Complex hydrological models are employed to mimic real world behavior and, if integrated with other hydrological complex models from different domains, may lead to a new powerful hydrological model that will provide answers to ever more sophisticated queries. However, integration will be a slow process since each hydrological model may be self-contained, with different timescales and simulation speeds. Electronic Design Automation (EDA) methodologies have evolved for chip design for precisely such situations, but in a different domain. Integration of hydrological models can benefit with such EDA techniques; there, however, is also an added advantage. A complete detailed model can take days to simulate and yield useful information to the end user. However, trading off precision in some sub models with overall system response time may be acceptable, thus returning useful information much sooner. We will present methodology, model, and simulation results for a hydrologic model that is based on concepts, languages, and tools used in EDA. This results in multiple models that can trade-off precision with response time. We hope this helps open many new lines of inquiries and potential practical uses.