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FUTURE BASIN DEVELOPMENT 5. This plan deals with storm runoff quantity. It does not address runoff quality for a number of reasons described in Section VIII. Thorough consideration of past reports by local governments, coupled with recent zoning maps of the City of Arvada for a planned development west of Rocky Flats, the Jefferson Center, indicated the reasonableness of adopting the UDFCD future land use projections. The Jefferson Center mapping indicates much more intensive land use west and south of the plant site than the UDFCD projections. Interviews with the President of the Jefferson Center development indicate that there will be a slow buildout of the center, but most likely, the Jefferson Center development's stormwater will be completely detained due to stringent downstream water quality standards. 6. The analysis of the plant site Core Area was done at a preliminary level to conceptually evaluate the drainage system needs and deficiencies. The study did not include detailed inspection of all drainage system components in the Core Area. The model used to analyze the Core Area drainage system included major drainage system elements. 7. The alternatives presented in Section IX are based on conceptual-level engineering to define possible solutions to drainage-related problems. Further study of each option would be required before implementation of the option. The land use projections outside the Core Area are considered reasonable for the year 2015; therefore, the year 2015 was used for the future development condition scenario. For the Core Area study, a high percentage of imperviousness was used to demonstrate the potential impact of total development of anyone basin or all basins of this 410 acre area and to indicate the type of flood runoff management required to adequately control an additional quantity of runoff. 8. Dam safety is not addressed. 9. There are newly installed, fully automated stream gages at several locations on the plant site being operated by consultants to EG&G and DOE. The hydrology described in the report is not calibrated to the measured flows from these gages because of the short period of record of the gages. Calibration of the hydrology to measured flow data can take place as more data are gathered. OUALIFICATIONS AND LIMITATIONS The scope of this Master Plan was limited to the analysis of the hydrology for the 2-, 5-, 10-, 25-, 50-, and 100-year flood events and the response of the drainage system to those flood events. Additional peripherally-related drainage issues were omitted from the study. The items omitted from this study include: 10. This Master Plan is based on the information available at the time of the investigation, and provides an indication of the status of the site at that time. A complete definition of the site conditions would require a more detailed investigation. Future conditions may change and further investigation may be required if conditions change. III 1. No analysis was done for the 500-year or probable maximum runoff events. 2. The analysis covered flood runoff events. No mass balance or zero-discharge analysis was done. 3. The study covers only surface water. Groundwater is addressed, but not analyzed. 4. The Master Plan does not specifically analyze all components of the off-site water management alternative, Option B, though some components of Option B coincide with the analysis.