Mathematical model of the Tesuque aquifer system underlying Pojoaque River basin and vicinity, New Mexico

Development and Application of Numerical Models to Estimate Fluxes through the Regional Aquifer beneath the Pajarito Plateau

“…Specific storage ( S s ) is of obvious importance, since lower values of S s will cause less water supply production to come from storage and more to come from surface water (either directly or as captured recharge). Hearne (1985) reviewed hydraulic tests conducted within the basin and concluded that a possible range for S s is 10 −4.5 to 10 −5.5 m −1 Our estimates (Tables 2 and 3) show the range of calibrated values for this model to be 10 −3.5 to 10 −4.4 m −1 The results presented above (parameter values shown in Table 2) are based on a value S s = 10 −4.3 m −1…”

“…It is impossible to use streamflow data alone to determine the proportion of this gain that originates beneath the plateau. The modeling study of Hearne (1985) assumed 316 kg s −1 total recharge to the Pajarito Plateau; McAda and Wasiolek (1988) assumed 291 kg s −1 lateral inflow from the Jemez Mountains. Based on streamflow data and transient head data, basin‐scale inverse modeling (Keating et al, 2003) indicated that approximately 253 kg s −1 of the gain to the river along this reach originated on the Pajarito Plateau and the Sierra de los Valles.…”

“…Many authors have identified the Rio Grande as the discharge point for the regional aquifer (Cushman, 1965; Griggs and Hem, 1964; Hearne, 1985; McAda and Wasiolek, 1988; Purtymun and Johansen, 1974; Theis and Conover, 1962). Previous reports have cited a variety of evidence to support this, including streamflow gain along the Rio (Balleau Groundwater, 1995; Purtymun and Johansen, 1974; Spiegel and Baldwin, 1963), measured vertical upward gradients in the vicinity of the Rio Grande (Cushman, 1965; Griggs and Hem, 1964), the presence of flowing wells (McAda and Wasiolek, 1988; McLin et al, 1996; Spiegel and Baldwin, 1963), and springs along the river (McLin et al, 1996).…”

“…Stone (1996) suggested that many of these springs may be discharging perched aquifers rather than the regional aquifer; unfortunately it is difficult to test these alternative hypotheses. It has been emphasized that although discontinuous, low permeability beds produce confining conditions in the aquifer locally near the Rio Grande and elsewhere in the basin, flow is able to cross the low permeability beds in some locations as groundwater discharges to the river (Hearne, 1985; Spiegel and Baldwin, 1963).…”

“…The Hearne (1985) model assumes no groundwater flow to the south; the McAda and Wasiolek (1988) and Keating et al models (2003) predict much larger discharge within the basin (to the Rio Grande) than to basins to the south. Keating et al (2003) estimated southerly flow from the Pajarito Plateau aquifer to the south to be approximately 9 kg s −1 Uncertainty analysis showed a possible range of values +34 kg s −1 or −62 kg s −1…”