system architecture, so that this water resource would be treated, and reused to the maximum extent feasible, as close to where this water is “generated” as practical. Of course the rub here is “as practical”. The mainstreamer “understanding”, even codified in TCEQ rule, is that wastewater is “best” managed on a “regional” basis, urging the routing of flows from as far and wide “as practical” to one point source.

That reconfiguration of wastewater system architecture was labeled the “decentralized concept” of wastewater management back in 1986, set forth as an alternative organizing paradigm for a wastewater system of any overall scale. All that was based on works prior to that, so really there is nothing “new” about the decentralized concept strategy; it too is just a road not taken … so far.

As has been reviewed in many works, the “regional” system is really just the product of 19^th century tradition, when, with the stuff running in the streets, the whole focus was on piping it “away”. That tradition has simply been “extended”, with no thought on whether that would be the best manner of managing this societal function in the dynamic development market, and with the water supply challenges, we have in Texas today. It is high time that society engages in that rethinking and considers the systemic efficiency of distributed vs. “regional” systems.

A look at just how the decentralized concept could be implemented in a hinterlands development in the Hill Country is set forth on the Waterblogue in This is how we do it. A comparison of this strategy vs. piping such a development into a “regional” system is offered in Let’s Compare. As these works review, using the decentralized concept strategy in lieu of the conventional “regional” strategy can deliver fiscal, societal and environment advantages.

In the fiscal arena, we can realize several advantages:

• With the treatment units being distributed to the “neighborhood” scale, all of the large-scale collection system infrastructure, trunk mains and lift stations, would be obviated. As the collection system is typically a large majority of total “regional” wastewater system cost, this would impart a huge cost savings.
• For any local collection system that is needed, the effluent sewerage concept would be favored, rendering those lines more cost efficient, as reviewed on the Waterblogue.
• Little to no infiltration/inflow would plague the effluent sewerage collection systems, decreasing maintenance costs and peaking loads on treatment units, allowing some components to be downsized.
• Using effluent sewerage renders the sludge management function more cost efficient, and otherwise less burdensome.
• With treatment units distributed, the reclaimed water redistribution system would also be smaller scale, thus far less costly than “purple pipe” systems redistributing water from “regional” plants, so rendering reuse more affordable, thus more fiscally feasible, delivering cost – and sustainability –  benefits by displacing demands on the potable water system.
• The distributed system architecture would also typically obviate pumps (lift stations) in the collection system, so saving all that energy, saving money.
• The type of treatment unit we need to employ in the distributed treatment units – the High Performance Biofiltration Concept (recirculating packed-bed filter) unit is highly favored, as reviewed in This is how we do it – would incur fairly minimal routine O&M cost.
• The High Performance Biofiltration Concept treatment unit would require a lot less energy to operate than an activated sludge system, practically the knee-jerk choice by the mainstreamers, so saving a lot of money.

Societal implications would be significant. More fully reviewed in Let’s Compare, those implications are listed here:

• As noted above, reuse of effluent would become more cost efficient.  The effluent would be made available throughout the service area, nearer to points of potential reuse, greatly decreasing the cost of the reclaimed water distribution system.  Non-potable demands such as landscape irrigation, toilet flush supply, and cooling tower makeup could be more expeditiously and cost efficiently served with reclaimed water, spurring on this action, so defraying demands on the our increasingly stressed water supplies.
• Requiring far less energy for treatment and to move water around, this distributed treatment and reuse would also reduce greenhouse gas emissions (oh, sorry again to mention climate change, but this IS a societal advantage).
• The management system would be able to accommodate any level of water conservation found to be economically attractive or ecologically necessary.  Only liquid effluent is transported, so reduced wastewater flows due to water conservation measures would not cause clogging problems in the collection system, as has occurred in conventional centralized systems.
• The decentralized concept system is easier to plan and finance.  Each project is small compared to the typical “regional” system expansion.  The management needs of each area or new development are considered directly and could be implemented independently. Contrast this with planning large-scale facilities over an area-wide system, with much less definite growth prospects in any given area.
• Capacity expansion – and therefore capital requirements – would track demand much more closely, minimizing the amount of money spent to construct facilities which would not be fully utilized for years to come, as occurs routinely in the course of expanding and upgrading conventional centralized systems. Again, the “time value of money”.
• Much of the cost could be privatized or assigned directly to the activity generating new demands on a much fairer basis, so that existing ratepayers and/or taxpayers would not have to serve as the “bank” for this infrastructure, which is typically the case as upgrades and expansions of the conventional centralized system are bond financed by public agents.
• This is all money “at risk”. If, for example, we were to experience another “crash” such as occurred in 2008, the pace of development might slow, even stop altogether for a time. But once the money is borrowed and the system built, the payments would be due whether development came on line to fund those payments or not. So whoever financed that infrastructure would be on the hook to make those payments. If these facilities were publicly financed, it would be all of the ratepayers, and/or taxpayers, who would be called upon to pony up. This could balloon their wastewater rates and/or tax bills. All that would be avoided under a decentralized concept strategy, which assigns that risk to the developer, who would be putting relatively small amounts at risk at a time.
• With the hardware systems decentralized, there would be no compelling reason to impose a “one size fits all” management approach.  Different strategies could be employed in various parts of the service area, responding in the most fiscally efficient and environmentally responsible manner to each set of circumstances – e.g., on-site systems in low density development, distributed systems on the urban fringe and in the hinterlands, connection to a centralized system where that might be the cost efficient strategy – with all those systems under one unified management system.
• The system can be designed and installed in a manner which is “growth-neutral”, whereas centralized systems often spur growth, even requiring it to be fiscally viable in many cases.
• Distributed management reduces vulnerability to pollution.

