One water: Integrated water resource management is the future
As cities grow, industries develop, and climate-related events appear to accelerate, the strain on water resources is becoming very difficult to ignore. According to the United Nations, global water demand is expected to increase by 20-30% by 2050, with urban areas bearing the brunt of this pressure. To combat the impacts of population growth and climate-related events on water resources, One Water is increasingly emerging as one of the primary strategies for public water utilities across the world.
One Water is the name given to an approach that leaders and policymakers are using to plan and manage urban water sources with the goal of establishing long-term resilience and reliability. One Water policies were established from the concept of Integrated Water Resource Management, which emphasizes the sustainable management of water and related resources to maximize resultant environmental, economic, and social welfare in urban environments. This technique suggests all urban water sources - drinking water, wastewater (cleaned water), greywater, surface water, stormwater, and groundwater - be integrated and managed collectively so that water as a resource is considered holistically. Simply put, there is value in all water regardless of how it originated at the boundary of a given water provider and its planned end use. Every drop counts. Water is increasingly becoming scarce in many areas around the world and providers that do not plan to integrate their water resources are potentially missing opportunities to reduce costs, improve resilience, and be better stewards of this precious resource for future generations. As we work together across our cities, regions, countries, and our planet, we all struggle to meet the demands of growing populations, industrial growth, competing uses, and unplanned events such as regional droughts and fires.
The one water approach
Traditionally, public water resources have been managed in siloed systems, each operated by different agencies with relatively minimal coordination. Moreover, conventional approaches to water management have often prioritized immediate capital and maintenance costs, leading to standardized technological solutions and processes. Under this infrastructure model, stakeholder engagement, including collaboration with the public, technical experts, and developers, is typically restricted to a single project or area. The framework has not existed to consider a broader view across different subdivisions and groups. However, given the advancements in technology and growing recognition of water as a finite and critical resource, the continued reliance on disparate systems seems outdated, unsustainable and economically unviable.
One Water aims to renovate traditional approaches, benefiting the community, economy, and environment at every level. This approach links together all sources of urban water through intentionally coordinated management. Embracing intuitive solutions and green infrastructure, One Water also emphasizes water reuse within the watershed while safeguarding environmental conditions and essential utilities. Considerations for the total water supply are made during urban planning, landscape architecture, and stormwater conveyance efforts where water can be treated, harvested and/or retained to support the appropriate use in the overall increased demand and environmental concerns. Wastewater and surface water can be treated as valuable sources to ease consumer demand through reclamation in either potable or non-potable applications. These collective strategies aim to foster a closer connection between the public and their water supply. One Water efforts intentionally incorporate public input, collaboration, and education. By prioritizing end users and ensuring their involvement in water planning and development, the initiative recognizes that everyone has a stake in their community’s water supply.
Investing in one water strategies: Long-term savings for sustainable water supply solutions
Implementing One Water strategies can often necessitate substantial initial investments from water providers. However, these investments can yield significant long-term cost savings by securing sustainable and resilient water supplies. As groundwater resources become scarcer, costs associated with their use are projected to rise, making traditional water sources increasingly out of reach for some providers. In contrast, One Water approaches, which integrate various water management practices, can offer a cost-effective alternative over time.
In 2023, Texas’ 88th Legislature, established the Texas Water Fund, and provided a $1 billion appropriation for the fund to enhance the state's water infrastructure and develop new water supply projects. Administered by the Texas Water Development Board (TWDB), these funds will provide innovative water supply initiatives, including marine and brackish water desalination, oil and gas-produced water treatment, and aquifer storage and recovery projects. At least $250 million of the funds are allocated to the New Water Supply for Texas Fund.
A fundamental principle of One Water is ensuring equitable access to affordable water for all communities. To uphold this, water providers and municipalities should consider diversifying their water sources to mitigate supply shortages and escalating costs associated with groundwater usage. In Texas, legislative mandates have led several regional water authorities to implement surface water conversion mandates, imposing fees on entities that fail to reduce groundwater consumption. For instance, in Houston, the Harris-Galveston Subsidence District (HGSD) oversees significant disincentive fees for providers that do not meet target dates for converting their uses from groundwater to surface water, as seen in the Schedule of Fees - Harris Galveston Subsidence District. These measures underscore that the financial imperative for municipalities to secure sustainable water supplies can also be based on concerns such as subsidence in addition to scarcity.
While the financial benefits of One Water projects are perhaps not immediate, they will tend to accrue over time as planning and integrated management of already available alternative sources of water become more cost-effective than constructing new water infrastructure. This long-term commitment requires a paradigm shift from short-term cost avoidance to investing in sustainable and resilient water systems. In Texas, the broad support for the Texas Water Fund underscores the recognition that investing in One Water strategies today is essential for securing water resources for future generations.
Advancing one water goals through surface water supply and watershed management
Securing more surface water in potable water systems is a practical first step for Texas water providers to adopt a One Water mindset. With increasing groundwater depletion, a shift toward surface water offers a more resilient approach to meet growing demands. Historically, groundwater has supplied most of Texas' water needs, but this reliance is increasingly no longer sustainable. Surface water reservoirs and watershed management now serve as critical programs to address this issue.
The Brays Bayou Watershed Master Plan, developed by Lockwood, Andrews & Newnam, Inc. (LAN), addresses the stormwater management challenges in Houston, one of the most flood-prone cities in the United States. Covering approximately 128 square miles, the plan integrates advanced 1D and 2D modeling techniques to assess the capacity of over 1,000 miles of storm sewer systems and their interaction with the Harris County Flood Control District channels. The plan identifies hidden flood risks by simulating various storm events, from 2-year to 500-year floods, and provides a detailed analysis of local drainage infrastructure, including storm sewers, ditches, culverts, and streets. The development of a Flood Damage Index and Severity Ranking tool further aids the city in prioritizing mitigation efforts based on risks to critical infrastructure and mobility. This strategic and proactive approach enhances urban flood resilience and sets a new standard for sustainable stormwater management, ensuring effective resource allocation and long-term sustainability for the community.
The Brays Bayou Watershed Master Drainage Plan pinpoints potential overflow points between sanitary and stormwater systems, taking an initial step toward aligning with the principles of the One Water approach.
One water starts with one plan
To successfully adopt a One Water approach, municipalities can begin with a comprehensive and integrated master planning process that incorporates stormwater, wastewater, and potable water systems into a unified framework of resources. Historically, master plans for these systems have been separated, each focusing on capital improvements, budgets, and operational goals. However, the growing need for resilience and sustainability in water management increasingly necessitates a shift toward integrated water resource planning. Integrated planning leverages scenario-based simulations to equip providers with funding and solutions to address long-term effects related to population growth, industry, and unplanned climate-related events. The success of integrated water resource management depends on collaboration among elected officials, certified planners, modeling experts, and associated professionals.
Kendall Crawford
Kendall Crawford is a project engineer with the Houston Infrastructure Water Conveyance team at Lockwood, Andrews & Newnam, Inc., specializing in water resources modeling and planning. Over the past five years, she has contributed to water resources master planning and capital improvement projects, performed hydrologic and hydraulic analyses, created and managed GIS databases, and performed feasibility studies, with special emphasis on large diameter water line design. Kendall holds a Bachelor’s degree in Biological and Agricultural Engineering from Texas A&M University, earned in May 2020. She currently serves on the TAWWA State-Level DE&I Committee and on the TAWWA Southeast Chapter Young Professionals (YP) Committee.
