EXECUTIVE SUMMARY OVERVIEW OF THE PROJECT ORGANIZATION OF THE REPORT FINDINGS POLICY RECOMMENDATIONS

EXECUTIVE SUMMARY

Overview of the Project

Supported by University of Hawaii Community Design Center (UHCDC) and State of Hawaii Office of Planning, this project provides infrastructure planning suggestions for the City & County of Honolulu and the State of Hawaii to meet the established goals for Transit Oriented Development (TOD) in Waipahu, particularly for the state-owned land. Through a graduate course PLAN 642 Urban Infrastructure Planning, students and graduate assistant in Urban and Regional Planning department (DURP) at the University of Hawai‘i Mānoa (UHM) participated in the project and obtained service learning opportunities through academic instruction, site visit, and interaction with the practitioners, government agencies, and the general public. The project is part of a teaching practice and outreach initiative led by the UHCDC. The initiative provides a platform for students, faculty, and partnered professionals to collaborate on interdisciplinary applied research, planning, and design projects that serve the public interest. This project particularly addresses the infrastructure concerns for the statewide TOD development using Waipahu as a case study.

The project is organized into three phases; review of the existing condition and community needs, future demand analysis, and policy recommendations. In the first phase, students evaluate the existing condition in field trips under the guidance of practitioners from state and city and county agencies. To understand the community’s perception and needs for infrastructure improvements, they also conducted a community survey during the field trip. In the second phase, students and graduate assistant collected data, interviewed key stakeholders, and applied the analytical methods learned in PLAN 642 to estimate the future travel demand, stormwater runoff, and sewer discharge for the build-out scenario. Lastly, to address the problems identified, best practices are reviewed to make suggestions for the study area. Suitability studies are conducted using geographical information system to find the most suitable areas for implementing the suggestions.

Organization of the Report

The report is comprised of seven chapters in three parts, covering an overview of existing conditions, capacity and community needs assessment, estimation of future demand, best practices review, and suggestions of policy tools.

This Executive Summary begins the report, summarizes objective of the report, findings, and policy recommendations. The remainder of the report is divided into three parts:

Part I: Introduction and Background - comprises two chapters summarizing the current condition of infrastructure and facilities in Waipahu, and the prevalent issues and needs for improvement revealed through existing study review and community survey;

Part II: Future Scenario Analysis - is composed of two chapters on build-out analysis and suitability analysis. The build-out analysis is conducted for a maximum development scenario based on current TOD zoning and stakeholder interview. The analysis estimates the future travel demand, parking needs, stormwater runoff, and sewer projection. The suitability analysis then identifies areas in need of improvements given the identified problems;

Part III: Recommendations - summarizes the lessons learned and policy suggestions considering local characteristics, city goals, and the review of best practices from the literature.

Findings

1. For transportation planning, it is found that a maximum build-out scenario for the state parcel in Waipahu would significantly increase the traffic on adjacent roads, especially for Mokuola street and Waipahu street. The maximum development would also increase the parking demands by seven times. To reduce the congestion and fulfill the needs for parking, either the capacity of the adjacent roads and parking lots needs to be expanded or strategies promoting non-auto based trips need to be prioritized.

2. To facilitate non-auto travel in particular, there are high needs to improve the multimodal transportation facilities along Paiwa St., Farrington Hwy, Awainui St.,

Mokuola St. Farrington Hwy. Awalau St., and Farrington Hwy.

3. For stormwater management, development of state parcels and the TOD area in general would increase the overall stormwater runoff in the watershed by 12.6%, which would make the existing flooding problem worse. However, to solve the flooding problem, would require efforts at the watershed scale. Without upstream mitigation, grey infrastructure or retention/detention ponds, it would need approximately 80% of the

TOD development to be green spaces/pervious surfaces in order to keep the future runoff at the current level.

4. Suitability analysis identifies areas such as such as Waipahu Depot, Farrington Hwy and the state parcels are suitable for green infrastructure in the watershed.

5. For wastewater discharge, under the maximum build out scenario, the state parcels could generate almost eight times the current sewer discharge. Considering the capacity of 24’’ sewer main is 1.78 times of the 18’’ sewer main, it means that if the current volume/capacity ratio for the 18’’ sewer main exceeds 17.8%, there would be a need to upgrade the 24’’ sewer main pipe in future.

6. Finally, there is a need to examine the condition and needs for other utilities such as water and power if data become available in future.

Policy Recommendations

1. Improve of public transit, pedestrian, and bicycle facilities and services. Waipahu TOD would benefit from a reduction in future traffic and parking needs if public transit and walking friendly environment are prioritized. It is recommended to improve the an extensive network of pedestrian and bicycle facilities, add more bus connections with more frequent services, and implement strategies such as bus-only lanes where possible;

2. Encourage shared and adaptable parking. To reduce and accommodate the future parking needs, it is recommended to eliminate minimum parking requirements, implement districtlevel parking maximum, adopt regulations and incentives encouraging shared-parking, as well as regulations allow new parking structures to be adaptable to other uses to anticipate the emerging trends (e.g. autonomous shared vehicles, sea level rise). Compact mixed-use development as one objective of the TOD, is a catalyst for increasing parking efficiency and reducing the amount of parking needed in the area;

3. Adopt Green Infrastructure. Both the existing study and students’ community survey suggest the community’s strong interest in walkability, provision of green spaces for recreation, and the needs to mitigate flooding. Green infrastructure has the potential to address all these concerns. It is recommended that planners consider greenways, green corridors, green spaces, green roofs in TOD areas if possible. Although green infrastructure could not solve the area’s flooding problem by itself, it has the potential to reduce the stormwater runoff and fulfill the community’s needs if implemented correctly;

4. Evaluate decentralized Wastewater System. Given the potential significant increase in sewer discharge, besides the expensive upgrade of the pipelines in centralized wastewater system, it is recommended to examine the possibility of using decentralized wastewater treatment, which can reduce the overflow incidents from centralized system and have the technical flexibility to relocate and adapt to the changing climate if extreme weather becomes more frequent. Decentralized sewer that put emphasis on wastewater recycling system can also reduce the demand on public water infrastructure and water resources.