This leads us to considering the environmental advantages of the decentralized concept strategy, which include:

• Scale is a major driver of environmental vulnerability. Centralization causes large flows to be concentrated through one pipe or lift station or treatment plant.  This implies that any mishap would have large consequences.  In a decentralized concept system, the flows at any point remain small, implying less environmental damage from any mishap.
• In a distributed system, any mishap that may occur would impact on only a minor portion of the overall system, as each distributed system is disconnected from all the others, so imparting far less overall vulnerability.
• In any case, bypasses, leaks, overflows, etc., would be far less likely in a decentralized concept system. More “fail-safe” treatment technologies would be employed, and lift stations would be eliminated or greatly reduced in number.  Carrying only liquid effluent to multiple treatment centers, the effluent sewer collection system would consist of shorter runs of smaller pipes containing fewer openings, implying far less potential for infiltration and exfiltration and for overflows.
• There would be less environmental disturbance from system construction.  The smaller effluent sewer collection system pipes would be installed at shallow depths and could be more flexibly routed.  There would be no large interceptor mains, which typically run in riparian areas, requiring these riparian environments to be disturbed to install the mains.
• Environmental disturbance would be minimized over the long term as well because existing lines would not need to be torn up to upgrade system capacity.  System expansion would be afforded by adding a new treatment center for each newly developing area rather than by routing ever more flow to existing centers.
• Treatment and reuse can be “tailored” to the waste stream.  Industrial waste need not be commingled with domestic wastes; rather these generators can be required to implement treatment methods specific to their wastewater characteristics and reuse opportunities.

While all these fiscal, societal and environmental advantages should be creating high incentive to consider organizing wastewater systems in accord with the decentralized concept, most important here is the ability to more cost efficiently route the reclaimed water to beneficial reuse, so spurring on that practice, thereby defraying demands on our increasingly stressed water supplies. In regard to the Texas Water Fund, that of course is the main reason to move management in that direction. Again by designing reuse into the very fabric of development, this can “create” a “new” water supply in a far more fiscally efficient manner than can generally be done under the conventional “regional” system paradigm. So the Texas Water Fund should direct resources toward proliferation of reuse-focused decentralized concept “waste” water systems.

Don’t Drain It, Retain It

Before proceeding, it is noted in passing that sustainable water can be enhanced by moving storm water management practice to distributed Low-Impact Development (LID) strategies, for example as outlined on the Waterblogue in … and Stormwater Too. Rather than draining “away” the increased runoff created by development, it should be retained and infiltrated, so as not to desertify the landscape as it is developed. Some of that increased runoff could be captured and directly used for water supply. As reviewed on the Waterblogue, rainwater harvesting for irrigation supply – and in settings where those uses come into play, for toilet flushwater supply and cooling tower makeup supply too – can readily be integrated with the storm water quality control function.

