  We present experimental results for water wave turbulence excited by
piston-like programmed wavemakers in a water flume with horisontal dimensions
6x12x1.5 meters. Our main finding is that for a wide range of excitation
amplitudes the energy spectrum has a power-law scaling, $E_\omega \sim
\omega^{-\nu}$. These scalings were achieved in up to one-decade wide frequency
range, which is significantly wider than the range available in field
observations and in numerical simulations. However, exponent $\nu$ appears to
be non-universal. It depends on the wavefield intensity and ranges from about
6.5 for weak forcing to about 3.5 for large levels of wave excitations. We
discuss our results in the context of the key theoretical predictions, such as
Zakharov-Filonenko spectrum $\nu=-4$, Phillips spectrum $\nu = -5$, Kuznetsov's
revision of Phillips spectrum (leading to $\nu=-4$) and Nazarenko's prediction
$\nu=-6$ for weak turbulence in finite basins. We measured Probability Density
Function of the surface elevation and good correspondence with the Tayfun
shapeexcept values near the maximum which we attribute to an anisotropy and
inhomogeneity caused by the finite flume size. We argue that the wavenumber
discreteness, due to the finite-size of the flume, prevents four-wave resonant
interactions. Therefore, statistical evolution of the water surface in the
laboratory is significantly different than in the open ocean conditions.