Really, this is a subset of the building-scale RWH strategy. Attention specifically to this is merited, however, as there is a considerable market for this practice, in both new development and in retrofit projects. So this is a road now being partially trod, but the journey lacks much institutional support; it is largely driven by individuals considering their immediate needs. Thus in regard to how society is proceeding to consider how we “create” any “new” water supplies, this too is a road not taken … so far. The Texas Water Fund should direct resources toward expanding these storm water management practices.

Examples of the Opportunities

To illustrate the currency of these manners of “creating” any “new” water supplies, let’s look at some examples.

The first example is a small-bore project, but one that if repeated over and over could add up to a whole lot of “new” water supply. It is a hinterlands project in the Hill Country, called Lunaroya, proposing 28 lots with areas between about 1.5 and 2.5 acres each, located on Barton Creek. The conventional plan for water supply would entail a public water supply well, storage tank and distribution system, all of which would have to be planned, designed and permitted “up front” as a Public Water Supply System (PWSS). It was reported that the water quality out of the well would be such that reverse osmosis (R.O.) treatment would be needed to render the water to potable quality, and this treatment would result in something like 70% of the water supplied from the well becoming R.O. “reject” water, a brine toxic to plants, and so there would have to be a “disposal” system for that water created as well.

It is suggested that all this waste could be obviated by using building-scale RWH for water supply to the houses in Lunaroya. In this area, these acreage lots will be rather expensive, so it is to be expected that houses built there would be “large”, with the roofprint area needed to make RWH systems highly sustainable being installed as a matter of course, between the house, the garage, and covered porches and patios. This leaves the cistern and the rainwater treatment unit – a simple cartridge system and UV disinfection unit – as “extra” costs for an RWH system at each house.

By going with building-scale RWH, not only is the high level of water waste out of the well obviated, but so are the costs of the well, the storage tank, the distribution system, the brine disposal system, and all the planning, design, and permitting costs of those components. This would save the developer a very large sum in up front costs that would need to be paid before water service could be provided to the first house in Lunaroya. This savings could translate to lower lot prices, so defraying the cost of the cistern. Since the RWH systems for each house would be planned, designed and implemented by the owner/builder of each house, all the developer would need to pay up front for water supply would be for the planning items specified by the county as part of the platting process in subdivisions proposing building-scale RWH as the water supply strategy, a very minor fraction of all those up front costs for the conventional water supply system.

As for marketability of houses that use building-scale RWH for water supply, there are hundreds of houses using this supply strategy in the general area where Lunaroya is located. So it is a well known commodity, which can readily be financed by lenders. With a bit of education, some modeling to show how sustainable this supply can be made, this strategy should readily be rendered “non-scary” to any potential buyers of lots in Lunaroya. It is also reputed that rainwater is a superior water supply, being naturally soft, so gentle on skin, clothes and fixtures, that people who use it love it. So the developer would have no reason to fear the lots could not be marketed.

For “waste” water management, it was proposed to use On-Site Sewage Facilities (OSSFs), more popularly called “septic systems”. In particular, it was asserted that a spray field be sited on each lot to “dispose” of this “waste” water, after pretreatment in a home-sized bastardized version of the activated sludge process, commonly called an ATU – “aerobic treatment unit”. So really it is proposed that 100% of the water to be drawn from the well would be wasted, about 70% directly as R.O. reject water and the other 30% or so being “disposed of” – thrown away – after being used once in the house.

It is suggested that the OSSFs be recast as reclamation and reuse systems. Each one would be composed of a High Performance Biofiltration Concept treatment unit, which would remove the majority of the nitrogen from the “waste” water – important in the Barton Creek watershed – feeding the effluent into a subsurface drip irrigation field, arrayed as much as practical to irrigate landscaping that would be irrigated in any case. This type of OSSF has been designed, permitted and installed in several jurisdictions in Texas for almost 30 years now, so is a well known, well understood type of “septic system”.

By this means, a large majority of the “waste” water generated in the house over the annual cycle would be beneficially reused for irrigation, so greatly defraying demands on the potable water supply to the house. For the owners of houses in Lunaroya, defraying irrigation demand would allow them to downsize their RWH systems – the roofprint area and cistern volume – while still maintaining high sustainability of that water supply and maintaining some irrigated landscaping.

The cost of implementing this form of OSSF would not be all that much more than what the ATU-spray system would cost. Especially since the drip irrigation field would in some part displace an irrigation system that would be installed in any case, if the homeowner intended to maintain any irrigated landscaping.

Thus it’s apparent that the alternative scheme, a set of “One Water” strategies, would save a whole lot of water. 37 acre-feet per year is being requested to be permitted by the governing groundwater district. This calculates out to be an average demand of 1,180 gallons/day per house. Note again, only about 30% of that flow, or about 350 gallons/day per house, would be a usable water supply; the rest would become R.O. reject water, an utter waste of this water, greatly downgraded in quality by the R.O. treatment, and so posing an expense for proper “disposal”. Going with building-scale RWH instead, society would save all that water, the developer would immediately save a large sum for all those obviated up front costs of implementing the PWSS, and the residents would enjoy the superior quality of the rainwater supply. This is a win-win-win, for the developer, for the homeowner, for the water environment. It is the sort of action that the Texas Water Fund should have some mechanism for fostering.

The next example is the Mirasol Springs project, presently in the planning and permitting stage, along the Pedernales River near where it is crossed by Hamilton Pool Road. The development comprises an Inn, restaurants, some large “conservation” lots, some “branded residential” houses, “resort cottages”, an event barn, a University of Texas field research station, and a farm. The situation is described on the Waterblogue in If you’re going to call it a vision …, reviewing how the developer is presuming to call a very conventional set of water resources management practices a “new standard for environmentally focused Hill Country development”. It is suggested that an actual “new standard” would be a “total One Water” scheme, essentially following the water supply, wastewater management, and storm water management concepts set forth above. The basics of this program would include:

• All the houses on the “conservation” lots, arrayed on both sides of the environmentally sensitive Roy Creek Canyon, shall have water supply provided by building-scale RWH.
• All the houses on the “conservation” lots shall have wastewater service provided by OSSFs, using nitrogen-reducing recirculating packed-bed filter (High Performance Biofiltration Concept) treatment units and dispersing the reclaimed water in subsurface drip irrigation fields, arrayed to the maximum extent attainable to irrigate the highest value landscaping on the lot, landscaping that would likely be irrigated in any case, to minimize need for harvested rainwater for irrigation.
• Together, these strategies will obviate all water and wastewater lines running through/across Roy Creek Canyon, eliminating that source of water quality degradation and saving the developer the budget of a small African nation in upfront costs that would deliver a very limited amount of service.
• All the developer would have to do to market those lots is plat them and provide road access. Paying for and installing the RWH systems and the OSSFs would fall to the owners/builders on each lot.
• Savings on the obviated water and wastewater lines would be far more than the cost of a tanker truck, which the manager of the overall water supply system could use to provide any backup supply to the houses, if ever needed, to provide high assurance of backup water supply at need to these homeowners. In the meantime, with it being needed only rarely, that truck could be leased out or used for other needs, to defray its cost.
• This same strategy may be applied to the “branded residential” houses, similarly eliminating up front costs for the developer, obviating water distribution line runs and wastewater collection and reuse redistribution lines, and their costs and environmental liabilities. Also reducing the capacity needed in the surface water and/or groundwater supply and wastewater management systems, so reducing those costs, which the developer will have to pay up front.
• This same strategy may also be readily applied over the “resort cottages”, where all units are likely to be on a single lot under single ownership, so a collective RWH system and a collective OSSF would be readily doable, institutionally as well as technically. Again, saving on water distribution lines and wastewater collection and redistribution lines, and eliminating their environmental liabilities. And further reducing the capacity needed in the surface water and/or groundwater supply and in the wastewater management system. Noting that due to the nature of this service, this RWH system may have to be permitted as a PWSS, but that is readily doable, and that PWSS could very readily be operated by the entity established to run the overall water supply system.
• Building-scale RWH for water supply and an OSSF for wastewater management could also service the research center. In particular as it appears this facility would be “off to the side” at some distance from other facilities, this would save on water distribution lines and wastewater collection and redistribution lines, and again reduce the capacity needed in the surface water and/or groundwater supply and the wastewater management system. All of these costs could likely be shunted off to the entity that develops and builds the research center facilities, so here too reducing the developer’s up front costs.
• It appears practical to use building-scale RWH for water supply and an OSSF for wastewater management for the event barn. Again, savings on water and wastewater lines, savings in water supply capacity, and elimination of environmental liabilities that wastewater lines would entail.
• This leaves “only” the Inn and the restaurants to be provided water supply from surface water and/or groundwater. Even for those facilities, however, rainwater supply off those roofs can defray water demands. Here again, even if the RWH system would need to be permitted as a PWSS.
• Consider using slow sand filter for the surface water treatment process, a system very well suited to treating river water. Likely less expensive to build – could readily be phased as needed, installing multiple beds – and far less expensive to operate and maintain than the conventional water treatment plant that the developer is proposing.
• The Inn and restaurants would have design flow rates above 5,000 gpd, so the wastewater system(s) to serve those facilities would have to be permitted at TCEQ under the “municipal” permitting process. But the form of such systems could be the same as the OSSFs, using the highly stable and robust nitrogen-reducing recirculating packed-bed filter (High Performance Biofiltration Concept) treatment unit – rather than the inherently unstable, high operating cost activated sludge unit, which would need cost increasing modifications to attain significant nitrogen reduction – and dispersing the reclaimed water as much as practical to irrigate grounds beautification. Understanding that the subsurface drip irrigation fields to irrigate that landscaping would be in effect the “TLAP” fields for this system. Installing drip fields in the “waste meadows” could be largely, if not completely, obviated. All of this will also decrease the developer’s up front costs.
• The “farm” is a wild card, but it is quite likely that everything but crop irrigation (but maybe some of that too) could have water supply provided by building-scale RWH and all wastewater generated there could be managed in an OSSF. It may be that some of the drip irrigation field receiving reclaimed water from the Inn and restaurants could be on the farm, irrigating some of the crops.
• There should also be discussion of the form of storm water management facilities. Note that a very robust program of rainwater harvesting will basically take rooftops “out of play” in regard to storm water quality management, and reduce the scale of water quantity management (detention) facilities. Maximizing use of permeable pavement would also reduce need for water quality management installations. All this too is quite likely to reduce the developer’s up front costs.

The developer has applied to use surface water from the Pedernales River and groundwater from the local aquifer to provide water supply for this project. The adoption of this “total One Water” set of strategies would obviate a large portion of those draws on these sources, each of which is understood to be rather limited. Indeed, it is the expectation that both surface water and groundwater supplies might be curtailed during future droughts that motivated the developer to apply for access to both supply sources.

Given the clear opportunity to render the water resources management infrastructure more fiscally efficient, including the “time value of money” benefit of being able to defer installation of infrastructure until the building it serves would be built – noting this project has a projected 10-year timeline to completion – and higher quality of rainwater supply, the “total One Water” set of strategies presents a win-win-win prospect for the developer, for society, and for the eventual users/residents of this project. That it appears this sort of approach is currently being ignored by the developer illustrates the need for the Texas Water Fund to include some means of promoting, maybe even incentivizing, the move toward sustainable water practices, so as to proliferate them throughout the development community.

Those two examples are out in the hinterlands, so not entailing how to apply these concepts within the context of a community-scale utility system. For that, we look first at the situation facing the City of Liberty Hill. The city has applied to TCEQ for a permit to increase the capacity of its wastewater system from 2 Mgd to 4 Mgd. This shows that a lot of the future flows would derive from new development, and that would be mainly located on the urban fringe and in the surrounding hinterlands. Which in turn suggests that, for all the reasons reviewed above, the city might consider moving to a decentralized concept strategy to serve that growth, rather than to expand the capacity of its centralized point source treatment plant and extend sewers ever further into the hinterlands.

This strategy may be doubly beneficial to Liberty Hill because the new permit carries with it a more stringent restriction on phosphorus concentrations in the effluent to be discharged into the South San Gabriel River. This was imposed because the current discharge has stimulated massive algal blooms in the river, contended to be a violation of the Clean Water Act. So, while the city would have to take measures to reduce effluent phosphorus concentration in the existing flow, they can save money by not having to increase the capacity of the phosphorus removal process(es) for the additional 2 Mgd of flow. Particularly since none of that flow currently exists, so the investment required for increasing the central point source treatment plant capacity would be money that would not be fully utilized for many years into the future. The “time value of money” thing again.

It was communicated to the Liberty Hill mayor and city council members how they could go about moving to a decentralized concept strategy to serve new development in and around the city. And perhaps to even “unhook” some existing development, using the “sewer mining” strategy. Then perhaps to also install a “purple pipe” system from the central point source treatment plant to minimize the amount of water that would need to be discharged into the river. By these means, they could reduce the considerable investment needed for phosphorus removal processes.

As argued above, it is to be expected that by going with the decentralized concept strategy to serve new development, the city could expand its wastewater system capacity at lower cost, and – again the major point here – would put a lot of that wastewater to work for society, beneficially reusing it to defray demands on the area’s water supply sources. Blunting any future “need” to import water from remote aquifers, and all its attendant inefficiencies, and apparent unsustainability, as was reviewed above.

What is not addressed in those communications is that there would also be opportunities to make building-scale RWH part and parcel of the water supplies for the new development. Together with the “new” water supply “created” by reusing rather than discharging the flows from all these sources, there is a win-win-win to be had here, for the city’s ratepayers/taxpayers, for the developers, and for society by moving practice toward sustainable water. Again highlighting how the Texas Water Fund needs to create some means of promoting, perhaps incentivizing, the move to sustainable water practice, at all scales.

The last example offered is the “Zero Net Water” concept that had been posed a decade ago, proposing to maximize building-scale RWH, condensate capture, and building-scale/campus scale wastewater reuse to provide water supplies, an exponent of the strategies reviewed above. One example of this has been set out by Texas Water Trade (TWT) just recently as part of its Strategic Plan, which they have labeled as “Net Zero Water”. As TWT styles it, this concept – which is well set forth in its Net Zero Water Toolkit – is largely envisioned to be mainly applied in “big box” projects, like large institutional or commercial buildings. But of course as reviewed above it could also be applied in many sorts of developments, at various scales.

The explicit opportunity to cost efficiently expand the Zero Net Water strategy to smaller projects, explicitly in regard to wastewater reuse, is reviewed on the Waterblogue in Appropriate Technology. This hinges on moving to technologies better suited to distributed deployment, rather than simply scaling down the conventional technologies used at large centralized treatment plants.

However it is done, going with the Zero Net Water strategy would “create” considerable “new” water supply, through building-scale RWH, condensate capture, and distributed wastewater reuse. While market forces are already moving this strategy forward – and as noted it could be cost efficiently extended into markets that appear to be not currently recognized – this is another arena in which the Texas Water Fund could promote and incentivize that move, relieving stress on the watershed-scale RWH systems, saving a whole lot of water for society.

Stimulating Action

While the arguments for moving water resources management practices toward sustainable water are solid, compelling even, it is clear that the mainstream “thinking” in this field does not, in the main, recognize those practices. Thus there is little if any such change in practice showing up in regional water plans, and so in the State Water Plan. Evidencing, as is suggested throughout this document, that measures to proliferate the vision, knowledge and skills required to put these sustainable water practices on the ground need to be stimulated and pursued.

It is suggested that, in terms of the programmatic/bureaucratic activities that create the regional water plans, there needs to be a more inviting forum, that would encourage the pursuit of the sorts of sustainable water practices as have been highlighted herein. Attendance at a regional planning group meeting has been an experience of sitting through mind-numbingly programmatic/bureaucratic discussions and machinations, with such ideas as basing broad scale water supply strategy on building-scale RWH or the decentralized concept of wastewater management never even coming up for discussion. Much less is there any consideration of incorporating any of that into the regional plan. Rather, everything is focused on extending and perpetuating practices that constitute business as usual in the water resources planning and engineering field. Indeed on such actions as desalinization at the beginning of the pipe or direct potable and “purple pipe” reuse at the end of the pipe, neglecting how we can rethink, re-plan and re-engineer anything in between. It seems they would rather have a root canal …

Because of this groupthink being “expected”, it remains quite difficult to gain any traction in getting those who would implement water resources management infrastructure – municipalities, utilities, developers, etc. – to even entertain a peek down the road not taken. So there is much work to be done.

We began this missive with the closing lines of a Robert Frost poem. Let’s end it with some more poetry, these song lyrics by Neal Peart of the band Rush, from “Vital Signs”:

Leave out the fiction
The fact is this friction
Will only be worn by persistence

Leave out conditions
Courageous convictions
Will drag the dream into existence

So who is going to apply the persistence, who will impart the courageous convictions, who is going to drag the dream into existence? Who will lead in taking a peek down the road not taken … so far? If Texas is to avoid a dark water future, perhaps becoming unable to accommodate more growth, or even to maintain beyond one more generation the currently occurring population growth, that is being bought by “managing to depletion” existing water supplies, it must consider how to move practice toward sustainable water. And that could make all the difference.